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Gallery, Projects and General => Project Logs => Topic started by: Stilldrillin on September 06, 2010, 04:30:35 AM

Title: Robinson Hot Air Engine.
Post by: Stilldrillin on September 06, 2010, 04:30:35 AM
This arrived the other day. I believe it's a Poly Models 1/3 scale......

(http://i110.photobucket.com/albums/n95/Dayjo/P9030009.jpg)


(http://i110.photobucket.com/albums/n95/Dayjo/P9030012.jpg)


Very nicely machined and first off assembled/ unfinished. .....*(Edit, mid November...... Ignore that last sentence!).*.....

Complete with broken foot, and slightly bent crank. Which I did know about. No problem!  :thumbup:

Guess it's been dropped.......  :doh:


(http://i110.photobucket.com/albums/n95/Dayjo/P9030010.jpg)


Slipped a small piece of esbit under...... We have a runner!  :clap:

(http://i110.photobucket.com/albums/n95/Dayjo/P9030016-1.jpg)



Do I fill the rusty hole with water, and keep it topped up?

(http://i110.photobucket.com/albums/n95/Dayjo/P9030013.jpg)


Some form of instructions/ ideas would be appreciated. There's next to no mention of these engines on HMEM!  ::)
Title: Re: Robinson Hot Air Engine.
Post by: NickG on September 06, 2010, 04:42:18 AM
Nice looking engine,

Same as any hot air engine it's got a hot end and cold end. Looks like the top of the displacement cylinder does have a water jacket so yeah fill it with water. Looks like there's a drain on rear.

I would apply light oil to all joints, a drop on the displacer rod and oil the piston too.

Nick
Title: Re: Robinson Hot Air Engine.
Post by: madjackghengis on September 06, 2010, 07:38:20 AM
Well Still, that is a nice looking engine, a little tlc, and a couple of toes and half a foot, a spot of paint, and you've got a nice running display.  Can't say's I've ever seen one of those before, but it is interesting looking in its intersecting linkages, you ought to post a video of it, so we can hear it, too.  Very nice if I say so myself :bugeye: :thumbup: mad jack
Title: Re: Robinson Hot Air Engine.
Post by: Stilldrillin on September 06, 2010, 08:02:41 AM
Nick, Jack,
Thanks for your comments. I've been into the shed, with camera...... But!  ::)

With water, it's not as happy as was..........





Lurched to a standstill..... I had a closer look........ Water from shaft, and piston.  ::)





I didn't intend running it as is. It was bought to set up properly as an autumn project.

I would like to see a pic of component pieces/ whats inside, if anyone can help. Before I start having to prise the Hylomar joints apart......  :scratch:

David D
Title: Re: Robinson Hot Air Engine.
Post by: Stilldrillin on September 06, 2010, 08:39:10 AM
Jack,
Here's a vid of the real thing, at Stew's favourite Museum......

I saw this engine, and thought, hmmm, maybe, I could.....  :scratch:





Then a member of my other forum posted this, and I realised castings were available......

http://modelsteam.myfreeforum.org/about32786

Then, when this one showed up, on Ebay. I thought it would save on machining time.  :lol:

All within two weeks!  :thumbup:

David D
Title: Re: Robinson Hot Air Engine.
Post by: Bluechip on September 06, 2010, 10:40:17 AM
Hi Dave SD


Nice .... looks like it may have originated with ETW  ..

Although, if it had a commercial prototype, it would look like it .... appen ??

http://www.camdenmin.co.uk/hot-air-engines-c-329.html

EDIT ... might just be an illustration. Maybe the engine is not in the book ?? Dunno .. just ordered one anyway ...I will find out  :scratch:

Dave BC
Title: Re: Robinson Hot Air Engine.
Post by: Dean W on September 06, 2010, 07:43:38 PM
Thanks for the pics and video, David.  You know I'm thinking about it!..

Dean
Title: Re: Robinson Hot Air Engine.
Post by: NickG on September 07, 2010, 06:50:44 AM
Dave,

Strange ... appologies for my suggestion! Was there a bung in the rusty hole or was it open - I assumed it was open?

The plug in the end could be where the port has been drilled - somewhere there must be a transfer port between the top of the displacement cylinder and the bottom end of the power cylinder.

You'll no doubt want to take it apart anyway, but inside the displacer cylinder (big bit that flame goes under) there should be a loose fitting piston - possibly hollow or made up of discs. As I said, there must be a port connecting the two cylinders somewhere. Then there'll be a very good fitting piston in the power cylinder.

With a quick search on google I found this which may clear a few things up anyway and be of use in your rebuild:

http://users.moscow.com/oiseming/lc_ant_p/pic_Prj4.htm (http://users.moscow.com/oiseming/lc_ant_p/pic_Prj4.htm)

Not seen the videos but looks like a nice little project.

Nick
Title: Re: Robinson Hot Air Engine.
Post by: Stilldrillin on September 07, 2010, 08:11:30 AM
Thanks for that Nick!  :thumbup:

I had already found this one......

http://www.steves-workshop.co.uk/steammodels/robinson/robinsonindex.htm

The hole is left open.

The brass headed screw is an airway plug, I am sure. I think it's been fitted by a bad tempered gorilla, 'cos I can't shift it, yet. ::)

I would like to know how the air is supposed to transfer from displacer to piston, without picking up water on the way.

A couple of other jobs to do next....... Then I might find out, around the weekend! (http://forum.thescubasite.com/winking/winking0001.gif) (http://www.thescubasite.com)

David D
Title: Re: Robinson Hot Air Engine.
Post by: Stilldrillin on September 14, 2010, 09:59:51 AM
Well, I managed to get it apart without causing any damage. Apart from sawing off the end of the bent shaft, to remove the flywheel......

Hmmmm........

(http://i110.photobucket.com/albums/n95/Dayjo/P9140005.jpg)


Still not sure how the cooling water, and internal air, are intended to be kept separate.  :scratch:

Plenty of de rusting to keep me quiet/ mucky.  ::)

David D
Title: Re: Robinson Hot Air Engine.
Post by: Bluechip on September 14, 2010, 12:39:31 PM
Hi Dave

Looks like a suitable candidate for Darrens famous Battery Charger / Washing Soda trick  :zap:

Whats the top left doins made from .. looks a bit brassy? But maybe it's just the PC image.

A slosh of paint on the rusty bit might have been a good idea on first build.
It's the cold end, so it wouldn't need to be anything exotic. Says he, knowing little about it ..  :scratch:

Looks strange, would make some sense if the slot in the ( top row, 3rd from left ) was not there.
Otherwise it looks as if there is nothig to stop the displacer chamber filling with water.

Maybe I'm not seeing it correctly ??

Dave BC


Title: Re: Robinson Hot Air Engine.
Post by: Stilldrillin on September 14, 2010, 12:46:13 PM
Dave,

Hmmmm...... Yeah....... I was wondering who had done magic with rusty gloop, some time ago...... Ta!  :thumbup:

The top left doins is the hot cap. Made of brass, as is the displacer piston, next to it.

David D
Title: Re: Robinson Hot Air Engine.
Post by: Bluechip on September 14, 2010, 01:03:48 PM
Dave

Ah !!

That slot is the feed to the power cylinder, through the rib cast in the other bit, front 2nd left.

Can't see any sort of seal there though ??

How is the end of that air gallery wotsit supposed to seal to the displacer cylinder ?
Doesn't look any effective way of achieving that?
Bit missing ? Dollop of blue aardvark snot maybe?

Dave BC

EDIT  Not supposed to be an O-Ring or the like in the end of the gallery doins ??



Title: Re: Robinson Hot Air Engine.
Post by: Stilldrillin on September 14, 2010, 01:16:51 PM


Dave,
There's a male threaded tubey bit, (middle of 2nd left, front row), passes through the joint between 2nd left & top row 3rd left.

And, that's where it is probably leaking......

Will investigate further, sometime.....

O ring, or summat, imminent.......

David D

Title: Re: Robinson Hot Air Engine.
Post by: sbwhart on September 14, 2010, 02:25:42 PM
Interesting job you've got on their Dave.

I watched that engine for ages at Manchester trying to understand how it worked and failed.

Stew
Title: Re: Robinson Hot Air Engine.
Post by: Stilldrillin on September 14, 2010, 03:56:15 PM
Hi Stew!

Yes, I didn't see any explanation either!  Though, I did know about them.....  :thumbup:


I really loved the vacuum/ ratchet engine, which is behind you as you watch the Robinson. I'll post a vid, when I've got the time......  ::)

David D
Title: Re: Robinson Hot Air Engine.
Post by: Dean W on September 14, 2010, 07:08:57 PM
I see how it's supposed to seal, and it makes sense.  A gasket around the bolt hole pattern inside the large square/round/rusty casting.  Same gasket goes up, over, and back down on the spigot thing that goes in the slot in the cast part of the hot end.
Well, that's how I'd do it.  No water would get where it shouldn't. 

Thanks for the take-apart pic, David.  I needed to see that!  ; )

Dean
Title: Re: Robinson Hot Air Engine.
Post by: NickG on September 15, 2010, 08:12:04 AM
Yep,

Looking at the picture you need a gasket like that to make an effective seal between the transfer port and u semi circular cut out in top of displacer cylinder to stop air leaking into the jacket and vice versa. Bit like a sump gasket - they are usually rubber though.

Nick
Title: Re: Robinson Hot Air Engine.
Post by: Stilldrillin on September 15, 2010, 04:01:36 PM
Well,
I left a part in some vinegar overnight. Worked a treat. Rub with a toothbrush, rust gone!  :D

(http://i110.photobucket.com/albums/n95/Dayjo/P9150008-1.jpg)


Today was shopping day. At 13p a bottle, I stocked up..... Other parts are pickling now.  :thumbup:

(http://i110.photobucket.com/albums/n95/Dayjo/P9150006.jpg)



Dean, Nick. Not sure I understand your gasket theories. Sorry!  ::)

The port tube (if it is a through tube), is threaded at 90*, through the joint, but offset by some 75%.....

(http://i110.photobucket.com/albums/n95/Dayjo/P9150010-1.jpg)



Sorry, the female thread is out of focus!  ::)

(http://i110.photobucket.com/albums/n95/Dayjo/P9150011-1.jpg)



I  think this is the other end of the tube, and should have come out first. But, it won't unscrew, and the brass plug was a press (hammer?) fit.

Guess it will need drilling out.....

(http://i110.photobucket.com/albums/n95/Dayjo/P9150015.jpg)



Things should be clearer tomorrow, when the vinegar has done it's job.

David D
Title: Re: Robinson Hot Air Engine.
Post by: NickG on September 16, 2010, 05:15:46 AM
On the otherside of the casting where the port is, there must be a cross hole that lines up with a hole in the base of the power cylinder?
Title: Re: Robinson Hot Air Engine.
Post by: Stilldrillin on September 16, 2010, 06:16:32 AM
On the otherside of the casting where the port is, there must be a cross hole that lines up with a hole in the base of the power cylinder?


S' right!  :thumbup:

Pics later...... Me fingers are filthy, and smell like a pickle factory. All the rust is (almost) gone though!  :D

David D
Title: Re: Robinson Hot Air Engine.
Post by: NickG on September 16, 2010, 07:03:00 AM
Haha, good work David  :thumbup:
Title: Re: Robinson Hot Air Engine.
Post by: Stilldrillin on September 16, 2010, 12:43:43 PM
Here's a pic of an 'ole, for  Nick......

(http://i110.photobucket.com/albums/n95/Dayjo/P9160014.jpg)



The tube is in permanently, as far as I'm concerned.
Someone previously, has opened the engine without withdrawing the tube first. Hence the "threaded slot" in the displacer housing, where the tube should screw in place.  ::)

A little cleaner than yesterday. Wonder why the bronze flange ring?

(http://i110.photobucket.com/albums/n95/Dayjo/P9160006.jpg)



Here's how it fits.....

(http://i110.photobucket.com/albums/n95/Dayjo/P9160009.jpg)



And here's the inside view......

(http://i110.photobucket.com/albums/n95/Dayjo/P9160007.jpg)



I don't think I will have much bother sealing it. (Famous last words?).....  :thumbup:

David D
Title: Re: Robinson Hot Air Engine.
Post by: NickG on September 17, 2010, 03:25:19 AM
Thanks David, I can sleep much easier now i've seen the 'ole!

Naa, should be an easy job to seal it you may find it'll run a lot better once that's done!

 :thumbup:
Title: Re: Robinson Hot Air Engine.
Post by: Stilldrillin on September 17, 2010, 04:03:22 AM
Thanks David, I can sleep much easier now i've seen the 'ole!

Naa, should be an easy job to seal it you may find it'll run a lot better once that's done!

 :thumbup:

Nick,

Internally, engine and water jacket were covered with wet claggy rust. None of the body screws were tight.

No seal around the 'ole. Stripped/ hammered in, tube plug.

Bent crank.

      But, it would still run!! 

I think performance will be improved, after I've finished....... :thumbup:    :D

David D
Title: Re: Robinson Hot Air Engine.
Post by: NickG on September 17, 2010, 04:16:12 AM
Can't wait to see the results! :)
Title: Re: Robinson Hot Air Engine.
Post by: Stilldrillin on September 26, 2010, 11:01:20 AM
Well, I've finally got around to having a look at things, and making a few notes......

