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Re: TWIN 32 x 38 mm - steam engine for small boats or canoes

Posted: Sat Jan 22, 2022 8:44 pm
by dampfspieler
Hi,

a picture of the cylinder covers. They have the shown recess. With the shape shown, i hope to keep the flow losses of the vapor low.

Twin3238_231kl.jpg
The cylinder covers.
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The valve chest cover has been given a threaded hole in order to be able to drain the valve chest.

Twin3238_239kl.jpg
The finished valve chest cover.
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The valve chests have two threaded holes at the upside for connecting a valve chest pressure gauge and lubricating the slide valve after the end of operation.

Twin3238_245kl.jpg
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--
Dietrich

Re: TWIN 32 x 38 mm - steam engine for small boats or canoes

Posted: Sun Jan 23, 2022 2:20 am
by barts
dampfspieler wrote:
Sat Jan 22, 2022 7:57 pm
was your bearing an open or an closed type?
I will use closed ball bearings on all eccentrics of my engine. They have a life time lubrication.
I had a slight bit of side motion (.030) or so on the end of the eccentric arm as I used a rocker arm to drive the horizontal slide valve. Thus I used two bearings side by side and a flexible arm. The bearings were open, but never gave me any trouble. They were well-oiled. This was a 2" x 2" 2 cylinder single acting engine that I made from from an old refrigeration compressor.

- Bart

Re: TWIN 32 x 38 mm - steam engine for small boats or canoes

Posted: Sun Jan 30, 2022 9:25 pm
by dampfspieler
Hi,

there was some progress over the weekend. The base plate was milled, the holes and the threads were made.

The cylinder cover gaskets were cut and put on for testing. The steam channels were milled to the finished size. They are dimensioned so large that the steam speed remains below 20 m/s at a speed of 1,000 rpm and maximum filling.
Twin3238_252kl.jpg
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Twin3238_253kl.jpg
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The pistons were fastened to the piston rod, then placed in the collet and turned to the final size so that, when oiled, they slowly sink through the cylinder under their own weight.

Twin3238_254kl.jpg
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Dietrich

Re: TWIN 32 x 38 mm - steam engine for small boats or canoes

Posted: Sun Jan 30, 2022 9:36 pm
by dampfspieler
Hi,

the mounting holes for the crankshaft bearing blocks have a diameter of 9 mm, but the mounting bolts are only 8 mm thick. That's why I turned appropriate centering sleeves out of brass.

Twin3238_262kl.jpg
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Twin3238_263kl.jpg
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The mounted centering sleeves, they are functional and an eye candy.

Twin3238_267kl.jpg
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--
Dietrich

Re: TWIN 32 x 38 mm - steam engine for small boats or canoes

Posted: Sun Jan 30, 2022 9:48 pm
by dampfspieler
Hi,

at the end of the day, I assembled all the currently finished parts and weighed them, currently 12 kg of metal. I also adjusted the center distance of the bevel gears so they run smooth and quietly.

Twin3238_279kl.jpg
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The gears set to the right distance.

Twin3238_286kl.jpg
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I am a bit happy
Dietrich

Re: TWIN 32 x 38 mm - steam engine for small boats or canoes

Posted: Mon Jan 31, 2022 4:10 pm
by PeteThePen1
Well done Dietrich that looks really magnificent. By the way, I do like the collar for the bolt. A nice simple but very effective idea. So if that was all my own output, I would be feeling more than happy. How about ecstatic?

An idle thought to share with our expert friends is to think about how one might reduce the weight if the engine was destined for a canoe. The thing I would suggest would be to use alloy wherever possible. The bearing housings do not need to be steel, nor probably the engine bed. Could one use hollow tube for the pillars? Then I suppose one could possibly copy automotive practice and have an aluminium block with steel/cast iron liners. Aluminium pistons? What would our experts advise?

Regards

Pete

Re: TWIN 32 x 38 mm - steam engine for small boats or canoes

Posted: Mon Jan 31, 2022 5:30 pm
by DetroiTug
''The bearing housings do not need to be steel, nor probably the engine bed. Could one use hollow tube for the pillars? Then I suppose one could possibly copy automotive practice and have an aluminium block with steel/cast iron liners. Aluminium pistons? What would our experts advise?''

Expert in training reply: Yes yes yes, aluminum cylinder with a sleeve? Probably not, Alumin(i)um has a very high expansion rate with temperature and the likelihood of losing the fit of a cast iron sleeve at steam temp is very high. In my line of work we install and need to remove aluminum pulleys from steel shafts occasionally, if stuck, heating the pulley slightly will enable it to fall away. Aluminum pistons, yes, with cast iron rings.

Ron

Re: TWIN 32 x 38 mm - steam engine for small boats or canoes

Posted: Tue Feb 01, 2022 10:22 am
by Mike Rometer
From my automotive stand point an Ali block with liner should prove no problem. The fit is usually extra secured by the cylinder head (and we have one both ends). It works with I.C. temps which are far higher than steam, so forget that worry. The liner could also be heat shrunk in.

My twin, although as yet unfinished or proven, has Ali pistons.

Re: TWIN 32 x 38 mm - steam engine for small boats or canoes

Posted: Tue Feb 01, 2022 2:08 pm
by DetroiTug
"an Ali block with liner should prove no problem''

With superheating?

Re: TWIN 32 x 38 mm - steam engine for small boats or canoes

Posted: Tue Feb 01, 2022 2:21 pm
by dampfspieler
Hi,

in view of the questions and comments, I would like to recall the first few sentences.

-------------
There was a second cylinder block when i got my steam lorry MARTIN because there was a water hammer on the steam engine so that the cross head guide and the piston rod were destroyed. I repaired them and the lorry runs well but the cylinder block was now left.

This cylinder block with the given external dimensions forms the basis for a small steam engine comparable to that of my steam lorry. I checked the steam channels and found them to be too small and expanded them in the first step.
-------------

Using existing parts, commercially available components and the facilities I have in my workshop, I would like to build a small steam engine of about 1 kW that is reliable and easy to operate, which Peter encouraged me to do. I find this to be a sufficiently large challenge in the first step. When that's done, it's a matter of finding a suitable hull and launching a functioning small steamboat that you can hang under the ceiling in the carport if you want.
When that is done, the unit of engine, boiler and boat can be revised and optimized.
Given the fact that the community of vape enthusiasts around the world is getting smaller, I think this is a promising way to broaden the base.
And a very important point is that like many others here I am also a grandfather and therefore I put some priorities on obvious successes.

As things currently stand, I'll leave it to other enthusiasts to implement the above ideas

Best
Dietrich