Author Topic: Rocking Engines (Read 28781 times)

sbwhart · « **on:** July 12, 2009, 03:28:22 PM »

When I was skiming through the John Tom drawings I saw the rocking engine

and thought it was a osilating engine and passed it by, the name intreged me so a few days later I went back for another look, that,s when I got another dose of

its small size suites the type of work I like doing and it looked like It could be a weekend project, and as I'm going to retire in two weeks I thought it would make a nice presents for couple of work friends.

It's also a good delaying tactic to avoid assembling the loco, perhaps it would boost my enthuseasm.

These are the drawings
http://www.john-tom.com/MyPlans/SteamPlans3/RockingSteamEngine/ROCKING%20STEAM%20ENGINEs.pdf

Any of you chaps made this engine ?

I'm a great beliver that its just as easy to make two of something

First job do all the turning bits.

I made the two cylinders together to speed up the work, turned the OD of the cylinders to the size of the square diagonal, put a groove to show where the join would be, and used a 3/8" end mill to finish off the flat bottom hole.

To mill the square set up in vice touch down on the job set DRO to zero mill off 1/2 the difference of the diameter and across flat size you want zero DRO, flip it over 90 deg with the flat against the vice jaw mill down to zero flip it over 90, mill off the remaining difference zero dro, flip it over finish off other side you've got a square.

To mill out the pocket for the crank I used a long reach 1/8 slot drill set the job up in the mill with the vice stop, milled the first pocket out zeroing everything up, turned it round and making sure it was up against the stop and milled the seconf pocket working up to the zeros, the same routine was done for the crank and stand holes.

For the flywheel turned down the bar to size then transfered them over to the RT in the mill and drilled the spoke holes deep enough to make two fly wheels.

This is one engine finished off with the second waiting for the flywheel

Does it work

NO

If you look at the photo showing the finished engine it sitting on a pad with a lot of figures on it, what this is about is for some reason the piston was bottoming in the cylinder, a quick measure and a calculation and yes I'd drilled them wrong

I'll just have to make again.

Slightly frustrated

Stew

bogstandard · « **Reply #1 on:** July 12, 2009, 03:38:01 PM »

Stew,

Does measure twice, cut once spring to mind.

A real bummer, but actually I wasted some time today, making a couple of bits. But it wasn't my fault. You will need to read the post on the little engine I am restoring, when eventually it is posted.

So you are not alone.

HEADLINES

The sky falls on Crewe, two machinists in a bad mood and brassed off.

Bogs

sbwhart · « **Reply #2 on:** July 12, 2009, 04:01:04 PM »

Hi John

It must be something in the water.

You've got to laugh.

Stew

raynerd · « **Reply #3 on:** July 12, 2009, 04:33:32 PM »

Looks like a nice little engine and not all the parts are wasted right? Post us some pictures when you re-do it and get it running....

Chris

Stilldrillin · « **Reply #4 on:** July 13, 2009, 02:26:53 AM »

Oh, BUGGA!!!

But, they do look really nice & purposeful......

David D

NickG · « **Reply #5 on:** July 13, 2009, 07:18:04 AM »

Oh dear! How does it work Stew? Don't understand it!

sbwhart · « **Reply #6 on:** July 13, 2009, 07:37:30 AM »

Quote from: NickG on July 13, 2009, 07:18:04 AM

Oh dear! How does it work Stew? Don't understand it!

Neather do I thats why I've made one

The crank shaft centre line is set above the cylinder centre line, so that when its on the return stroke the piston rocks back and acts like a clack valve when it reaches bottom dead centre the crank pin lines up with cylinder centre line and the piston seals the bore and you get a power stroke, hope this makes sence, havn't got one working yet:- it looks an improbable system doesn't it

Stew

raynerd · « **Reply #7 on:** July 13, 2009, 08:16:01 AM »

Nice little animation of how it should work here:

Stilldrillin · « **Reply #8 on:** July 13, 2009, 08:20:53 AM »

Is it me?

It`s running backwards.......
That`s a pump, innit?