(http://i110.photobucket.com/albums/n95/Dayjo/P9260004.jpg)


I've also ordered new 4 & 6BA screws.

Do I paint inside the castings? Inside engine and water jacket?

I will not use "water" in the future, only coolant, or top up antifreeze/ summer coolant.

I can make a new steel section for the broken foot. Do I silver solder it in place?

David D
Title: Re: Robinson Hot Air Engine.
Post by: madjackghengis on September 27, 2010, 01:03:11 PM
Stilldrillin', if I may humbly offer a suggestion, I would find some soft cast iron and use it to repair toes and feet, and silver solder it on, as it always looks better than steel on cast iron, and it matches the thermal expansion rate as well.  Try to ignore the drool I leave on this post, as I look at all your parts and imagine putting them together in my own shop for my own running pleasure.  You've got a real "peach" there, and it should be a real runner when you get it all done.  I'm looking forward to the finished machine, running in a video.   :mmr: :poke: mad jack
Title: Re: Robinson Hot Air Engine.
Post by: Dean W on September 27, 2010, 10:33:09 PM
David, I shall jump in line behind Jack with drool apologies.  Maybe American are just a bit.. drooley.  I dunno.  Watching since the start, I'm still enjoying your restoration thread here.  Oh, and I still really like this Robinson.
Considering how much rust you found, I would paint it inside.  If you heat it without coolant, it is bound to condense some moisture
in there.  Don't you think?

Dean
Title: Re: Robinson Hot Air Engine.
Post by: Stilldrillin on September 28, 2010, 04:21:27 AM
Thanks for your replies Chaps!  :thumbup:


Jack,
Just remembered....... I bought 2 cast iron weights from a car boot sale some months ago, 2lb & 1kilo. Hacksaw time!  :D

I was unsure if cast iron could be silver soldered, by me. (Only done silver soldering once before).  ::)


Dean,
Yes, I agree re-moisture. Common sense really......  :thumbup:

The recent weather has reminded me, winter is coming, and my workshop becomes a very uncomfortable place......

I have improvement plans for this engine. Thermo syphon cooling. Ballrace bearings etc.
But, the sensible thing will be to rebuild, to get a reliable runner. Then improve as time & weather allow.

David D
Title: Re: Robinson Hot Air Engine.
Post by: madjackghengis on September 28, 2010, 10:43:44 AM
Hi David, high temp silver solder works well with cast iron, lots of flux, and cleaning with an etchant or the electrolosys with washing soda, although I prefer powdered draino to remove all traces of oil from the pores, sodium hypochloride I believe, although your vinegar seems to have done a fine job so far of cleaning it up.  Definitely paint the inside as it will improve the operation of the engine as well as reduce maintenance.  When you are up and running, and working on efficiency, try stainless steel for a displacer, you can often find cans or tubes that can be modified to fit, used fuel filters for fuel injected cars are good cans, and stainless is a bad heat conductor as you probably know.  If I didn't have so many projects already, I'd probably take a stab at mimicking your engine out of bar stock, it looks great, and does interesting things with the linkage, which always attracts the attention of bystanders.  We Americans don't always drool, sometimes it collects in our whiskers on our chin and we can wipe it off before it falls, particularly as fall approaches, and the whiskers are allowed to grow.  Thanks so much for showing a very interesting engine, an amazing engine, given it ran with everything wrong with it.  Looking forward to a video when it is up and running again. :jaw: :nrocks: mad jack
Title: Re: Robinson Hot Air Engine.
Post by: Stilldrillin on November 05, 2010, 01:37:24 PM
Well.
Now got a little time to sort Mrs. Robinson......  :thumbup:

Decided to rebuild to the "first run" stage, and get it right. Rather than try to complete in one go.....

Sorted a few problems along the way. Airway plug. Grooved piston. Added extra gasket to the base flange, for insulation.

1 piece of Esbit. Got a runner.......

(http://i110.photobucket.com/albums/n95/Dayjo/PB050029.jpg)


After a few minutes warm up, she slowed. So, I added "water", (Bluecol top up coolant). Picked up! Ran faster!  :clap:

Until the boiling radiator noises started, along with the steam......  :bang: :bang: :bang:

She's in disgrace, in pieces again!  :scratch:  ::)

David D
Title: Re: Robinson Hot Air Engine.
Post by: sbwhart on November 05, 2010, 01:46:46 PM
Perhaps its needs a Dustin Hofman to sort her out like in the film

 :D :D :D :D

Good work Dave

Stew

Title: Re: Robinson Hot Air Engine.
Post by: Stilldrillin on November 05, 2010, 01:52:09 PM
Possibly, Stew!  :thumbup:

But, I certainly aint any Graduate........  ::)


Good work? Not sure about that, until she runs properly.

Thanks anyway!  :wave:

David D
Title: Re: Robinson Hot Air Engine.
Post by: Stilldrillin on November 05, 2010, 04:49:53 PM
I've got a bit of a conundrum......  :scratch:

Need to treat every part/ joint which might leak. Starting from here, underneath the top cover......

(http://i110.photobucket.com/albums/n95/Dayjo/PB050030.jpg)


It might be leaking between the bronze ring and casting. Can't remove the 1/8 BSPT tube. So, can't remove the ring.

I've boiled it in washing powder to degrease, and intend to run a bead of Heldite jointing compound around inside & outside of the ring.

Anyone got a better idea?

David D

Title: Re: Robinson Hot Air Engine.
Post by: Bluechip on November 05, 2010, 04:56:27 PM
Nope, no idea, but ...

How does the 1/8" BSP tube rotate to screw into ... well, whatever it screws into ??

Dave BC
Title: Re: Robinson Hot Air Engine.
Post by: Stilldrillin on November 05, 2010, 05:02:40 PM
Nope, no idea, but ...

How does the 1/8" BSP tube rotate to screw into ... well, whatever it screws into ??

Dave BC

Dave.
There was a screwdriver slot spanning the outer end of the tube.

Only, the screw plug was jammed in so tight, it broke off!   :loco:

The only way out now, is to drill the whole tube away.......  :bang:

David D
Title: Re: Robinson Hot Air Engine.
Post by: Bluechip on November 05, 2010, 05:19:36 PM
Maybe that is the problem. I would guess that the screwed end is there to make a fluid-tight joint ??

When you first posted pics. I could not work out why the U-shaped slot was there.

Would not be too difficult to remove the tube on a lathe, strapped to the cross-slide?

Sez he, not having seen it ...  :scratch:

Do you have a drawing of it? Is the tube supposed to be just a tightish fit in that cast rib?

Is it gobbed up with some sealant to stop any fluid going up between the tube and it's hole? ie Can it be driven out? A blast of heat often weakens any sealant.

EDIT

Crap, my brains stopped again .... remembered ..

Is it possible to tap the inside of the stuck tube, and draw it out with a 'studding/ washer/nut/tube' puller

Dave

As 1/8" BSP is .383" nominal, I bet a 3/8" drill will be OK. Maybe the bit of tube wall left would collapse?

Baffled .. again .. just getting over a lousy head cold ...  :(

Dave BC





Title: Re: Robinson Hot Air Engine.
Post by: sbwhart on November 05, 2010, 06:12:18 PM
Dave

How about putting a screwdriver slot across the bit of tube sticking out, then put a length of bar through the hole that has a cross hole in the end, then slip a bit of silver steel through the cross hole so that it engages with the slot, so it work like a backward, if you see what I mean  :loco:

Hope this helps

Stew
Title: Re: Robinson Hot Air Engine.
Post by: shoey51 on November 05, 2010, 10:42:10 PM
Nice one David pity it wouldn't run for when we were in STLL
cheers Graham
Title: Re: Robinson Hot Air Engine.
Post by: Stilldrillin on November 06, 2010, 03:27:15 AM
Dave, Stew.
Thanks for the thoughts and ideas.......  :thumbup:

Wish I'd used your backward extractor before the slot broke up Stew!  ::)

Anyroad. I'll post a caddycrappy sketch, when I get the chance. That might explain better than my words can

Can't strip any further, without needing to make replacement parts....... Does jointing compound around the ring make sense?

Or, Should I just bite the bullet, and rip it apart?  :scratch:


Graham.
Didn't we have a great day at STL!  :D

She will be running for the next one! Hope you and Jilly are there to see it.....  :wave:

David D
Title: Re: Robinson Hot Air Engine.
Post by: NickG on November 07, 2010, 04:36:42 AM
David,

Do you think the leak is between base and bronze ring? It should be fairly easy to seal that with a fillet of sealer around the inside diameter, or even epoxy resin like araldite, just glue the thing in place. Maybe try PTFE tape wrapped around the tube, quite a few wraps if you can get underneath it?

Failing that, are you going to run it for prolonged periods of time? I know this isn't the point ... but you could just seal it up as best you can and leave it air cooled!

Nick
Title: Re: Robinson Hot Air Engine.
Post by: Stilldrillin on November 07, 2010, 05:58:41 AM
Nick.
This is this morning's condition.....

(http://i110.photobucket.com/albums/n95/Dayjo/PB070036.jpg)


Sealed all round with Heldite. Curing gently on a radiator. Tomorrow, mebbe, I'll re assemble, again.....  ::)

All I want it to do, is do what it does/ can, reliably....... Then, I'll do the mods over winter.  :thumbup:

I know they have trouble getting rid of the excess heat. Water jacket holds 30cc. only. A thermo syphon system seems the way to go. Also, a chimney from the top of the skirt. Mebbe ballrace crank bearings.

The possibilities are (almost) endless. Once I can get her running leak free......  :D

David D

Title: Re: Robinson Hot Air Engine.
Post by: NickG on November 08, 2010, 05:44:19 AM
David,

Looks to me like that should work  :thumbup: - if that doesn't seal it up what will! Might be worth layering the ptfe tape over that threaded section when you build it back together? Might be worth a try.

I like the sound of your mods, do you think the quality of the castings look good? I'm considering it as it's reasonably priced from Bruce Engineering. You may have said before but what is the approx. dia. of the flywheel so I can get an idea of scale?

Cheers,

Nick

Title: Re: Robinson Hot Air Engine.
Post by: Stilldrillin on November 08, 2010, 12:53:26 PM
David,
I like the sound of your mods, do you think the quality of the castings look good? I'm considering it as it's reasonably priced from Bruce Engineering. You may have said before but what is the approx. dia. of the flywheel so I can get an idea of scale?
Cheers,
Nick

Nick.
If I had the confidence. The time. A better lathe etc, I would have a go at making one..... I could do a much better job than this one!  ::)

Have a good look here. This is done with lots more forethought....   http://www.steves-workshop.co.uk/steammodels/robinson/robinsonindex.htm

The flywheel is 4.5" dia.

Running again, (dry), this afternoon......  :thumbup:

David D
Title: Re: Robinson Hot Air Engine.
Post by: Stilldrillin on November 08, 2010, 03:58:05 PM
Well...... Am I thick, or what!? The reason for the bodge has just dawned on me....... :bugeye:

The builder has measured the depth of the top casting, to fit the cylinder spigot.... .. And forgotten to include the thickness of the steel cover plate!  :doh:

The spigot was then too short. Adding only a ring to make up the length puts the 1/16"BSPT thread through the joint.

I would have shortened the spigot by another 8mm or so, and grafted a piece back on, to give correct overall length. The taper thread would then have passed through a solid cylinder wall.

I think it is called hindsight.......  :bang:

Keep calm, and carry on.

David D
Title: Re: Robinson Hot Air Engine.
Post by: madjackghengis on November 10, 2010, 08:29:50 AM
Well David, it sounds like you've found the fix to make that a real runner, and you may well have gotten that engine because the previous owner didn't appreciate the performance it had, and didn't know what to do about it.  I was kind of hoping to hear you decide to pull, twist or drill out that pipe, and fix it in place as it was intended, so you can get the full pleasure out of your engine.  With the ideas of circulating coolant that you have expressed, and finding this glitch, and having a plan that will fix it, I think you'll find the engine will run much better, and far more reliably giving you time to take real pleasure in it.  I'm still pouting a bit for it being yours and not mine, but I've got enough hair on my chin by now, the drool no longer drips down noticably.  I think your running video, for the finish, will be substantially different, and more enthusiastic, now that you've got a cure for that leak.  That engine almost looks like a crowd, with all its parts moving when it's running full up, a real looker.  I would definitely paint the inside with a top quality paint, and you won't be tearing it down some time down the road because of rust and nastiness leaking out from the inside.  Fine work on chasing down the cause, and finding the missing distance. :bow: :bugeye: :poke: Now I'm really looking forward to a finished video :jaw: mad jack
Title: Re: Robinson Hot Air Engine.
Post by: Stilldrillin on November 10, 2010, 12:57:57 PM

Thanks for your encouraging words Jack!  :thumbup: The fun (circus?) continues......  :wave:

I had thought to make the most of what was provided by the builder. But, not any more!   ::)

The lady's not well......   :scratch:

[ Invalid YouTube link ]



But, after a steamy few minutes......  :thumbup:


[ Invalid YouTube link ]



This was running "dry". Lasting about 15 minutes from cold, until the top end is too hot, for correct function.

