Author Topic: Strictly.... “ Hot Air “  (Read 21715 times)

Offline Alyn Foundry

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Strictly.... “ Hot Air “
« on: October 26, 2017, 06:21:49 PM »
Hello All.

I thought a dedicated thread for all engines that use expanded air might be a useful addition to the forum.

Some will remember that I used to sell a half scale replica of the Robinson number 4 hot air engine, production stopped when Rhuddlan foundry closed. The main reason was that nobody could make the highly complicated mould that used 3 different cores just to make the platform. The other problem arose when the price of Aluminium scrap topped the £1000.00 per Ton mark and four of my Aluminium master plates were stolen from Buckley who produced the cylinder castings.

Thanks to Andy ( Chipmaster ) we have had some new cylinders cast and I have just finished or should I say refinished my old Robinson Hot Air Engine that became a cylinder donor to an old customer several years ago.

Some pictures and a video to come later....

As this is an open thread please post any “ Hot Air Engine “ related builds or pictures of your engines here.

Cheers Graham.

Offline Jo

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Re: Strictly.... “ Hot Air “
« Reply #1 on: October 26, 2017, 06:30:33 PM »
Some pictures and a video to come later....

 :pics:

Jo
Usus est optimum magister

Offline Alyn Foundry

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Re: Strictly.... “ Hot Air “
« Reply #2 on: October 26, 2017, 06:32:56 PM »
Indeed Jo.   ;)

Offline Alyn Foundry

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Re: Strictly.... “ Hot Air “
« Reply #3 on: October 26, 2017, 06:36:54 PM »
Top picture is the first half scale engine to be built by the Alyn foundry.

The lower picture is perhaps the earliest surviving Robinson patent engine built in the 1880's before Robinson's themselves. It's air cooled !!

Offline b.lindsey

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Re: Strictly.... “ Hot Air “
« Reply #4 on: October 26, 2017, 06:51:41 PM »
Nice pictures. Are both of them cast iron? They sure look to be. Very nice!!! As for the thread, are you looking for both stirling as well as atmospheric engines Flame Lickers)?

Bill

Offline Alyn Foundry

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Re: Strictly.... “ Hot Air “
« Reply #5 on: October 26, 2017, 06:52:05 PM »
A kit....

Offline Alyn Foundry

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Re: Strictly.... “ Hot Air “
« Reply #6 on: October 26, 2017, 07:06:15 PM »
Nice pictures. Are both of them cast iron? They sure look to be. Very nice!!! As for the thread, are you looking for both stirling as well as atmospheric engines Flame Lickers)?

Bill

Hi Bill.

I think my last post showing the ru... em patina tells you they're Iron.  :)

The lower picture is an original 130 year old engine at full scale.

Cheers Graham.

Offline Jasonb

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Re: Strictly.... “ Hot Air “
« Reply #7 on: October 26, 2017, 07:11:55 PM »
Graham, looking at the first two photos you posted the only major difference that I can see if teh valve on the end of the model cylinder, linkages look very similar. Are there any other variations that I can't see?

Must admit I like the look of the original engine, not sure if it is the shape or the bare iron that tickles my fancy :thinking:

I would think supporting the core(s) for the water space was quite difficult, the air passage not so bad as it can be supported at either end
« Last Edit: October 26, 2017, 07:17:24 PM by Jasonb »

Offline Alyn Foundry

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Re: Strictly.... “ Hot Air “
« Reply #8 on: October 26, 2017, 08:00:02 PM »
Graham, looking at the first two photos you posted the only major difference that I can see if teh valve on the end of the model cylinder, linkages look very similar. Are there any other variations that I can't see?

Must admit I like the look of the original engine, not sure if it is the shape or the bare iron that tickles my fancy :thinking:

I would think supporting the core(s) for the water space was quite difficult, the air passage not so bad as it can be supported at either end

Hi Jason.

Indeed, the simplicity of the air cooled engine is amazing.... I too like the unpainted theme.

The valve in the later design was a governor, a simple disc in the air tract that was held open by a light spring. As the air passed more rapidly the disc would be drawn forward against a step and close the power cylinder completely.... Not a good idea, so a couple of small holes were used in the disc to diminish the dead stop condition.

The water jacket core was a nightmare !!  Supported by " Chaplets " they used to " Blow " regularly to start with, but a newer resin bonded sand was used and we produced well over 200 kits.

Pictures are great, video even better !!   ;)


Cheers Graham.

Offline Ian S C

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Re: Strictly.... “ Hot Air “
« Reply #9 on: October 27, 2017, 11:39:04 AM »
one of our machinery club guys brought a Robinson over from Australia about three years ago, quite an impressive motor.
Ian S C
           

Offline b.lindsey

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Re: Strictly.... “ Hot Air “
« Reply #10 on: October 27, 2017, 01:16:49 PM »
That is quite a large engine and beautifully restored as well.

Bill

Offline Alyn Foundry

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Re: Strictly.... “ Hot Air “
« Reply #11 on: October 27, 2017, 01:31:40 PM »
Hi Ian.

Thanks for your input.

Do you know the bore and stroke dimensions? I believe the number 6 was 10” bore and the largest that Gardner’s of Patricroft built.

Note the extra cooling tank that doubles as the main bearing support.

Cheers Graham.

Offline scalemodel

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Re: Strictly.... “ Hot Air “
« Reply #12 on: October 27, 2017, 08:19:23 PM »
When I was 19 many years ago I brought a rider Ericsson from camdam minature steam services which I built, at the time they hadn't got any firebox castings in so they said they would send one I'm still waiting!! But that's another story

When the rider was done I brought a set of castings off the engineers emporium for their robinson engine which is quite a big model, not long after I brought these I got into model traction engines and the robinson never got started.
I may push the castings on or swop them for some other castings maybe steam related.

Just thought I would share my hot air experience

Jonathan

Offline Ian S C

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Re: Strictly.... “ Hot Air “
« Reply #13 on: October 28, 2017, 11:49:23 AM »
I have not measured the bore, but I would say it's near enough to ten inches,  It should be at a show near here in a few weeks, if I remember, I'll run a tape over it.
Ian S C

Offline Alyn Foundry

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Re: Strictly.... “ Hot Air “
« Reply #14 on: January 09, 2018, 03:25:24 PM »
Hello All.

Number 3 son Alan started on his Robinson hot air engine some nine years ago. School, college and an apprenticeship kinda got in the way....

However....


That’s a short run to test before painting, more to come.

Cheers Graham.