David D

raynerd · « **Reply #9 on:** July 13, 2009, 09:23:11 AM »

Yea, I see what you mean. If it was to be correct then the piston is going to be moving into the cylinder when it is sealed

Should the piston be moving into the cylinder at an angle so that any pressure is released around the sides? I`m just trying to get my head around how that works. There must still be a fair force acting against the piston through its return stroke even if air/steam is escaping around its sides.

Hope you get it working Stew, then we can see how it runs for real.

Chris

sbwhart · « **Reply #10 on:** July 13, 2009, 09:30:44 AM »

Hi Chaps

It is a bit of a quere beast init,

now you can see why I got

just to see if it would work, it'l be a couple of days before I get any quality shop time before I can have a go at fixing it.

I've asked on another forum if anyones made one, as yet its been a negitive.

Stew

NickG · « **Reply #11 on:** July 13, 2009, 09:54:49 AM »

Sounds weird but innovative. I kind of get it, can't see the animation here though! Might have to draw it up on CAD to see!

Nick

bogstandard · « **Reply #12 on:** July 13, 2009, 11:13:30 AM »

Dave is quite right, he has got the animation upside down on the piston movement.

It should be tilted as it goes into the cylinder and square on as it is coming out.

Bogs

rleete · « **Reply #13 on:** July 13, 2009, 11:14:30 AM »

I was just now given some brass screws (1/4-20 pan head) which are a perfect size to turn down for the piston. I think I'll have a go at this, just for grins.

Stilldrillin · « **Reply #14 on:** July 13, 2009, 12:37:20 PM »

This took some finding!

I`m sure Indiana Rog won`t mind sharing with us.....

He has 3 of them!

http://www.indianarog.com/lineymachineengines.htm#255440530

David D

raynerd · « **Reply #15 on:** July 13, 2009, 01:15:13 PM »

Nice find and nice engine - good luck Stew. The plans for this one have been filed away!.

Chris

sbwhart · « **Reply #16 on:** July 13, 2009, 03:28:15 PM »

Chris and David D

Thanks for taking the trouble to find the animation and video and sharing, at least we know that they run all we've got to do is prove it to ourselves.

Have fun

Stew

DavesWimshurst · « **Reply #17 on:** July 13, 2009, 09:26:35 PM »

Stew,
Here is a video I found a while ago on some engines and compressors using the same type piston:

&feature=poptnjrf4a

It took me a while to find it again but your build reminded me I'd seen it somewhere.
The exaggerated claims sound flaky of course

Dave

NickG · « **Reply #18 on:** July 14, 2009, 06:26:59 AM »

Just had a closer look at the drawings - I like it! Will give this one a go when get my workshop sorted.

You got one working yet Stew?

bogstandard · « **Reply #19 on:** July 14, 2009, 07:36:48 AM »

I think you have hit it on the head Dave,

That chappie is a bit full of it for his own good, and is talking out of the wrong end most of the time.

Within a minute of starting, he is giving out false information about steam engine design, and he has no grasp of efficiencies, power input and output, etc. at all.

I could get a cruise liner generator to light up a small bulb, but try doing the same thing with two burning blades of grass.

John

sbwhart · « **Reply #20 on:** July 14, 2009, 02:59:14 PM »

Quote from: NickG on July 14, 2009, 06:26:59 AM

Just had a closer look at the drawings - I like it! Will give this one a go when get my workshop sorted.

You got one working yet Stew?

Hi Nick

Been up at Ridsdale saying my good buys to the chaps, so not had any shop time, tomorrow night I'm going to give it a good go.

Stew

Divided he ad · « **Reply #21 on:** July 14, 2009, 03:04:56 PM »

Ok.... So this is just annoying!!

I'm going to have to add this little beauty to my to do list!

After seeing all of those videos thanks to David D I'm really going to have to have a go at at least one!!!

Looking good Stew...... Drilling to the wrong depth..... What'd be easier..... re-making the piston/con rod or the cylinder?

I'm sure it'd work with a shorter stroke?

Now sitting here re-designing the exterior of the engine I haven't yet seen the plans for

..... BLING!