Stripdown time ....... Again!  :bang:

Will try to correct the problems correctly, this time!  :smart:

David D
Title: Re: Robinson Hot Air Engine.
Post by: Rob.Wilson on November 10, 2010, 01:06:22 PM
Its a Sweet runner David  :thumbup:

I hope you get the leak sorted  :dremel:


Rob
Title: Re: Robinson Hot Air Engine.
Post by: NickG on November 10, 2010, 06:06:51 PM
David,

It seems to run really well, if only the builder had paid as much attention to the sealing faces etc as he had to the fits of the piston it would have been great. I'm sure you will fettle it though.

 :thumbup:

Nick
Title: Re: Robinson Hot Air Engine.
Post by: Dean W on November 10, 2010, 07:23:09 PM
Ran quite well in the second vid, David.  Nice and smooth.  The first vid kind of made me smile.  Not laughing at you,
but at the stirling engine that gave off an exhaust gas cloud! 
Title: Re: Robinson Hot Air Engine.
Post by: Bogstandard on November 11, 2010, 02:39:57 AM
David,

I don't know much about this type of Stirling engine, but could you rig up an external 'tin can' radiator to keep it well supplied with cooling water. It could be a semi sealed system, with only the tin can having an open top.

The circulation should be automatic, by convection.

I have shown the water level as being below the top plate, but if it didn't caused any internal engine leaks, it could be above.


John
Title: Re: Robinson Hot Air Engine.
Post by: madjackghengis on November 11, 2010, 10:16:11 AM
Hi David, in watching your two videos, I've concluded I will have to end up duplicating that engine sometime in the not too distant future.  As you, I like an engine that does something interesting and that one is among the more interesting I've seen and makes a fine "table engine", even a wife could find acceptable, maybe.  I hope to see it running with coolant soon, and the system closed up properly as it was originally intended to.  I expect you will get a bit more speed, and a bit more longer running that way, and it will be worth the extra work to set it all to right I expect.  Very well done. :thumbup: mad jack
Title: Re: Robinson Hot Air Engine.
Post by: Stilldrillin on November 11, 2010, 03:49:35 PM
Thanks for all your comments Chaps!  :thumbup:

Stripped it again, this afternoon.
The only problem with a forum, your failures are public, as well as occasional triumphs.  :doh:

John, that is the way I intend to cool it. When/ if I get it sorted......   ::)

David D
Title: Re: Robinson Hot Air Engine.
Post by: Bogstandard on November 11, 2010, 04:06:04 PM
Forget the failures David. We can't have perfection all the time.

It is the doing that counts.

John
Title: Re: Robinson Hot Air Engine.
Post by: Stilldrillin on November 12, 2010, 12:20:05 PM
Bitten the bullet!  ::)

Screwed a piece of screwed rod into my carefully tapped plug threads. Gripped in the vice, and beat L out of it with me lead tup....  :thumbup:

The ring had a drill dimple/ false start at it's inner edge. Got a blade under and levered it out....  :thumbup: (again).


(http://i110.photobucket.com/albums/n95/Dayjo/PB120002.jpg)


Now, we're at rock bottom..... The only way is up, perhaps!

David D
Title: Re: Robinson Hot Air Engine.
Post by: madjackghengis on November 12, 2010, 12:34:05 PM
Hi David, it looks like you've got to the bottom of all of it, and now there is no way but up.  I expect you will have a much better running engine now that you are fixing it from before the screwup of the previous owner, and not having to contend with his errors any more.  It's good to see the pipe removed, and the prospect of having a fully sealed system allowing full cooling, and full engine pressure.  Sometimes there's just no substitute for a heavy hammer well applied. :poke: :bugeye: Looking forward to the return of the parts properly, to their appropriate place, and the video of it running like a scalded dog.  :lol: mad jack
Title: Re: Robinson Hot Air Engine.
Post by: Bluechip on November 12, 2010, 12:37:56 PM
Well Done that man ....  :thumbup:  :thumbup:

I had every confidence in you ...

Onward and Upward ...

Dave BC
Title: Re: Robinson Hot Air Engine.
Post by: sbwhart on November 12, 2010, 02:55:18 PM
Well Done Dave

You can't beat a good wellying wif a big ammer.

Now you'll get it sorted proper.

Stew
Title: Re: Robinson Hot Air Engine.
Post by: Dean W on November 12, 2010, 06:21:50 PM
There ya go, David.  "Don't force it... just get a bigger hammer!"
And, "If it ain't broke, you're not hitting it hard enough".
Title: Re: Robinson Hot Air Engine.
Post by: NickG on November 12, 2010, 06:24:04 PM
Well done David, now just don't try taking it to bits any further now  :lol:

You'll definitely sort it once and for all now, just like the builder should of. To be fair, I think he's done  a better job on it than I could though!

Nick
Title: Re: Robinson Hot Air Engine.
Post by: Stilldrillin on November 15, 2010, 03:49:11 PM
Well, the ascent has started.  :thumbup:

Some months ago, I bought meself a couple of pieces of cast iron, 1 each, at a flea market. I was thinking flywheels, at the time. :scratch:

Looks just the ticket.....

(http://i110.photobucket.com/albums/n95/Dayjo/PB150006.jpg)


Turned a spigot on both ends. Time to bore out......

(http://i110.photobucket.com/albums/n95/Dayjo/PB150011.jpg)


Largest drill I've got, 16mm......

(http://i110.photobucket.com/albums/n95/Dayjo/PB150013.jpg)


At knock off. After some time spent boring through at .020" a pass, the hole is now around 1"+.

David D
Title: Re: Robinson Hot Air Engine.
Post by: shoey51 on November 16, 2010, 01:46:43 AM
doing a grand job there mate keep up the great work :clap:
Title: Re: Robinson Hot Air Engine.
Post by: Stilldrillin on November 16, 2010, 12:40:29 PM
Thanks Graham!  :thumbup:

Three sessions today..... Had to keep resting the motor, as I could smell hot paint, or summat!  ::)

This project has made me realise the pifflin' power output of a 7x12.

Started off at 20thou passes. Finished, only just managing to pull 10thou, though things were a little hot......  :bugeye:

(http://i110.photobucket.com/albums/n95/Dayjo/PB160017.jpg)


Got the bore roughed, 2.25 (-1/32")

(http://i110.photobucket.com/albums/n95/Dayjo/PB160018.jpg)


Hope the o/d is a little easier. Don't like overloading things!


Title: Re: Robinson Hot Air Engine.
Post by: Bluechip on November 16, 2010, 02:00:29 PM
Dave

Oooh Dear .... you might do well to strip that motor   :(

Is it anything like 600w as per a Chester Conquest (20?) Mill, 'cos someone I know had a stinky motor after being used a lot on one of those, and we just saved it I think.

Briefly, he said the motor pongs and it's a bit stiff to turn, but it does turn. Not the mill spindle, 'cos it turns freely in neutral.
Not good sez I.
You may have got it so hot that it's taken up the end clearance on the armature. Give it a good hour or so to cool, see if it's freed off.
No, did not.
Will it free with use ?
No. Take it off. See whats really happened.

Some little black bits fell out, what are they?
Dunno. but not normal. Leccy motors never need a de-coke...

OK. Strip it. Take the brushes out. Remove the tie bolts.

It appears that there is some soft white jollop to take up clearance in the winding slots. This had got hot, melted, and run between the magnets and armature. There to carbonise with friction.

So, told him to very carefully remove any white bits that looked out of place, clean out the motor , re-assemble and give it a go.

Success. Motor free ..

Just tried to phone him, but he's away in Denmark. But his wife says she thinks 'he fixed the motor, and it's still OK'

He ??? I spent about 2 hrs on the phone, and sent some 5 e-mails with sketches ... spoon feeding the twerp ... Grrrrrr


May not be any relevance to your motor Dave, but ... if it saves one ..

Dave BC












Title: Re: Robinson Hot Air Engine.
Post by: Bogstandard on November 16, 2010, 02:46:31 PM
For goodness sake Stilldave, if it starts smoking, grab the vacuum and suck up all the smoke and save it in a jar. If you lose that, you will never get the motor running again.

Bogs

Title: Re: Robinson Hot Air Engine.
Post by: NickG on November 16, 2010, 03:33:30 PM
For goodness sake Stilldave, if it starts smoking, grab the vacuum and suck up all the smoke and save it in a jar. If you lose that, you will never get the motor running again.

Bogs



 :lol:

I'm surprised you managed to drill 16mm to be honest!  Good work David, what's going to be different between this and the old one and how are you going to make the flange?

Nick
Title: Re: Robinson Hot Air Engine.
Post by: Stilldrillin on November 16, 2010, 04:01:29 PM
Dave, John.
Thanks for the concern, and smiles Lads!  :thumbup: :clap:

I don't think there will be a problem..... Probably!  ::)

Frankly, it smelt of hot paint after some 15 mins of ploughing. So, each time, I went and did something else for an hour or so.

At knock off, I shovelled out the black dust, and oiled round. Realised the headstock wasn't even aired, so I nipped the taper bearings a little, then ran it free for a few mins.

All ok, I reckon!  :thumbup:


Nick.
Essentially, I intend to face off the 6BA screw holes, including the part thread. Reduce the wall thickness by half, back to the neck, behind the small dia cover flange.

The counter bored new piece will slip over, held with some high temp sleeve lock, now on it's way from America.

I will then bore and turn to correct dimensions, with a larger dia cover plate flange, fitting into a thicker (3mm) steel cover plate. (Cos that area leaked as well).


Well..... That's the plan...... Probably!  :scratch:

David D
Title: Re: Robinson Hot Air Engine.
Post by: NickG on November 16, 2010, 04:05:45 PM
Ahh, I see now... good plan, I think  :scratch:  :lol:

Nick
Title: Re: Robinson Hot Air Engine.
Post by: sbwhart on November 17, 2010, 01:47:28 AM
Looks like you've bin whipping them horses Dave

 :whip: :whip: :whip: :whip: :whip:

You can't beat making your kit work for a living.

Fix looks good.

Stew

Title: Re: Robinson Hot Air Engine.
Post by: shoey51 on November 19, 2010, 02:01:23 PM
Looks like you've bin whipping them horses Dave

 :whip: :whip: :whip: :whip: :whip:

You can't beat making your kit work for a living.

Fix looks good.

Stew



im still confused but thats me generaly  :scratch: :coffee:
Title: Re: Robinson Hot Air Engine.
Post by: Stilldrillin on November 19, 2010, 03:59:27 PM
You're confused Graham??  (http://serve.mysmiley.net/confused/confused0070.gif) (http://www.mysmiley.net)

By 'ek lad...... Yer aught to try it from up close & personal!  :scratch:


No machining time today, but got a few minutes to sort through the box of parts... The bloody displacer is wobbling on it's shaft!! :bugeye: :bang: :bang:

The silver soldering has let go! It's only been in the box with the other parts....... Sigh........ (http://forum.thescubasite.com/mad/mad0270.gif) (http://www.thescubasite.com)

Still, I've got all winter to sort it. And, I guess that will open up a new discussion on how to make the best displacer.  :thumbup:

David D
Title: Re: Robinson Hot Air Engine.
Post by: Bogstandard on November 20, 2010, 12:48:22 AM
Dave,

I know exactly how you are feeling.

I used to restore or fix badly made or worn out engines, and things made by other people never seem to come up to your own expectations of how it should be done.

I think in your case, by the amount of fiddling and tweaking you have had to do, it would have been easier to make one from scratch.


John
Title: Re: Robinson Hot Air Engine.
Post by: madjackghengis on November 20, 2010, 09:24:28 AM
Hi Dave, I'm not confused, just seeing what I'm used to seeing in my own shop, in someone else's :bang:  Being on medical retirement from the Marines, I tend to be the recipient of other's junk and garage clean out, as that tends to be in my price range.  I think you're idea will work fine, I know you'll get a much better performance when the parts are all up to your own standards, and until then, you won't be happy.  Given you're going to have to do something with the displacer, I'd recommend you use a stainless steel can for it, if you can find one that is a fairly close fit, with little excess space.  I've got two cans I cut out of used fuel filters for fuel injected cars with the medium pressure pump in the tank, requiring sturdy filters in between.  Right now, I haven't found the suitable sized container/body to run them in, but if you go to a repair shop, it's quite possible you can find a filter can that matches your diplacer cylinder bore minus the necessary clearance, in their trash can.  Both my cans came out of cars I had to replace the filter in.  I'm looking for a tempered glass chamber close to the size, so the displacer can be watched, but that's a different story.  The less heat the can conducts north, the more efficient the displacer acts in its part of the whole heat cycle, and a brass one conducts too much heat if you can find a replacement.
   All that cast iron work looks good, and I like the fact you're doing a bang up job of cleaning up a mess left by someone else, and think it will make a great improvement in your engine, and won't be a niggling thing left in the back of your mind all the time.  As you can probably tell, I wish very much that had happened to be left on my own doorstep, but I won't be greedy.  It's enough to see you doing the good job.  Now I'm really looking forward to seeing it finished and running. I've copied pictures so I can try to fabricate something that cobles together to look close enough to get the cast iron charm and antique look that engine has.  If you needed to, you could even take a sheet of stainless steel ten or fifteen thousandths thick, roll it in a tube and silver solder it, and solder a top and bottom to it, to get a right sized can if you can't find one.  What's the actual i.d. of the dispacer bore, if you don't mind my asking?  I might be able to find something of the right size and either send you one, or send you looking in the right place to find one.  I'd be right proud to help a cousin across the pond, particularly one who has done such careful work on a cock up. :nrocks:  It'd be the least I could do, frankly. :headbang: mad jack
Title: Re: Robinson Hot Air Engine.
Post by: Stilldrillin on November 20, 2010, 12:34:43 PM

Dave,
I know exactly how you are feeling.

