Author Topic: The Rainbows Engine....... (Read 17277 times)

Stilldrillin · « **on:** February 22, 2014, 03:31:32 AM »

Every year, members of my other forum have a charity steam up, at Eastwood in Nottingham. Near to Junction 26 of the M1 motorway.

Hence..... The J26 Steamup. On behalf of the Rainbows Children's Hospice.

Last year, we made over £2,500.

Presentation day.......

At the end of the day, this orphan was left on my table.

It will be recycled, then auctioned on forum.........

I believe it has traveled all the way from Australia. Then had a little adventure here. Before finally coming to me.........

Stripped.........

Another poorly designed Seig engine. Unfortunately, there are a few things, not right.

The aftermarket perspex base holds the burner in the wrong position.
The displacer is too short, compared to the swept volume of the hot cap.
The ratio between pistons is only 1.15.

I'm thinking of enlarging the displacer volume, this time. As opposed to (usually) sleeving down the power cylinder.

Hopefully, there will be steady progress. As and when, I can get comfortable workshop time........

David D

Manxmodder · « **Reply #1 on:** February 22, 2014, 10:59:13 AM »

David, this looks like it will be an interesting thread.

I will be watching your progress with interest and hopefully learn a thing or 2 for the day when I get round to build my first hot air engine.......OZ.

Stilldrillin · « **Reply #2 on:** February 22, 2014, 03:19:30 PM »

Thanks OZ!

Hot air engines need that little bit of magic to be successful.

But, the correct design, in the planning process is a good help!

Two earlier adventures. Both with the same problem as this one....

http://madmodder.net/index.php?topic=7223.0

http://madmodder.net/index.php/topic,8821.0.html

David D

fcheslop · « **Reply #3 on:** February 23, 2014, 01:59:46 PM »

That will keep you busy. No magic needed just a big hammer
You only need one qualification to build hot air engines

Thanks for the cuppa

Stilldrillin · « **Reply #4 on:** February 23, 2014, 02:49:41 PM »

Quote from: fcheslop on February 23, 2014, 01:59:46 PM

That will keep you busy. No magic needed just a big hammer
You only need one qualification to build hot air engines
Thanks for the cuppa

Frazer.
If I could wield a "big hammer" the way you seem to do. I'd be a happy man!

That one qualification isn't lacking here. Or, is it just stubbornness?

Cuppa? Any time Pal!

David D

krv3000 · « **Reply #5 on:** February 27, 2014, 04:22:29 PM »

well this will be brill once its all dun

Stilldrillin · « **Reply #6 on:** February 28, 2014, 02:51:55 PM »

Thanks for your confidence in me, Bob!

I had a good think, about making a new hot cap/ displacer, with the largest possible diameter. The 24mm dia locating recess is the limiting factor.

Trepanned through the square flange.

Piece of 1" dia tube. It's bore cleaned up at 22.5mm.........

Set up central to the mounting holes pcd.......

And bored to 24mm, plus a bit........

Friction turned a 1.5mm thick, end plug.

The machining heat glued it to the delrin. Handy for deburring........

Flux and silver solder.......

Penetrated nicely........

Cleaned up nicely.........

T'other end. No small dia solder in stock.........

Nicely filled, and penetrated........

Cleaned up ok. Spigot to 24mm......

That should make an improvement.......

Steel displacer, next.

Thanks for looking in.....

David D

Stilldrillin · « **Reply #7 on:** March 09, 2014, 06:45:30 PM »

Next job. The displacer

I found a piece of thin wall steel tube. (Handle from a Vileda mop), 21.5mm o/d. Perfectly matching the hot cap bore of 22.5mm.

Silver soldered the hot end. Same as hot cap, previously.

Turned a top hat bush, with 6mm spigot, for M3 thread. Also, a groove, for solder......

Formed solder ring. Fluxed. Then closed together........

With no vent hole, the solder burped a couple of times as it melted. Worked ok though.......

Cleaned up. Drilled/ tapped, then fitted the displacer shaft.

Comparison to original components.......

I adjusted the displacer to give 1mm clearance, at either end of stroke.

Then literally, just screwed the parts together. For test purposes.

And, tested..........

It's a (noisy) runner! Oh HAPPY DAY!!!

Several of the sloppy linkages need bushing/ shimming. A couple of shafts need replacing, and a new wooden base. But, overall I'm pleased with progress.

Thanks for looking in!

David D

krv3000 · « **Reply #8 on:** March 09, 2014, 06:57:06 PM »

see i sed it wood turn out ok well dun you

Stilldrillin · « **Reply #9 on:** March 10, 2014, 05:56:39 AM »

Quote from: krv3000 on March 09, 2014, 06:57:06 PM

see i sed it wood turn out ok well dun you

Thanks for your confidence in me, Bob!