Ralph.

John Hill · « **Reply #22 on:** July 14, 2009, 08:35:47 PM »

OK, colour me dumb!!!

I can see how the piston 'opens' and closes to get the required exhaust valve effect but what happens on the inlet? Is all just being wasted while the piston is on the way 'up'?

bogstandard · « **Reply #23 on:** July 14, 2009, 10:25:46 PM »

You got it in one John, unless there is a poppet valve arrangement in the head to only allow it to 'fire' when the piston reaches TDC. That was what the goon was showing in the little plastic engine in the vid that Dave provided. Otherwise it is a continuous pressure feed that the engine only uses when on the power stroke. Half used, half wasted.

John

John Hill · « **Reply #24 on:** July 14, 2009, 10:42:54 PM »

Ah, thanks John, still it is a neat enough little engine in a tiny size and one that runs so fast you would not notice air escaping 'tween strokes.

NickG · « **Reply #25 on:** July 15, 2009, 07:13:48 AM »

John,

I made an oscillator with 1/4" bore and about 3/4" stroke with a slight design floor, at 90 degrees before TDC when exhausting the with of the cylinder wasn't big enough to cover the inlet port so there is momentarily an air leak and you can actually hear it, even when running at speed! It uses a lot more air than an engine of that size should too!

Nick

sbwhart · « **Reply #26 on:** July 15, 2009, 02:11:03 PM »

Hi Chaps

Well I made a new piston and fitted it all together

AND

ITS A RUNNER
But

It'll only run upside down

What I've found that it ony needs a whisper of air any more and it just locks up in the forward position.

To get it running correct way up I think I need a better fit in the bearing, also the contact area on the bearing is only small so I'm thinking I may change the design to increase the contact area so you get a better fit without slop.

Also took a video but I can't get it to play my machine use to open the up as microsoft media player but for some reason its taken it in its head to open them a nero don't know why

but it wont run now.

What with upside down running engines and computers with an invisable hand lifes getting spooky.

Fealing strange

Stew

Stilldrillin · « **Reply #27 on:** July 15, 2009, 02:20:27 PM »

Stew,

Well done (so far) with the Aussie engine!

"Fealing strange" ??

You wait a while into retirement, then the whole world will feel strange. BUT you`ll be used to it by then......

David D

raynerd · « **Reply #28 on:** July 15, 2009, 03:56:35 PM »

Get the camera back out Stew when you get a chance - would like to see it running upside down or not! Keep us informed.

Chris

rleete · « **Reply #29 on:** July 15, 2009, 04:19:52 PM »

Quote from: sbwhart on July 15, 2009, 02:11:03 PM

also the contact area on the bearing is only small so I'm thinking I may change the design to increase the contact area so you get a better fit without slop.

Did you press fit the sleeve (the .188 diameter tube) into the cylinder/frame part? I think that's how it's supposed to work (and how I am making mine) so that you get the full length of that sleeve as a bearing surface. No instructions along with the plans, and not even any tolerances specified, so it's not completely clear how it is supposed to go together. I'll have to have another look at the plans.

sbwhart · « **Reply #30 on:** July 15, 2009, 05:04:49 PM »

Quote from: rleete on July 15, 2009, 04:19:52 PM

Quote from: sbwhart on July 15, 2009, 02:11:03 PM
also the contact area on the bearing is only small so I'm thinking I may change the design to increase the contact area so you get a better fit without slop.

Did you press fit the sleeve (the .188 diameter tube) into the cylinder/frame part? I think that's how it's supposed to work (and how I am making mine) so that you get the full length of that sleeve as a bearing surface. No instructions along with the plans, and not even any tolerances specified, so it's not completely clear how it is supposed to go together. I'll have to have another look at the plans.

No I didn't press fit the sleeve in, but thats how I was going to change the design I'm planning to sweat the sleeve in with soft solder.

I think we have a case of great minds thinking alike here

.

Thanks for your input and suggestion, its a real nice sweat running engine even though its upside down because of the low air pressure it ticks over lovely with puff puff puff and you can see the action, really worth the effort of making one.