I used to restore or fix badly made or worn out engines, and things made by other people never seem to come up to your own expectations of how it should be done.

I think in your case, by the amount of fiddling and tweaking you have had to do, it would have been easier to make one from scratch.
John

Yer right John!
But, where would be the fun in that? I've always enjoyed "sorting things out", if I could......  :smart:

I am having fun..... Aren't I?   :thumbup:

Am I?  :scratch:

David D


Title: Re: Robinson Hot Air Engine.
Post by: Stilldrillin on November 20, 2010, 01:02:55 PM
Thanks for your ideas/ suggestions, Jack.  :thumbup:
But I think I'll leave the displacer thoughts, until this present section's sorted........  ::)

Finished roughing, at .005" per pass......

(http://i110.photobucket.com/albums/n95/Dayjo/PB200002-1.jpg)


I'm going to face off the 6BA threads, down to below the level of the part thread.....

(http://i110.photobucket.com/albums/n95/Dayjo/PB200005.jpg)


I'll then reduce the dia of the o/d by .1" per side, right through to the neck.
Then counterbore the new piece, to replace the o/d, and machine a larger flange.....

(http://i110.photobucket.com/albums/n95/Dayjo/PB200004.jpg)


The original flange is a bit small. Doesn't seal well on the 1/16" cover plate.
Making new 3mm plate with recess for flange, to replace......

(http://i110.photobucket.com/albums/n95/Dayjo/PB200009.jpg)


Unless anyone else has a better idea?  :wave:

David D



Title: Re: Robinson Hot Air Engine.
Post by: shoey51 on November 20, 2010, 01:23:11 PM
david looks good to me just watching on the side lines :thumbup:
Title: Re: Robinson Hot Air Engine.
Post by: Reckless_Engineer on November 20, 2010, 05:44:32 PM
A Top job so far david! This thread may come in handy whilst trying to convince the other half the pile of random metalic objects i have could come in handy one day  :clap:
Title: Re: Robinson Hot Air Engine.
Post by: Dean W on November 20, 2010, 06:09:02 PM
Now I get it, David.  Wasn't sure I understood when you first started on that piece of CI.  Makes sense,
and I think it will work as you are hoping. 
For that displacer, do you mean the can part itself?  I would use aluminum for that.  Make it as thin walled
and light as you are able.  Less mass going up and down will do nothing but help the situation.

Dean
Title: Re: Robinson Hot Air Engine.
Post by: Stilldrillin on November 21, 2010, 04:08:14 AM
Graham, Tom, thanks!  :thumbup:

Dean, Isn't aluminium too conductive? Isn't steel better?  :scratch:

Read somewhere, someone's used balsa wood......


Looking around the still uncleaned casting.

The hole for the air tube is quite generous.......

(http://i110.photobucket.com/albums/n95/Dayjo/PB200026.jpg)


Looking on t'other end, not much material left.

Err...... Wossat? ...... In't back corner?

(http://i110.photobucket.com/albums/n95/Dayjo/PB200024.jpg)


Gave it a poke and a proddle.

(http://i110.photobucket.com/albums/n95/Dayjo/PB200014.jpg)


Guess this is the source of the leak.......  :doh:

(http://i110.photobucket.com/albums/n95/Dayjo/PB200015.jpg)


SIGH......... Again........ (http://serve.mysmiley.net/sad/sad0145.gif) (http://www.mysmiley.net/free-love-smileys.php)

Wonder if this is the last of the glitches? ....... Nah.... Doubt it! :bang: :bang:

David D
Title: Re: Robinson Hot Air Engine.
Post by: shoey51 on November 21, 2010, 04:41:14 AM
looks nasty David but im sure you can handle it :thumbup:
Title: Re: Robinson Hot Air Engine.
Post by: NickG on November 21, 2010, 07:32:58 AM
I used aluminium for my displacer David, think it's pretty standard to have a hollow aluminium displacer with a very thin wall - same as hot cap to minimise heat transfer.

Good work.

Nick
Title: Re: Robinson Hot Air Engine.
Post by: sbwhart on November 21, 2010, 11:34:02 AM


Looking around the still uncleaned casting.

T
Err...... Wossat? ...... In't back corner?

(http://i110.photobucket.com/albums/n95/Dayjo/PB200024.jpg)


Gave it a poke and a proddle.

(http://i110.photobucket.com/albums/n95/Dayjo/PB200014.jpg)


Guess this is the source of the leak.......  :doh:

(http://i110.photobucket.com/albums/n95/Dayjo/PB200015.jpg)


SIGH......... Again........ (http://serve.mysmiley.net/sad/sad0145.gif) (http://www.mysmiley.net/free-love-smileys.php)

Wonder if this is the last of the glitches? ....... Nah.... Doubt it! :bang: :bang:

David D



TERMITES ?


Title: Re: Robinson Hot Air Engine.
Post by: Stilldrillin on November 21, 2010, 12:02:46 PM

TERMITES ?


 :lol: :lol: :lol: :clap:

Could be, Stew!  :thumbup:

I'm wondering what else could be lurking.......  ::)

Just keep calm, and carry on!

David D
Title: Re: Robinson Hot Air Engine.
Post by: Bogstandard on November 21, 2010, 01:25:38 PM
If you can Dave, get the whole inside surface sand blasted. Any little pockets of weakness like that will soon show up.

Then a bit of JB Weld or even soft solder will take care of it, just make sure you neutralise the flux afterwards.


John
Title: Re: Robinson Hot Air Engine.
Post by: Stilldrillin on November 21, 2010, 03:43:14 PM
If you can Dave, get the whole inside surface sand blasted. Any little pockets of weakness like that will soon show up.

Then a bit of JB Weld or even soft solder will take care of it, just make sure you neutralise the flux afterwards.


John

Thanks for that John!  :thumbup:

Because of the very thin wall, in places. I have ordered some 5/16" brass tube with .014" wall thickness. Intending to fix with sleeve lock.

This will leave a smooth bore for the air tube, with O rings, mebbe!

David D
Title: Re: Robinson Hot Air Engine.
Post by: Bogstandard on November 21, 2010, 04:19:21 PM
I never considered that Dave.

That should do just as well.


John
Title: Re: Robinson Hot Air Engine.
Post by: Dean W on November 21, 2010, 05:04:30 PM
Quite a lot of stirlings use aluminum for the displacer can.  It may be a trade-off between a dead weight you have to pick straight up,
and a bit of heat transfer.  On this design, the heat transfer should not be a big concern, since the power piston and displacer can are
not directly connected.  I.E., when the can gets hot, it will not be putting heat into the cold end, as it would on the type that has both the
power piston and displacer can in a common bore.  Did I put that in a way that it makes sense?

Dean
Title: Re: Robinson Hot Air Engine.
Post by: Stilldrillin on November 22, 2010, 02:03:46 AM
I can understand your reasoning Dean.  :thumbup:

Though this type of engine has problems, as the heat is directly underneath the skirt, with no easy exit.

I intend to fit a copper pipe chimney, as I have seen on others. This looks better than several radialy drilled holes, or slots.

I fitted 2 insulating gaskets, made from exhaust manifold cardboard/ metal material, either side of the hot cap flange. (The white line above the skirt).

Anyone got a better idea?

(http://i110.photobucket.com/albums/n95/Dayjo/PB050027.jpg)


David D
Title: Re: Robinson Hot Air Engine.
Post by: madjackghengis on November 22, 2010, 10:31:24 AM
Well David, from where I sit, it looks like you've got everything well under control.  I didn't mean to assume control of your project with regard to displacers, everything in hot air engines is a matter of trade off, and weight is equally a factor.  The main thing is plugging up all the leaks, which you've had to dig to find, and putting on a chimney is certainly a good idea, and will move lots of excess waste heat out of the way.  From the way it ran with all the problems, it ought to be a real powerhouse, now that everything is done up right, and patched up right nice and tidy.  That is an engine I'd keep in the living room, even if it did cause a bit of "discussion" between me and the Mrs.  I'm looking forward to the video when you're ready to run the engine, you've definitely done your share of the "building" of it, even if it was sort of together, when you got it.  I think your fix of the displacer chamber will be just what the doctor ordered. :beer:  cheers, mad jack
Title: Re: Robinson Hot Air Engine.
Post by: Stilldrillin on November 22, 2010, 11:49:06 AM
Thanks for that Jack!  :thumbup:



Did you get my PM, t'other day?.......  :scratch:

David D
Title: Re: Robinson Hot Air Engine.
Post by: madjackghengis on November 23, 2010, 08:22:48 AM
Hi David, I did just look at your p.m., forgot they exist, truthfully,  I think the model engineering kind of faded quite a bit for a while, and lots of what was available was pretty shoddy manufacture, but it seems to have picked up some, and there are lots of good quality casting kits out now, so hopefully we can look forward to better beginnings as we move forward.  I suspect your kit was one with too many flaws for someone who wasn't ready to find them all, and have a ready fix for them.  I always think such things are the best way to get a nice project at a cheap price, and pay up in work, to make up for to price.  Personally, I don't mind, I'd rather be in the shop anyway.  I'm looking forward to seeing how you set up your chimney, I think it'll make a big difference in the long run. :beer: :thumbup: mad jack
Title: Re: Robinson Hot Air Engine.
Post by: Stilldrillin on November 25, 2010, 04:02:14 PM
Well, the worst of the roughing is finally finished! (http://serve.mysmiley.net/happy/happy0165.gif) (http://www.mysmiley.net)

Sawed/ machined away the air tube, part thread. Also the flange......

(http://i110.photobucket.com/albums/n95/Dayjo/PB250017.jpg)


Then counterbored the new portion......

(http://i110.photobucket.com/albums/n95/Dayjo/PB250012.jpg)


We've got a new member in the inspection department

She's learning, slowly......

(http://i110.photobucket.com/albums/n95/Dayjo/PB250023.jpg)


Hmmmm......

(http://i110.photobucket.com/albums/n95/Dayjo/PB250019.jpg)


Tried for fit.......

(http://i110.photobucket.com/albums/n95/Dayjo/PB250025.jpg)


Passed, ready for assembly.....

(http://i110.photobucket.com/albums/n95/Dayjo/PB250029.jpg)


Now assembled, with high temp sleeve lock. Final machining, later.  :thumbup:

David D
Title: Re: Robinson Hot Air Engine.
Post by: shoey51 on November 25, 2010, 04:16:29 PM
nicely done David and a young machinist in the making :clap: :thumbup:
Title: Re: Robinson Hot Air Engine.
Post by: Bogstandard on November 25, 2010, 08:17:46 PM
David,

The only problem with using inspectors of such a young age is having to polish out the teethmarks afterwards.


John
Title: Re: Robinson Hot Air Engine.
Post by: Dean W on November 25, 2010, 09:43:13 PM
She looks like a very influence-able inspector to me, David.  I'm betting she could be bribed with a sweet biccy.
I know I can.  ; )
She's quite a doll!
Title: Re: Robinson Hot Air Engine.
Post by: sbwhart on November 26, 2010, 02:32:36 AM
That the way to go Dave start them young.

Nice picture, thats one for the album

 :thumbup: :thumbup: :thumbup:

My grandson is fascinated with wheels that turn, he sits on my knee at my computer desk happily turning my finger engine over and over its lost it polish with the sticky fingers,

Bin thinking of making him a wooden one for Christmas  :proj:

Stew
Title: Re: Robinson Hot Air Engine.
Post by: Stilldrillin on November 26, 2010, 03:16:53 AM

My grandson is fascinated with wheels that turn, he sits on my knee at my computer desk happily turning my finger engine over and over its lost it polish with the sticky fingers,

Bin thinking of making him a wooden one for Christmas  :proj:

Stew

Now, that's a great idea Stew!  :clap:

Something robust. For little hand, not finger, but not needing muscles to operate. Hmmm......  :thumbup:

David D
Title: Re: Robinson Hot Air Engine.
Post by: NickG on November 26, 2010, 03:37:55 AM
I always think it's a lovely idea to make people things for christmas - trouble is, I'd need to start in January if this idea is to work!  :lol:

Nice work David, have you thought of driving anything with this when the improvements are complete? I think it'll be powerful enough and with a convection water cooler it should run for a while.