Now, we've got a runner. Just need to make it into a tidy, quiet runner.

One that is appealing to steamtoy enthusiasts........

David D

tom osselton · « **Reply #10 on:** March 10, 2014, 05:23:41 PM »

looks and runs good, I haven't looked into these type of engine yet but it is on the list.

Stilldrillin · « **Reply #11 on:** March 10, 2014, 06:24:16 PM »

Thanks Tom!

When you get to the appropriate part of the list, be careful. These things can drive you to distraction.........

David D

Brass_Machine · « **Reply #12 on:** March 10, 2014, 11:32:51 PM »

Ya know David, I like the noisy part of that engine. Gives it some character (well, more character).

Nice job, it looks factory!

Eric

Stilldrillin · « **Reply #13 on:** March 16, 2014, 06:51:47 PM »

Thanks Eric.
I've left a couple of borderline loose pivots. Just to add character.......

Made some more progress.

A new left hand, half shaft. The original had been filed, enthusiastically.
Brass spacers, to position the crank throws.
Washers between moving parts.
And four, healthier looking nuts & washers, to hold the assembly together........

A new, better fitting replacement piston. To replace the undersize replacement(?) piston......

Opening out the cooling fins, for the larger o/d hot cap.
Hoping I don't finish up with a set of washers........

That fits, nicely.........

The engine is now finished. Just needing a new base board.

I found this redundant Maiwald base. Should be able to plug the holes, and tidy it.......

Not too long, now......

Thanks for looking in!

David D

AussieJimG · « **Reply #14 on:** March 17, 2014, 04:46:58 AM »

Always worth watching David.

Jim

Manxmodder · « **Reply #15 on:** March 17, 2014, 08:00:57 AM »

Looking really good David, look forward to seeing it when it's all finished....OZ.

Stilldrillin · « **Reply #16 on:** March 19, 2014, 07:04:21 AM »

Jim, OZ.
Thanks Chaps!

Not long now.

Thought I'd show the finished base, before it has an engine fixed to it.......

Turned some 3.5mm wooden plugs from dowel, and the smaller 2mm ones, from barbeque skewers.

The faced off end of the dowel, is flush with the face of the base. Tidying the surface, but not disguising it's previous life.

When the paint's fully cured, I'll assemble the engine to it.

David D

Stilldrillin · « **Reply #17 on:** March 19, 2014, 01:44:24 PM »

All done! Here we go.......

I don't do polished n shiny. So, I've left the original parts as is, to show their history.

Final video. Sometime soon........

David D

tom osselton · « **Reply #18 on:** March 19, 2014, 04:25:35 PM »

Well done!

SwarfnStuff · « **Reply #19 on:** March 20, 2014, 02:52:03 AM »

Beauiful job well done. Looking forward to see it running.
Congrats,
John B

Stilldrillin · « **Reply #20 on:** March 21, 2014, 03:21:56 PM »

Tom, John.

Thank you!

It's spent some previous time in a rather damp environment.

But, I always try to preserve previous patina........

Time for the final video.

Still a bit tight. But happy.......

Thanks all. For following along.

David D

philf · « **Reply #21 on:** March 21, 2014, 04:42:53 PM »

That's super David.

Maybe when I've finished my loco (and my clock and my CNC lathe) I'll have a go at one.

Is there a book on hot air engines you can recommend?

Phil.

Stilldrillin · « **Reply #22 on:** March 21, 2014, 06:44:13 PM »

Thanks Phil!

You be careful what you get into.

These things can drive you to distraction. But, I love 'em! Dunno why.....

I've tried to read several books on the subject. Found them very boring. Don't think I own one now.

I sort of learned about what was needed, over the past 4 years on here.
Hot end. Cool end. Decent ratio between swept volumes. As little friction as possible.
Above all, don't throw it at the wall in frustration. It will run, in the end. Possibly......

David D

krv3000 · « **Reply #23 on:** March 21, 2014, 07:27:51 PM »

well dun

fcheslop · « **Reply #24 on:** May 16, 2014, 12:19:45 PM »

Nice one David . sorry missed it.
Some good info on Jan Ridders site
http://www.ridders.nu/Webpaginas/pagina_overzicht_happermodellen/happeroverzicht_frameset.htm
Be very careful one burn and you become an addict and will sit there for hours twiddling flywheels round n round to find elusive tight spots and mysterious air leaks and once you got it running the beggar stops and the whole procedure is repeated but they rock.

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Author Topic: The Rainbows Engine....... (Read 17277 times)