Thanks again

Stew

NickG · « **Reply #31 on:** July 16, 2009, 05:05:53 AM »

Well done Stew!

The only thing is, you do these little fill in projects too quickly!!! You can't put off the frame assembly any more now ahaha!

rleete · « **Reply #32 on:** July 18, 2009, 12:39:25 AM »

Stew, may I ask how long it took you to make the parts? The reason I ask, is because I'm making the same engine - with a few of my own touches.

I'd like to know just how fast some of you guys can whip out parts.

sbwhart · « **Reply #33 on:** July 18, 2009, 01:39:15 AM »

Quote from: rleete on July 18, 2009, 12:39:25 AM

Stew, may I ask how long it took you to make the parts? The reason I ask, is because I'm making the same engine - with a few of my own touches.

I'd like to know just how fast some of you guys can whip out parts.

To make all the bits for two engines it took me about 6 hours, I've been playing around trying to get them to run and to remake bits about the same length of time I've still got a couple of hours more work to do over this week end to get them running the right way up.

Hope this helps

Stew

foozer · « **Reply #34 on:** July 18, 2009, 02:42:57 AM »

Quote from: sbwhart on July 18, 2009, 01:39:15 AM

Quote from: rleete on July 18, 2009, 12:39:25 AM
Stew, may I ask how long it took you to make the parts? The reason I ask, is because I'm making the same engine - with a few of my own touches.

I'd like to know just how fast some of you guys can whip out parts.

To make all the bits for two engines it took me about 6 hours, I've been playing around trying to get them to run and to remake bits about the same length of time I've still got a couple of hours more work to do over this week end to get them running the right way up.

Hope this helps

Stew

Made two pieces so far for a rocker, machine time about 22 minutes (timer left over from the treadmill motor mod) Time spent in barn? good thing I'm retired and dont watch the clock

sbwhart · « **Reply #35 on:** July 18, 2009, 06:24:58 AM »

Well got the little gem running right way up, not without a bit of trama, any way a little up date.

As you know I had a bit of trouble getting the piston crank drilled in the correct position so what I did is make a little drilling aid, it was a simple bush that I slipped the con rod through to grip the piston for drilling I was then able to pick the edge of the vice up and Zero my dials and index to the correct position for drilling, worked like a dream.

This is the bush with a piston in place

And this is it in use

Then instead of a lose bush thing that the drawing shows I made a bearing with a 4mm hole and shouldered to fit into the cylinder, I soft soldered this in place using solder paste, great stuff this for little jobs

Turned down the spindle for a nice fit in this bearing.

At first when I assembled it together it still wouldn't run right way up but it fiddled with it a bit tried a tighter fitting piston this didn't work, I'd gaven it a good oiling so stripped it down cleaned all this oil off and tried running it dry and away she went right way up wrong way up any way which.

And as

I'm down loading a vid from my lap top onto youtube its taking an age and I'm running out of time Boss wants some of my time so you'll have to wait for it

Stew

sbwhart · « **Reply #36 on:** July 18, 2009, 06:38:06 AM »

The Move

Do you like the exit stage left

Realy having fun

Stew

Andy · « **Reply #37 on:** July 18, 2009, 08:40:00 AM »

It makes a great sound. Really like that.

Stilldrillin · « **Reply #38 on:** July 18, 2009, 11:23:21 AM »

Well done Stew! That`s a crackin` little engine!

It`s got a nice sound to it.....

Classic exit!

David D

foozer · « **Reply #39 on:** July 18, 2009, 11:33:39 AM »

Quote from: sbwhart on July 18, 2009, 06:24:58 AM

Then instead of a lose bush thing that the drawing shows I made a bearing with a 4mm hole and shouldered to fit into the cylinder, I soft soldered this in place using solder paste, great stuff this for little jobs

Stew

Solves one issue. Even with a press fit not a lot of meat to secure the bushing. Solder, ah yes, but yet another opportunity to muck things up.