Nick
Title: Re: Robinson Hot Air Engine.
Post by: Stilldrillin on November 26, 2010, 03:58:17 AM
I always think it's a lovely idea to make people things for christmas - trouble is, I'd need to start in January if this idea is to work!  :lol:

Nice work David, have you thought of driving anything with this when the improvements are complete? I think it'll be powerful enough and with a convection water cooler it should run for a while.

Nick

Nick,
I arrived here via the Steamtoys forum. Been watching wheels go round for several years..... Never driven anything!  ::)

Once things are running to my satisfaction, I seem to move on to another engine.......

I often have vague thoughts of making a water pump..... Then another orphan arrives, needing my attention!  :thumbup:

David D
Title: Re: Robinson Hot Air Engine.
Post by: Stilldrillin on November 26, 2010, 12:11:29 PM
Popped into workshop this morn, around 11-00. The top platform casting had been soaking in vinegar overnight.

It was covered with a layer of ice!  :bugeye:

I think it might be a while, before any more worthwhile progress is made.......  :doh:

David D
Title: Re: Robinson Hot Air Engine.
Post by: NickG on November 26, 2010, 02:32:43 PM
David,

I'm the same - have never driven anything either from any of my engines! I guess there's no point unless the engine is self sufficient i.e. an actual steam engine or a hot air engine, I could never see the point of driving something from an engine that's running on compressed air!

Brr, bit cold out there, that's why I'm continuing on my drawings tonight - if I can get off the internet!

Nick
Title: Re: Robinson Hot Air Engine.
Post by: madjackghengis on November 27, 2010, 10:19:33 AM
Hi David, sorry to hear about the ice, I didn't much like my shop in the winter, when I lived in Chicago, but yesterday was just cold enough for me to light a fire in my stove in the shop, and burn off an old cast iron skillet which needed to be cleaned and re-seasoned with fresh lard and burned in.  I am thankful I have both a large wood stove in my shop, and acres of woods which need cleaning out constantly, to supply wood for heat.  I always look forward to winter as the time to break out the casting equipment and melt some metal, while its cold, and the heat is fully appreciated.  I've got some bronze which needs melting and pouring, to make a cylinder for an engine.  I hope you get to get out in your shop again soon, can't let things go too long.  I'm considering making a rather large stirling engine whose hot end can stick down into my stove, which is a three hundred gallon propane tank, modified with a box and door for the wood, and would benefit greatly from a fan on the top run off the heat of the stove to circulate the hot air.  I think about this every fall, I reckon it's time to do something about it.  It's your fault, you said to do something useful with an engine :poke: mad jack
Title: Re: Robinson Hot Air Engine.
Post by: Rob.Wilson on November 27, 2010, 05:04:18 PM
Great few shots David  :clap: :clap: :clap: :clap:

I have one that thinks its fun to sit in the moulding bench and make sand castles with moulding sand  ::)


Rob  :D
Title: Re: Robinson Hot Air Engine.
Post by: Stilldrillin on November 28, 2010, 03:58:30 PM
I'm considering making a rather large stirling engine whose hot end can stick down into my stove, which is a three hundred gallon propane tank, modified with a box and door for the wood, and would benefit greatly from a fan on the top run off the heat of the stove to circulate the hot air.  I think about this every fall, I reckon it's time to do something about it.  It's your fault, you said to do something useful with an engine :poke: mad jack

Something like this Jack?

(http://i110.photobucket.com/albums/n95/Dayjo/P5120001.jpg)


It intrigues me on every visit to the Harrogate Mod Eng Show. Difficult to photograph. Never had chance to talk to the owner.

David D

Title: Re: Robinson Hot Air Engine.
Post by: sbwhart on November 28, 2010, 04:04:49 PM
I've seen that engine all over the country, I think the guys must spend all summer traveling around from show to show towing it behind his camper.

What a great way to spend summer.

 :D :D :D :D :D :D

Stew
Title: Re: Robinson Hot Air Engine.
Post by: Stilldrillin on December 10, 2010, 12:35:30 PM
While I can't get out there, to do something. I guess a bit of forward planning won't go amiss......  ::)

What's the green coloured additive, the stationary engine lads use in their pumps, at steam fairs etc?  :scratch:

The bluecol additive rusted overnight!  :bang:

Essentially, I need something to add to water, so it won't rust the engine internals. I can only think of soluble oil. (http://serve.mysmiley.net/confused/confused0083.gif) (http://www.mysmiley.net/free-facebook-smileys.php)

David D
Title: Re: Robinson Hot Air Engine.
Post by: Bluechip on December 10, 2010, 01:24:27 PM

What's the green coloured additive, the stationary engine lads use in their pumps, at steam fairs etc?  :scratch:

 

Chartreuse ???  :lol:

Can't see why Bluecol would have any effect. Anti-freeze is Ethylene Glycol AFAIK.
The rust will be caused by air in the water. Tried boiling it and letting it stand before use?
Vaguely seem to remember some demonstration with iron in distilled water, no rust 'cos no air ...

I think Glycerol itself is water miscible .. ?

Why not slap some paint on the inside? Cylinder block paint will stand a fair bit of heat, as will Bondaprimer, without going wild and using Sperex or the like . Does the rust afflicted part come in contact with the heat source .. ?

Can't imagine what it looks like in detail, so I don't know if paint is a sensible solution.

Dave BC



Title: Re: Robinson Hot Air Engine.
Post by: Stilldrillin on December 10, 2010, 03:34:16 PM
Dave.
I intend to paint inside and out with hammerite. But, there's always some water left in nooks & crannies, after running.

The Blucol top up stuff seemed very "wet". Strange stuff......  :scratch:

Hmmmm.......

David D
Title: Re: Robinson Hot Air Engine.
Post by: Dean W on December 11, 2010, 12:37:42 AM
A good brand of antifreeze should work great.  A kind with a rust inhibitor like Prestone.  A car engine will run for years
with that stuff in the block, and very little rust will form.  You mix it 50/50 with water.
Title: Re: Robinson Hot Air Engine.
Post by: madjackghengis on December 11, 2010, 08:57:44 AM
Hi David,  I've been going back over your postings, I seemed to have missed the photo of the "large stirling engine", must have been mesmerized with the cute photo of your newest inspector for the production line.  Looks like she's a "keeper", like John said, the worst is having to polish out the teeth marks.  That is a beautiful, large stirling engine. :lol:  Of course if it got in my shop, it would soon get hot, leave the paint behind in stages and flakes, and start looking like my stove, which won't stop rusting for some reason.  Must be the high heat and the cold cycling or something.  This build has been a real pleasure to follow, particularly since it gives me a basic concept type engine to copy, that would work with my stove, just a matter of adapting some aspects.  I'm glad I jumped back a page, and saw that engine I missed before.  :hammer:  great work on getting everything back toward where it should have been in the first place though.  :nrocks: mad jack
Title: Re: Robinson Hot Air Engine.
Post by: madjackghengis on December 11, 2010, 09:06:01 AM
Hi again David, I was going to say, running the engine with good quality anti-freeze will boil out the air from the water in time, I don't know how long in the stirling engine, but that's why you never get rust inside your car engine, if you keep fresh antifreeze in it.  It gets past boiling temperature the first time you drive it.  They make paints particularly for the inside of race engines, to make the oil run down the walls faster, and seal the pores of the block, it will stand five hundred degrees for years without any loosening at all, it probably wouldn't stand the direct flame, but would be fine for all the water filled parts.  I understand the fact that there's always another engine waiting, but sooner or later you have to run something with one, and then it becomes a new standard for operation if you're not careful. :headbang: mad jack
Title: Re: Robinson Hot Air Engine.
Post by: Stilldrillin on December 16, 2010, 08:39:42 AM
Thanks for your comments Chaps!  :thumbup:

I've decided to cool the engine using the top up solution.
Also, to dry out by piping air through, from an aquarium pump, for a couple of days afterwards.....


Looks as though the weather has closed me down again.....   :(

Only got a little bit done.  ::)

The top deck casting was machined barrel shaped, both sides!  :bang:

Drawfiled/ emeried .005", from the centre of this side......

(http://i110.photobucket.com/albums/n95/Dayjo/PC140002.jpg)


And .025" or so, from this side......

(http://i110.photobucket.com/albums/n95/Dayjo/PC140004.jpg)


Emeried out the rust, from the casting airway bore.....

(http://i110.photobucket.com/albums/n95/Dayjo/PC140007.jpg)


Fitted the 5/16" tube......

(http://i110.photobucket.com/albums/n95/Dayjo/PC140009-1.jpg)


Remembered to overlap the joint face area.
So it will butt against the new section of displacer housing, when I mill the new joint face ring.....

(http://i110.photobucket.com/albums/n95/Dayjo/PC140010.jpg)


Also, roughed out a new 3mm thick cover plate.......

(http://i110.photobucket.com/albums/n95/Dayjo/PC160005.jpg)


It's snowing like Billy Ho at the moment. Guess it will be some time before any more work gets done..... (http://serve.mysmiley.net/sad/sad0122.gif) (http://www.mysmiley.net/free-msn-smileys.php)

David D
Title: Re: Robinson Hot Air Engine.
Post by: NickG on December 16, 2010, 11:10:30 AM
Nice work David, it still feels good to get  abit done though. Strangely the cold hasn't effected me when I've actually been in the garage this winter, just laziness that prevents me!!

Nick
Title: Re: Robinson Hot Air Engine.
Post by: arnoldb on December 16, 2010, 12:17:01 PM
That's some nice restoration work David  :thumbup:

Keep 'em coming; I hope the UK weather lets up for you guys...

 :beer:, Arnold
Title: Re: Robinson Hot Air Engine.
Post by: Dean W on December 16, 2010, 07:19:36 PM
Looking good, David.  Getting those surfaces flat should make quite a difference.  Good job, that.
Title: Re: Robinson Hot Air Engine.
Post by: Stilldrillin on December 17, 2010, 02:00:24 AM
Thanks for your comments Chaps!  :thumbup:

Feeling well off it, at the mo.... Me and cold weather really don't mix...... (http://serve.mysmiley.net/sick/sick0023.gif) (http://www.mysmiley.net)

I dress accordingly, during my few (short) workshop  sessions. But still get chilled...... Shivers/ headaches for a couple of days afterwards.  ::)

I guess I'm not as young as I would like to be! :bang:


Ah, well..... Cheer up! Just looked at the forecast....... No change, for the next 14 days. (http://serve.mysmiley.net/sad/sad0120.gif) (http://www.mysmiley.net/free-sad-smileys.php)

David D
Title: Re: Robinson Hot Air Engine.
Post by: NickG on December 17, 2010, 03:20:27 AM
After my last post I have changed my mind .... had numb fingers last night!

Title: Re: Robinson Hot Air Engine.
Post by: DavidA on December 17, 2010, 07:16:09 AM
arnoldb,

....I hope the UK weather lets up for you guys..

No chance.  It doesn't really start again until tonight.

Dave.
Title: Re: Robinson Hot Air Engine.
Post by: Bogstandard on December 17, 2010, 07:31:25 AM
I keep telling you lads, do what I have done.

A smallish cheapo oil filled rad from Wilko's or somewher similar. Plug it in and leave it on. I put mine on well over a month ago and won't go off until around March.

My shop at this time is at about 60 degs F. Perfect for working in, and the machines don't feel too cold. But it does take a few days to reach a nice working temp.

They cost very little to run, all you have to do is make sure you have no draughts about the place.


John
Title: Re: Robinson Hot Air Engine.
Post by: Stilldrillin on December 17, 2010, 08:15:40 AM
I hear you John. But.

For the little shop time I get, even in the summer......

It would take me all summer to insulate, so I could notice any small heater improvement.

Really not worth constant heating, when I can only get up to an hour's playtime, several daytimes a week.

On/ off heating causes condensation.

In winter I catch up on other, indoor things..... Ancestry at the moment.

David D

Title: Re: Robinson Hot Air Engine.
Post by: andyf on December 17, 2010, 08:54:31 AM
David, you might consider getting a small version of the infra-red heaters used over outdoor pub tables. My rifle club has two 100' x 25' indoor rifle ranges, only used for 3 hours each evening, and we find infra-reds quite effective at keeping the chill off us on the firing point. They only heat what the radiation hits, so we aren't trying to warm up a vast volume of air in a poorly insulated building, and the effect is instantaneous. 

Andy
Title: Re: Robinson Hot Air Engine.
Post by: Stilldrillin on December 17, 2010, 11:51:51 AM
Thanks Andy!
I already have one of those infra red heaters! Bought new, 2 years back, and now forgotten, in the greenhouse.....  ::)

Will give it a whirl, when I feel ready to try again.  :thumbup:

We had them on our ranges too. Very welcome, when it was your turn to be RO. (http://serve.mysmiley.net/winking/winking0072.gif) (http://www.mysmiley.net/free-adult-smileys.php)

David D
Title: Re: Robinson Hot Air Engine.
Post by: andyf on December 17, 2010, 12:21:33 PM
Thanks Andy!
I already have one of those infra red heaters! Bought new, 2 years back, and now forgotten, in the greenhouse.....  ::)

Will give it a whirl, when I feel ready to try again.  :thumbup:

We had them on our ranges too. Very welcome, when it was your turn to be RO. (http://serve.mysmiley.net/winking/winking0072.gif) (http://www.mysmiley.net/free-adult-smileys.php)

David D

You've reminded me - it's my turn as RO on Monday night, buggrit. Met Office predicts -5C.  :(
Note how those tears seem to freeze as they hit the floor. And I bet not many turn up. Still, at least we have a separate clubroom with fan heaters.

Andy

Andy
Title: Re: Robinson Hot Air Engine.
Post by: shoey51 on December 17, 2010, 02:16:00 PM
I hear you John. But.

For the little shop time I get, even in the summer......

It would take me all summer to insulate, so I could notice any small heater improvement.

Really not worth constant heating, when I can only get up to an hour's playtime, several daytimes a week.

On/ off heating causes condensation.

In winter I catch up on other, indoor things..... Ancestry at the moment.

David D


is addictive David  :coffee:
Title: Re: Robinson Hot Air Engine.
Post by: DavidA on December 19, 2010, 01:08:33 PM
While most of my 'stuff' is in the big shed that is only heated up when needed, my 'machine shop' is heated constantly in this weather by a small electric greenhouse heater.  Keeps the place at around 12C. When the outside air temp gets back above freezing I will switch it back to four hours on-six hours off via the timer to save on fuel.
Really need to incorporate a room-stat in the circuitry to add a bit more control.

Dave.
Title: Re: Robinson Hot Air Engine.
Post by: shoey51 on December 22, 2010, 01:40:34 PM
I have the oposite problem I need to get Aircon installed to cool the workshop down
Title: Re: Robinson Hot Air Engine.
Post by: Stilldrillin on January 19, 2011, 03:59:52 PM
Well, it's been quite a while......  ::)

What with weather, health, family, friends.......
Even the new lass in the inspection dept has caused problems! She's been off for a fortnight.
Spent a few nights in hospital, for chopping and stitching together. She's back to her young self now, though......  :D

Just, had to grab a few minutes, whenever I could.  :thumbup:

Mounted faceplate on the rotary table. Centre adaptor bush, and the displacer bush screwed to the wrong side of the casting......

(http://i110.photobucket.com/albums/n95/Dayjo/PC310024.jpg)


This held the assembly central to the displacer housing bore.......

(http://i110.photobucket.com/albums/n95/Dayjo/PC310025.jpg)


Milled through the 3mm steel cover plate......

(http://i110.photobucket.com/albums/n95/Dayjo/P1060030.jpg)


(http://i110.photobucket.com/albums/n95/Dayjo/P1060033.jpg)


Swapped cutters and opened out the bore, and machined the lower, and upper joint faces.
Gave the cover plate an extra 5 thou' per side, for easier assembly, when painted......

(http://i110.photobucket.com/albums/n95/Dayjo/P1100007.jpg)


Finish turned the replacement section of the displacer cylinder. (That's not a false start, by the flange, it's the 5 thou' for paint)......

(http://i110.photobucket.com/albums/n95/Dayjo/P1190009.jpg)


Fits quite snugly.......

(http://i110.photobucket.com/albums/n95/Dayjo/P1190012.jpg)


Shows how the brass repair tube snugs up to the cylinder. Also, the plugged water hole......

(http://i110.photobucket.com/albums/n95/Dayjo/P1190011.jpg)



Next job was the chimney........

(http://i110.photobucket.com/albums/n95/Dayjo/P1140012.jpg)


Opened out carefully......

(http://i110.photobucket.com/albums/n95/Dayjo/P1140014.jpg)


Eventually, to 18mm......

(http://i110.photobucket.com/albums/n95/Dayjo/P1140015.jpg)



Then a bush, to adapt to a 15mm copper elbow.......

(http://i110.photobucket.com/albums/n95/Dayjo/P1190014.jpg)


Looks ok, I think......

(http://i110.photobucket.com/albums/n95/Dayjo/P1190016.jpg)


(http://i110.photobucket.com/albums/n95/Dayjo/P1190017.jpg)


Next up, is the in/ out coolant pipes.

That's it. For now!

David D
Title: Re: Robinson Hot Air Engine.
Post by: sbwhart on January 19, 2011, 04:17:53 PM
Cracking bit of machining Dave, looking real good

Hope your little inspector has made a full recovery and is doing well.

Stew

Title: Re: Robinson Hot Air Engine.
Post by: Dean W on January 19, 2011, 07:47:56 PM
You made a good show of that, David.  Even I can understand it!  ; )
Looks very good, and the chimney is a smart addition.
Title: Re: Robinson Hot Air Engine.
Post by: Brass_Machine on January 19, 2011, 11:48:03 PM
David,

Just found this thread. Missed it when it started. 1st, I love reading about how you restore engines. You do a great job. 2nd, what an interesting engine, I am with MadJack on this... I think I have to build one now!

Keep it up.

Hope the little one is doing better. What a cute one.

Eric
Title: Re: Robinson Hot Air Engine.
Post by: shoey51 on January 20, 2011, 02:09:23 AM
this is coming along nicely David I cant wait till the next instalment :thumbup:
Title: Re: Robinson Hot Air Engine.
Post by: Stilldrillin on January 20, 2011, 04:29:37 AM
Thanks for all your kind comments Chaps!  :thumbup:

Re the new inspector..... She was born with a cleft palate.

The Surgeon should be a member here, for his wonderful Moderfication......  :clap: :clap:

However he worked such magic. In a very confined area. Using only available materials, I shall never know!  :bugeye:

The man's a genius! They all are.......  :bow: :bow: :bow:

David D
Title: Re: Robinson Hot Air Engine.
Post by: Bogstandard on January 20, 2011, 04:42:13 AM
That engine has been given a new lease of life Dave, when it is all finished and running, you should be proud of yourself.

If you are going to give that base a coat of heat resist paint, maybe you could rebuild that broken foot with some epoxy based putty, shaped and filed to match the original. By the time the paint is on there, you would never know it had been broken. It would only need a few thin pins putting into the casting for it to grip onto, just to give it a bit of support and strength.


John
Title: Re: Robinson Hot Air Engine.
Post by: NickG on January 20, 2011, 05:09:07 AM
Nice 1 David, getting there and it's looking 1000 times better.

Nick
Title: Re: Robinson Hot Air Engine.
Post by: andyf on January 20, 2011, 06:17:42 AM
..... maybe you could rebuild that broken foot with some epoxy based putty, shaped and filed to match the original. By the time the paint is on there, you would never know it had been broken. It would only need a few thin pins putting into the casting for it to grip onto, just to give it a bit of support and strength.
John

Or even stand the base on a flat surface, put a light film of oil (release agent) on one of the good feet, build a little coffer dam round it with Plasticine or something, fill with plaster of Paris, and thus make a mould. Put some thin pins into the poorly foot, pop the mould on and fill that with poxy resin. That might reproduce the "as cast" surface finish.

Andy
Title: Re: Robinson Hot Air Engine.
Post by: Stilldrillin on January 20, 2011, 01:14:48 PM
John, Nick, Andy.
Thanks for your comments!  :thumbup:

Frankly the foot is some distance down the list, as yet..... I'm surprised you're recommending poxery resin. Will it stand the heat?  :scratch:

I was contemplating Jack's suggestion of a piece of cast iron and silver solder...... Though, I'm not confident at high temp soldering, as yet.  ::)

My main concern, is to get this project finished to running condition, ASAP. As a pal wants my mill and r/t etc.
He is offering very sensible cash for the assembly...... Allowing me to upgrade a little. :ddb:



One more step along the way, this afternoon.......

(http://i110.photobucket.com/albums/n95/Dayjo/P1200018.jpg)


Opened out to 7mm......

(http://i110.photobucket.com/albums/n95/Dayjo/P1200020.jpg)


Rather out of focus, 5/16" slot drill, 3/8" deep.......

(http://i110.photobucket.com/albums/n95/Dayjo/P1200021.jpg)


Leaving a small step in the bottom, to support the depth of the 7/8" long tubes......

(http://i110.photobucket.com/albums/n95/Dayjo/P1200025.jpg)


Looks ok, I think.......

(http://i110.photobucket.com/albums/n95/Dayjo/P1200027.jpg)


That's it until next week.
Busy weekend, including a 1st birthday party! (http://www.easyfreesmileys.com/smileys/free-party-smileys-817.gif) (http://www.easyfreesmileys.com/facebook-smileys.html)

David D

Title: Re: Robinson Hot Air Engine.
Post by: NickG on January 20, 2011, 03:15:15 PM
Looks great David, not ok!  :beer:
Title: Re: Robinson Hot Air Engine.
Post by: Dean W on January 21, 2011, 08:17:43 PM
Yes, looking very good David! 
With all the work you've done, this has been near the same as building the engine from the raw castings.

Dean
Title: Re: Robinson Hot Air Engine.
Post by: madjackghengis on January 22, 2011, 10:29:02 AM
Hello David, you've been moving along quite nicely since the inspector got out of the shop, and back at home, did you ask the surgeon if he was going to post a build log on the madmodder site?  Perhaps an invitation would have brought out the artist in him :lol:  glad to hear your little darling is going to be fine, bit of a start when you spoke of being in surgery and all, glad to know it was something easily fixed and not a major deal.  I think you've done a very nice job in thinking through your alterations, and you are going to end up with an engine that can be hooked up to something to do work, from the looks of it.  I would readily follow Bog's idea if I wasn't so sure a piece of scrap iron and the silver would do the job.  As he says, if it's going to get paint, you can always make it look right, but I'd still do the silver and iron or steel or for that matter, you could simply puddle up some brazing with a clay dam, with the whole sitting on a brick, and then file it to shape, and it wouldn't show with paint on it, and high temp paint will definitely stay on for quite some time, it stays on the heads of an iron head Harley sportster for about a year before it finally goes away, and they run hot, right on top.  I don't know if it's available or common there, but I get wrinkle finish high temp paint here, it's rated at seven or eight hundred degrees, and the wrinkle finish makes cast look great, and hides any cracks brazed up or the like.  I use it on all the Harley cylinders I bore and hone and fit for pistons because nothing else looks as good on engine cylinders of iron, and air cooled.  It dissipates heat well too.
   I think you've got a real piece of work there and very nicely cleaning up to run.  I'm really looking forward to seeing it finished, and watching the video.  :bugeye: :beer: cheers mad jack
Title: Re: Robinson Hot Air Engine.
Post by: Stilldrillin on January 22, 2011, 12:29:15 PM
Nick.
Thank you!

Dean.
Yes, you're right! But, I love sorting out orphan engines' problems......

The first Derbyshire Mineworker I ever met, told me. When there's a problem...... "Allus blame t'other shift".  :thumbup:

The buck stops here, on a first build!  :scratch:

Jack.
I've bought some dark green smoothrite, for the engine. Think I will do the skirt in black barbecue paint. That should stand the heat, and hide any lumps & bumps......



Right, then......

This air transfer tube has caused me a lot of thinking time....... Still not happy!  :scratch:

Can we have a committee meeting?   :smart:

This is what was originally fitted. Water could leak between tube and casting. (Never minding the termite holes!).  ::)
Around 3" long. 5/16" o/d. 5.5mm bore. 36tpi threaded through the displacer cylinder wall. 5mm transfer hole. Screwdriver slot in outer end......

(http://i110.photobucket.com/albums/n95/Dayjo/P1220008.jpg)



The available area/ space, now looks something like this.
With the 7mm bore ending within 5thou' of the cylinder wall, I thought sealant on the thread would squirge into the little gap, as the tube is threaded home......


(http://i110.photobucket.com/albums/n95/Dayjo/P1220004.jpg)


This is my idea for the tube.
I have an M7 x 1 tap & die. But the 5.5mm bore might leave things a bit thin.........

(http://i110.photobucket.com/albums/n95/Dayjo/P1220005.jpg)


Anyone got any good/ better ideas?

David D




Title: Re: Robinson Hot Air Engine.
Post by: Bluechip on January 22, 2011, 12:55:26 PM
Hi Dave

No good or better idea, except I have M7 x 0.75 mm pitch taps & dies ... might give a microtad or so more wall thickness. Although I don't suppose it's a lot of difference from 1 mm pitch .. welcome to a loan if you require  :thumbup:

BC
Title: Re: Robinson Hot Air Engine.
Post by: Stilldrillin on January 22, 2011, 01:02:22 PM
Hi Dave

No good or better idea, except I have M7 x 0.75 mm pitch taps & dies ... might give a microtad or so more wall thickness. Although I don't suppose it's a lot of difference from 1 mm pitch .. welcome to a loan if you require  :thumbup:

BC

Ohhh..... Dave!  :bugeye:

Didn't I always tell everyone, what a great guy you are?  :D

My t&d are out of a set from Chesterfield market. Untried/ untrusted. Yours sounds perfect.  :clap:

Yes, PLEASE!  :thumbup:

David D
Title: Re: Robinson Hot Air Engine.
Post by: Bluechip on January 22, 2011, 01:29:30 PM
Hi Dave

No good or better idea, except I have M7 x 0.75 mm pitch taps & dies ... might give a microtad or so more wall thickness. Although I don't suppose it's a lot of difference from 1 mm pitch .. welcome to a loan if you require  :thumbup:

BC

Ohhh..... Dave!  :bugeye:

Didn't I always tell everyone, what a great guy you are?  :D

My t&d are out of a set from Chesterfield market. Untried/ untrusted. Yours sounds perfect.  :clap:

Yes, PLEASE!  :thumbup:

David D

Steady on there Dave ...