Good Job

Robert

Darren · « **Reply #40 on:** July 18, 2009, 02:09:08 PM »

Brilliant Stew, they look like cracking little engines....

sbwhart · « **Reply #41 on:** July 18, 2009, 06:13:26 PM »

Thanks Chaps just got to get No 2 running tomorrow, they've been an enjoyable little engine to build and they are a joy to watch and hear run.

I'm all eager to start and put that Loco together now

Cheers

Stew

Divided he ad · « **Reply #42 on:** July 19, 2009, 10:42:20 AM »

Right.... Now I'm going to have to make one!!

Nice little machine there Stew.... Hopefully #2 is as good a runner?

Back to the loco.... Video next weekend?

.... Well you got to say it really

Ralph.

Bernd · « **Reply #43 on:** July 19, 2009, 07:58:07 PM »

Nice job Stew. like that sound too.

Bernd

sbwhart · « **Reply #44 on:** July 20, 2009, 01:23:23 AM »

Well got Rocky 2 running and its better than Rocky 1 gave it a blast of WD40 it doesn't seem to be pressure sensitive wound the it up to max and it fairly bussed along. Took a vid of both running then spent the whole of last night trying to down load it on youtube it would get part way through then fall over,

any one else had this problem is it band width or the demand on the server

Have fun

Stew

raynerd · « **Reply #45 on:** July 20, 2009, 02:36:45 AM »

Hey Stew, sorry but I must have missed this a couple of days ago! Great news that you have finished it and the sound it makes is amazing. I am certainly going to have a go at one of these.

Regarding youtube - if your on broadband it really should be timing out! How big is the vid?

Chris

sbwhart · « **Reply #46 on:** July 20, 2009, 03:10:41 AM »

Quote from: craynerd on July 20, 2009, 02:36:45 AM

Regarding youtube - if your on broadband it really should be timing out! How big is the vid?

Chris

Never thought of time it is a bit of an epic, I'll try shortening run time.

Thanks for the suggestion

Stew

NickG · « **Reply #47 on:** July 20, 2009, 04:38:10 AM »

Stew,

I haven't seen the video yet but well done, keep picking up lots of tips and tricks from you! I have a pot of that solder paste and it is brilliant, I use it as a flux more than anything, I always feel the need to feed a bit more solder in for good measure!

Nick

Stilldrillin · « **Reply #48 on:** July 20, 2009, 08:05:44 AM »

Quote from: NickG on July 20, 2009, 04:38:10 AM

Stew,

I haven't seen the video yet but well done, keep picking up lots of tips and tricks from you! I have a pot of that solder paste and it is brilliant, I use it as a flux more than anything, I always feel the need to feed a bit more solder in for good measure!

Nick

Ok Chaps!

Where do I get some of this posh pastey solder stuff?

I usually bung up me little steampipes, with too much solder.......

David D

sbwhart · « **Reply #49 on:** July 20, 2009, 08:13:35 AM »

I got mine from Blackgates engineering

www.blackgates.co.uk

Its real nice stuff to use as you put a lot on and it seams to shrink when you heat it up, your just left with a slight film thats dead easy to clean up. It seams to work ok without flux as the solder is in a solution of flux already.

Hope this helps

Stew

sbwhart · « **Reply #50 on:** July 20, 2009, 03:51:24 PM »

Hi Chaps

I'd just like to say a big thanks for you're comments and joining in, isn't the net wonderful for bringing people together, and a big thanks to you guys who run sites like this.

I've been trying for the last two days to download a vid of the two engines running together but I keep losing the link I've tried shortening vid time, loading via a PC and a mac but no good so I'm giving up that particular quest.

So I'd thought I'd show you my rocker scrap

OK I've showed you mine now you show me yours

Have fun

Stew

Stilldrillin · « **Reply #51 on:** July 21, 2009, 02:02:18 AM »

I decided a while ago, NO engine building until I`ve sorted all other projects.......

Why have I printed the drawings?

Why have I sorted some brass stock?

No scrap to show Stew....... Yet!

David D

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Author Topic: Rocking Engines (Read 28781 times)

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