Cannot deal with anything vaguely resembling recognition or adulation.  :bugeye:

Don't forget, I spent my life as a Field Techy on IT gear. Dog-hangings and b0ll0ck1ngs by the truck-load, yes. Can cope with them. No procedures in place for owt else ...  :lol: .. never been required .....

Mine are new too. Apex UK. So don't know if these work either .. ??

So, .. When and how  ?? PM your phone # if you want a natter. As it's for nowt at weekends ..

Dave BC



Title: Re: Robinson Hot Air Engine.
Post by: Stilldrillin on January 25, 2011, 03:59:04 PM
Well.....
With the amount of cast iron dust I'm producing, I should have called this posting. "Getting down n dirty with Mrs Robinson".  :D

The saga continues.
Fitted the skirt and displacer tube together..... Just a little mismatched!  :scratch:

The crescent, is the end of the displacer tube.......

(http://i110.photobucket.com/albums/n95/Dayjo/P1250004.jpg)


No wonder I couldn't get the hot cap properly centralised!  :bang: :bang:

Bored the mouth of the skirt concentric to the displacer bore......

(http://i110.photobucket.com/albums/n95/Dayjo/P1250006.jpg)


That's the new, glued in place, repair section I'm gripping on.....

(http://i110.photobucket.com/albums/n95/Dayjo/P1250009.jpg)


Great stuff, that high temp slidelock Dean! Thank you!.  :thumbup:

Drilled and started tapping, the 6off, 6BA threads holding the deck casting to the repair section. The (new) plug tap feels very stiff to turn.....  :doh:

Job stopped. Quality tap ordered, before anything goes snap....... I hate that sickening/sinking feeling!  :(

David D




Title: Re: Robinson Hot Air Engine.
Post by: Bogstandard on January 25, 2011, 04:31:19 PM
Looking real good now Dave, you'll soon be there.

You are doing the right thing by waiting for a new tap, too many get broken off down holes by people thinking they will last forever. If you have drilled the right sized hole, then it should cut fairly easily, any sign of it going tight after the fwds/bkwds motion, throw it and get a new one.


John
Title: Re: Robinson Hot Air Engine.
Post by: NickG on January 26, 2011, 06:18:54 AM
Good point John. I did the same with my BA taps and dies until the 8ba literally wouldn't cut anything! So got some soba ones for christmas from Chronos I think it was. Having said that, the 10ba tap didn't want to know on the 1/6" stainless I had though.

Nick
Title: Re: Robinson Hot Air Engine.
Post by: Stilldrillin on January 27, 2011, 12:54:50 PM
Just finished plug tapping the 6off 6BA threads, in the displacer cylinder.

The new, German made, HSS tap, "purred" as it did it's job......  (http://serve.mysmiley.net/happy/happy0163.gif) (http://www.mysmiley.net/free-animated-smileys.php)

Seems there's no substitute for quality!  :thumbup:

David D
Title: Re: Robinson Hot Air Engine.
Post by: NickG on January 28, 2011, 04:33:15 AM
David, I can testify that having had 2 BMWs and a Mini Cooper S, in my experience German made stuff does tend to purr!

Someone at work always used to say buy cheap buy twice and that motto has turned out to be correct on a few occasions - but I still don't learn my lesson!

Nick
Title: Re: Robinson Hot Air Engine.
Post by: madjackghengis on January 28, 2011, 10:51:47 AM
Hi David, I started buying my tools when I was about six, and figured out very soon, cheap tools cost more than good ones, always spend you money on the tools you will use often, with the greatest care for quality, and only ever buy a cheap tool if it is a one off job, and it's not likely the tool will break on its first job.  I have taps and dies I bought from men who retired from the tool and die trade forty and more years ago, which are still sharp and cut well, and I have a few taps which I bought new which I never got a first hole done with, and have saved only because the shank may be used to grind into a cutter some day.  I will say German tools tend to be good, but every country has tool and die makers who make and need the finest tools, so they can be had domestically, it's just a matter of knowing what quality looks like.  I try to always buy new taps in sets of three, taper, plug and bottoming, because I will always need all three if I don't, and because cheap taps don't come in anything but taper, so the sets are so far, always good quality.  Spend extra money if buying cutting tools for stainless, but you will get you money's worth, even if you spend the extra to use on aluminum or cast iron, getting a lifetime of use from them.
   On the other note, your engine is looking very good, and like it is getting very close to being a finished runner, and almost ready for video.  I'm really looking forward to seeing it run right now. :headbang: :poke: mad jack
Title: Re: Robinson Hot Air Engine.
Post by: Bogstandard on January 28, 2011, 12:29:15 PM
Much rarer to find are serial taps, where they get larger on the main cutting thread the less taper they have on the end. Arc Euro are the only cheaper, but fairly good brand that do these types of taps. It makes cutting an almost or full contact thread easier in harder materials, as you are not trying to go to full thread depth from the very beginning. Each subsequent tap of the three sizes cuts the thread a little deeper, just like you should do when using a die.

http://www.arceurotrade.co.uk/Catalogue/Cutting-Tools/Taps


But for cutting stainless, I have yet to come across any better than these.

http://www.tapdie.com/


Bogs

Title: Re: Robinson Hot Air Engine.
Post by: Stilldrillin on February 05, 2011, 09:38:27 AM


Haven't achieved a lot, this past week or so. But, I'm pretty pleased with end quality.....  :thumbup:

I planned long and hard, how to seal between displacer and cylinder.  :scratch:

Eventually, I decided to follow the previous pattern, with a threaded tube......

First, I needed the top deck fixing in alignment with the rest of the engine. Referenced the exhaust pipe.....

(http://i110.photobucket.com/albums/n95/Dayjo/P1250010.jpg)


Then aligned the deck to it, and held with a through bolt/ clamp.

(http://i110.photobucket.com/albums/n95/Dayjo/P1270012.jpg)


I then spot drilled the 6 hole pcd, through the deck.

Drilled & tapped all ok, after replacing the plug tap for a better quality one.  ::)


Found a nice piece of stainless bar. Drilled through 4.5mm. Then turned the o/d to a nice sliding fit in the brass repair tube......

(http://i110.photobucket.com/albums/n95/Dayjo/P2010001.jpg)


Used the blank to align the casting tube hole......

(http://i110.photobucket.com/albums/n95/Dayjo/P2010004.jpg)



Plunged it all the way in. Then aligned in X to a snug fit against the angle plate. (No gap, as is shown here)......

(http://i110.photobucket.com/albums/n95/Dayjo/P2010005.jpg)


Aligned in Y direction, and tightened to the angle plate. Leaving the assembly vertically in line with the m/c spindle.

(http://i110.photobucket.com/albums/n95/Dayjo/P2010007.jpg)


Made a 5mm bore drill bush, and dropped it down to rest on the cast iron displacer sleeve......

(http://i110.photobucket.com/albums/n95/Dayjo/P2010008.jpg)


Drilled through 5mm. Fished out the bush, then opened out to 6mm......

(http://i110.photobucket.com/albums/n95/Dayjo/P2010014.jpg)


Nice crisp hole......

(http://i110.photobucket.com/albums/n95/Dayjo/P2010018.jpg)



In the new section......

(http://i110.photobucket.com/albums/n95/Dayjo/P2010020.jpg)


As before, aligned in X, then Y, using a piece of 6mm bar in the drill chuck and snug in the hole......

(http://i110.photobucket.com/albums/n95/Dayjo/P2030022.jpg)


Perfect alignment for tapping, M7 x .75.......

(http://i110.photobucket.com/albums/n95/Dayjo/P2030025.jpg)


Threaded the tube, and tapped M6 in 'tother end......

(http://i110.photobucket.com/albums/n95/Dayjo/P2030029.jpg)


After all my worries over alignment of several components, and threads. It screws smoothly into place, between finger & thumb!!  :ddb: :ddb:

(http://i110.photobucket.com/albums/n95/Dayjo/P2030028.jpg)


Thinking how I it previously had a screwdriver slot, and wanting something neater looking.......

I realised I could insert and extract, with a locknut in the speed control threads!  :thumbup:

(http://i110.photobucket.com/albums/n95/Dayjo/P2030030.jpg)


Just a bit pleased.....  :D

Hope the euphoria lasts...... Can't see much being done next week! ::)

David D

Title: Re: Robinson Hot Air Engine.
Post by: NickG on February 05, 2011, 11:16:56 AM
Not surprised, it's looking a top quality job - well done  :thumbup:
Title: Re: Robinson Hot Air Engine.
Post by: madjackghengis on February 05, 2011, 11:22:24 AM
Well.....
With the amount of cast iron dust I'm producing, I should have called this posting. "Getting down n dirty with Mrs Robinson".  :D

The saga continues.
Fitted the skirt and displacer tube together..... Just a little mismatched!  :scratch:

The crescent, is the end of the displacer tube.......

(http://i110.photobucket.com/albums/n95/Dayjo/P1250004.jpg)


No wonder I couldn't get the hot cap properly centralised!  :bang: :bang:

Bored the mouth of the skirt concentric to the displacer bore......

(http://i110.photobucket.com/albums/n95/Dayjo/P1250006.jpg)


That's the new, glued in place, repair section I'm gripping on.....

(http://i110.photobucket.com/albums/n95/Dayjo/P1250009.jpg)


Great stuff, that high temp slidelock Dean! Thank you!.  :thumbup:

Drilled and started tapping, the 6off, 6BA threads holding the deck casting to the repair section. The (new) plug tap feels very stiff to turn.....  :doh:

Job stopped. Quality tap ordered, before anything goes snap....... I hate that sickening/sinking feeling!  :(

David D


I was just thinking, "with the amount of cast iron dust I'm creating", maybe you should be collecting it, and then put it all in a little dam and with an oxy-acetalene torch, melt it down into a new foot. By the way, that fix on the air tube, sealing out the water looks like it should do a fine job and make that engine run. Just a thought :lol: :poke: mad jack




Title: Re: Robinson Hot Air Engine.
Post by: sbwhart on February 05, 2011, 12:10:44 PM
Give that man a coconut:-  :thumbup:  :clap: :clap: :clap: :clap:

Looking real nice Dave.

Ther's a nice pic in latest issue of model engineer of a robson hot air engine that was made in 1900 and used for turning roasting Coffee.

Ther's also a nice picture of a three cylinder radial engine on the front cover

  :D :D :D :D

Stew
Title: Re: Robinson Hot Air Engine.
Post by: NickG on February 05, 2011, 03:26:54 PM
Stew, I've been looking out for your articles, will have to have a look - might even buy it!  :beer:
Title: Re: Robinson Hot Air Engine.
Post by: arnoldb on February 05, 2011, 03:52:52 PM
Really nice job David  :thumbup: - Well done!

 :beer:, Arnold
Title: Re: Robinson Hot Air Engine.
Post by: shoey51 on February 05, 2011, 04:15:12 PM
 :bow: David im really impressed with ingenuity wish I had it :scratch:

keep up the great work mate 
Title: Re: Robinson Hot Air Engine.
Post by: Dean W on February 05, 2011, 07:53:11 PM
David, what a nice clean job!  Excellent use of that bushing for drilling the hole in the bottom of the..  hole.  : )
You do good work.
Title: Re: Robinson Hot Air Engine.
Post by: Stilldrillin on February 06, 2011, 04:06:28 AM
Thanks for all your positive comments Chaps!  :thumbup:

They're really appreciated, especially after some planning/ machining has gone right......  :ddb:

Stew. I've got to get meself a copy of Model Engineer.  :D

David D
Title: Re: Robinson Hot Air Engine.
Post by: Stilldrillin on February 08, 2011, 06:41:31 AM
Just measuring up. Before sorting the wobbly displacer piston......

(http://i110.photobucket.com/albums/n95/Dayjo/P2080004.jpg)


Is there any reason for the displacer to have .2" clearance at the bottom, (hot end) of it's stroke. And "nil" clearance at the top, (cold end)?  :scratch:

I can easily extend the shaft by .1", to make both clearances the same.  :thumbup:

David D
Title: Re: Robinson Hot Air Engine.
Post by: NickG on February 08, 2011, 08:07:58 AM
Do that David, it's quite a bit of clearance though 0.1". What is the clearance around the displacer piston? The hot air engine that I made I think I gave 1/32" all around and at each end.

The clearance should be minimal but also enough so that it doesn't cause any sort of drag when squeezing the air from one end to the other.  :thumbup:

Nick
Title: Re: Robinson Hot Air Engine.
Post by: Stilldrillin on February 08, 2011, 08:20:59 AM
Nick.
There's around .08" difference, between slightly distorted displacer, and the cylinder. (.040"/ side).

2.25" bore x .75" stroke.

David D
Title: Re: Robinson Hot Air Engine.
Post by: Dean W on February 08, 2011, 06:40:48 PM
Nick.
There's around .08" difference, between slightly distorted displacer, and the cylinder. (.040"/ side).

2.25" bore x .75" stroke.

David D

David, that clearance (0.040") sounds okay, considering how large the displacer piston is.  I'll (dis)-qualify that by saying
I have not built this particular stirling design, but on others the displacer fairly flops around in there.  The last one I built
had near .020"/ side on a 3/4" diameter piston.
For the distance between piston at the top and bottom, the ones I've built have been quite close at the end of
each stroke.  I would think splitting the top and bottom clearance would be appropriate. 
Title: Re: Robinson Hot Air Engine.
Post by: NickG on February 08, 2011, 06:49:09 PM
Was just going to say the same as Dean, that's a relatively small gap so will be fine. You just aim for the least dead space possible but it will be fine.  :thumbup:

Nick

Title: Re: Robinson Hot Air Engine.
Post by: Stilldrillin on February 09, 2011, 04:17:43 AM
Thanks for your replies, Chaps!  :thumbup:

I wondered if it was some sort of tuning bias. Rather than another builder's bodge......  ::)

The pot is in sound condition. I will be able to turn a new top/ shaft location, to repair nicely. Probably.....   :D

David D
Title: Re: Robinson Hot Air Engine.
Post by: madjackghengis on February 10, 2011, 12:04:54 PM
Well David, it looks really good so far, and like you should have it running up to snuff shortly.  I'm really looking forward to seeing that video of it running, and maybe doing something useful, like pulling the cat's tail or some other good domestic job.  :lol:  :beer: cheers,
mad jack
Title: Re: Robinson Hot Air Engine.
Post by: Stilldrillin on April 18, 2011, 03:39:37 PM


The pot is in sound condition. I will be able to turn a new top/ shaft location, to repair nicely. Probably.....   :D

David D

Ah! Well........ They were prophetic words!   ::)

As you now know, everything stopped with a bang.  :bang: ...... Well, more of a clatter from the machine, and a whimper from me.......  :bang: :bang:


(http://i110.photobucket.com/albums/n95/Dayjo/P2110007.jpg)


So, I sulked for a while.
Thought about making my own design.....  :scratch:

No!...... I want to keep it standard. So, I'll just buy another pot, and work from there. But not really in my comfort zone.....

I contacted Polly Models via email, explaining I needed a displacer pot/ cup. The reply was, "A replacement displacer is 18.00 inc vat plus postage of 3.00"....... Hmmm..... Ok, then......

This is what arrived! Which I would call a hot cap........

(http://i110.photobucket.com/albums/n95/Dayjo/P2280022.jpg)


Twice the thickness of brass, (.045", rather than .022"). 'Orribly big, dead space radius. Wouldn't fit in place of my hot cap.......

(http://i110.photobucket.com/albums/n95/Dayjo/P2280021.jpg)


So, I contacted Poll Models, and was told this best fitted my description of a displacer pot/ cup!!  :bugeye: .......  Hmmm.....

Didn't like to argue with a lady. So, I asked for an exchange for the displacer, as named on the invoice......

This arrived...... After I had paid to return the hot cap, and after I had paid another 3 for their postage to me......

(http://i110.photobucket.com/albums/n95/Dayjo/P4170020.jpg)

Looks ok.... Dunnit!


(http://i110.photobucket.com/albums/n95/Dayjo/P4170021.jpg)


Only, it's twice the original material thickness, and larger diameter.........   ::)

(http://i110.photobucket.com/albums/n95/Dayjo/P4170023.jpg)


The working clearance is/ would be .020"! And obviously, I can't bore out my hot cap to match!

27, for a displacer pot, I can't use!  :bang: :bang: :bang:



So, I put it away....... And went and did a few other things, for a couple of months!

Normal fumblings will be resumed in a few weeks. Probably!  :thumbup:

David D
Title: Re: Robinson Hot Air Engine.
Post by: sbwhart on April 18, 2011, 03:54:16 PM
That's a bummer Dave  :(

How about bushing the bore to get a fit  :scratch: .

Stew
Title: Re: Robinson Hot Air Engine.
Post by: HS93 on April 18, 2011, 06:43:21 PM
is the old one beyond repair? I know it looks bad but woith a bit of taping hear and there I have seen worse.   :dremel:

Peter
Title: Re: Robinson Hot Air Engine.
Post by: Dean W on April 18, 2011, 07:13:49 PM
Glad to see an update, David, but not your troubles getting a simple part!  I think you could fix the old one, too.
A bit of bashing and a few spots hard soldered to fill the holes and... original part back in service.  The small dents and
dings shouldn't matter to the displacer can, since it fairly flops around in the hot cap anyway.  Not like it has to be
a close fit.
Good luck how ever you do it.  Hope it doesn't keep you away from this project for another two months!  ; )

Dean
Title: Re: Robinson Hot Air Engine.
Post by: madjackghengis on April 18, 2011, 09:37:54 PM
Well David, call me a cynic, but can you take about half the thickness off the displacer, and gain it as clearance, and get enough to make it run? Jack
Title: Re: Robinson Hot Air Engine.
Post by: Stilldrillin on April 19, 2011, 02:09:11 AM
Thanks for your replies Chaps!

Stew.
Not sure as I understand "bushing" for fit.... The displacer spinning is oversize to my bore and cap. Only .02" clearance....
I think it should be around .1"....... Unless anyone else has an opinion on what the clearance should be? :scratch:

Jack.
Frankly, it's slightly tapered, and skimming would only release around another .02", giving .04".... Hardly enough, probably!

Peter, Dean.
Looking at it, now.... Yes! You're right. I could probably knock it into some semblance of original shape......

Fortunately..... After my, "blunders you make?", posting....... I had a pm from a Gentleman of this Parish, offering to make one for me.......  :thumbup:

I now have to decide on sizes, and produce a drawing..... Does anyone have any objections to .1" clearance, o/d and .05" clearance either end?

Or, any other comments?  :wave:

David D
Title: Re: Robinson Hot Air Engine.
Post by: sbwhart on April 19, 2011, 03:22:24 AM

Stew.
Not sure as I understand "bushing" for fit.... The displacer spinning is oversize to my bore and cap. Only .02" clearance....
I think it should be around .1"....... Unless anyone else has an opinion on what the clearance should be? :scratch:

David D


Nither do I  :lol: sorry misunderstood how it worked  :hammer:

Stew
Title: Re: Robinson Hot Air Engine.
Post by: Stilldrillin on May 15, 2011, 10:03:11 AM
Well..... Here we go again!  ::)

Unfortunately, shop time is a bit restricted these days. I have to grab what I can, when I can......

As you all know, Gentleman John supplied a new, superb displacer piston.....

(http://i110.photobucket.com/albums/n95/Dayjo/P5090013.jpg)


Assemble with displacer and linkage at bdc. Mark the hole position......

(http://i110.photobucket.com/albums/n95/Dayjo/P5130006.jpg)


Rotate to tdc. Piece of paper towel holding displacer at tdc. Mark hole position......

(http://i110.photobucket.com/albums/n95/Dayjo/P5130008-1.jpg)


This gave two marks, 5mm apart. Drill pin hole central, to give 2.5mm clearance at each end of stroke.

Then assemble with piston and rod. Shorten shaft to just clear underside of conrod. (Tiny chink of light showing)......

(http://i110.photobucket.com/albums/n95/Dayjo/P5130011.jpg)


Orientated the cylinder and bearing  pedestal square to each other, and drilled for 1/8" dowels.

The air transfer hole was some distance off tube centre. It took a 10mm recess to clean up.

Drilled through 5mm.......

(http://i110.photobucket.com/albums/n95/Dayjo/P5090006.jpg)


Machined a brass bush......

(http://i110.photobucket.com/albums/n95/Dayjo/P5090009.jpg)


Sleevelocked into place to make a recess for an O ring......

(http://i110.photobucket.com/albums/n95/Dayjo/P5090012.jpg)


Every internal area which had been rusty, had a coat of Hammerite.....

(http://i110.photobucket.com/albums/n95/Dayjo/P5120016.jpg)


Including inner end of the cylinder, and piston crown.......

(http://i110.photobucket.com/albums/n95/Dayjo/P5130004.jpg)


Assembled with new hot cap gasket, and Hylomar.......






More twiddling and fiddling to come. Water test to come next! Hmmmm.........

David D


Title: Re: Robinson Hot Air Engine.
Post by: saw on May 15, 2011, 10:41:38 AM
Nice  :clap: :clap:
Title: Re: Robinson Hot Air Engine.
Post by: sbwhart on May 15, 2011, 11:52:13 AM
Well done Dave a sweet runner  :thumbup: :clap: :clap: :clap: :clap: :clap: :thumbup:

Stew
Title: Re: Robinson Hot Air Engine.
Post by: Bluechip on May 15, 2011, 12:10:29 PM
 :bow:  :bow:  :bow:

It's a good 'un ....  :thumbup:

Not before time though, ... been holding my breath on this one. Turning blue in the face here ...

Well worth the wait.

Dave BC
Title: Re: Robinson Hot Air Engine.
Post by: Stilldrillin on May 15, 2011, 12:15:12 PM
Thanks Chaps!  :thumbup:

Dave. You should know me by now...... Occasionally, round tuits and orphans get in the way.......  :D

David D

Title: Re: Robinson Hot Air Engine.
Post by: Bogstandard on May 15, 2011, 12:53:54 PM
David,

My anal sphincter has been twitching, ever since that piston had been made, just in case I had made a booboo somewhere.

It now looks to be OK then, so I can stop sweating.

What a lovely running engine, now that you have waved your magic fingers over it, and finally brought it back from the dead. :bow: :bow: :med: :med:


Wonderful job and write up, thanks for the experience. :clap: :clap:  :thumbup: :thumbup:


John

Title: Re: Robinson Hot Air Engine.
Post by: Rob.Wilson on May 15, 2011, 03:00:46 PM
 :ddb: :ddb: :ddb: :ddb: :ddb: :ddb:  Nice one David  :D :D :D :thumbup:


Rob
Title: Re: Robinson Hot Air Engine.
Post by: arnoldb on May 15, 2011, 03:12:20 PM
Nice one David  :thumbup: - runs like a Champ   :clap: :clap: :clap:; Well done indeed!

 :offtopic:  What kind of bird was that singing in the background on the video? - Had my parrot sitting with me while looking at the vid and he started by imitating the engine; he does that, but when the bird started to tweet he went quiet and just sat there listening...  I have a hunch he'll be practising it : ) - and it's a really nice bird call : )

Kind regards, Arnold
Title: Re: Robinson Hot Air Engine.
Post by: Stilldrillin on May 15, 2011, 03:41:17 PM
Thanks for kind words Chaps..... And all your help and encouragement throughout this saga!   :thumbup:

Arnold, that is one of the 5 or so, male blackbirds, who compete for territory and females at this time of year. One of them is singing his socks off, on my chimney at the moment......
They all sing beautifully...... Each with his own repertoire.  :)

David D
Title: Re: Robinson Hot Air Engine.
Post by: Dean W on May 15, 2011, 03:59:32 PM
"Short little prayer"...
Must have had something to do with a lot of work too, David.  Look at that!  A fine runner!
Congrats!

Dean
Title: Re: Robinson Hot Air Engine.
Post by: doubleboost on May 15, 2011, 04:11:14 PM
What a nice noise it makes :D :D :) :)
Well done :bow: :bow:
John
Title: Re: Robinson Hot Air Engine.
Post by: Stilldrillin on May 17, 2011, 03:51:22 AM
"Getting Down and Dirty with Mrs. Robinson"....... The finale.

This is the last instalment of this long saga.....

Her present condition is now as I hoped it would be, when she came to me as an orphan, almost 9 months ago.....  ::)



She ran faultlessly yesterday, for almost an hour.......  :D






Work left to do, is mostly cosmetic. Replace temporary link pins. Mend broken foot. Sort speed control screw. Tidy up castings, and paint.

Oh! And replace lathe motor, which hasn't been happy since machining the 2lb weight into a displacer sleeve.
When standing idle yesterday, it suddenly started up! Full revs, in reverse! Then stopped with a big flash/ pop!   :palm:

Sigh .... There's allus summat needing attention......  :bang:

Thanks, to everyone, for all your great help and support. More of similar to come, in the future. :thumbup:
(Incidentally, hasn't anyone spotted the latest little waif, in the last video)?  :scratch:

David D
Title: Re: Robinson Hot Air Engine.
Post by: HS93 on May 17, 2011, 04:18:33 AM
looks good Dave been following your re build,
sorry to hear about lathe what motor was it.?

Peter
Title: Re: Robinson Hot Air Engine.
Post by: saw on May 17, 2011, 04:59:15 AM
Nice rebuild  :clap: :clap: :thumbup:
Title: Re: Robinson Hot Air Engine.
Post by: Dean W on May 17, 2011, 06:13:24 PM
Now fully "aquafied" and running beautifully well.  I love how calmly it seems to run.  Fun to watch!
Again, good job David!
Title: Re: Robinson Hot Air Engine.
Post by: stirling lad on May 18, 2011, 10:08:29 PM
Well done David, :clap: she sounds devine....was that a brassy robinson sister in the back ground in your last vid ? :bugeye:
 
where do you find em? :drool:


   ...Mike..