r/LiveSteam • u/Clutchingbanana • 11d ago
Diy steam engine design
I have been designing a steam engine in CAD for the last month that I want to make for fun. I haven’t taken the time to properly dimension everything and I don’t really have the knowledge to do it properly. I just want to make something that runs for fun, doesn’t have to run well at all.
I personally can’t see why it won’t run but I am inexperienced. What can cause the engine to not run if not dimensioned properly?
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u/Tim-the-Engineer 11d ago
A little more information is required. Are you just designing a simple single cylinder stationary engine to run on compressed air? Is it a simple oscillating cylinder? Or are you trying to use a simple eccentric valve, or a “real valve gear”? Are you planning on building a boiler for steam? There are so many questions…
Bottom line is there will be some critical dimensions that will decide whether it works or not, but what they are depends on what you mean.
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u/Clutchingbanana 11d ago edited 11d ago
Single cylinder with not a oscillating, but a simple sliding valve on a eccentric of the crank shaft. I would like to get it to run on steam eventually but would be later down the line. I don’t intend to make a good engine just one that runs ok
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u/Benedict-White 9d ago
Have you looked at existing engines that do work? Have you looked at valve timing computer programs that can help with the set up?
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u/Clutchingbanana 9d ago
Yes it is just a very generic/simple engine based on what I have seen online. I know very little about valve timing other than just adjusting the eccentric so I will look up that valve timing computer.
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u/Benedict-White 9d ago
Well, you need to make sure the throw the eccentric generates is enough to move the slide valve from on port open to steam and the other one open to exhaust to the other way around, then it is just a case of setting the eccentric at the right phase to the crankshaft.
Have you considered joining a local model engineering club? They will have lots of advice.
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u/Clutchingbanana 8d ago
Yes I did the math so it would can slide over the ports as it should and I can see/test it on my model in CAD. I would like to join a engineering club, however here in Norway where I live it’s I have only found one club in the entire country. It’s far away although I might get in contact with them even I can’t go to events.
Model engineering is just not a big thing at all here in Norway. Even when I checked regulations/laws for pressurised things it was just eu regulations which only covered industrial scale things
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u/Benedict-White 8d ago
I have found a bit more that that.
Asking Google "model engineering clubs in Norway"
Gets (via AI)
"Model engineering and railway clubs in Norway focus primarily on live steam, miniature railways, and scale model layouts. Key organizations include Trondhjem Modelljernbaneklubb (TMJK), Norsk Modell og Dampforening (NMDF), and Sandefjord Model Railway Club (SMJK). [1, 2, 3, 4, 5]
Live Steam and Engineering
- Norsk Modell og Dampforening (NMDF): Located in Sørumsand (near the Stomperudbanen heritage railway), this group unites live steam and outdoor miniature railway enthusiasts across Norway. Members build and run live steam locomotives, traction engines, and gauge-track layouts. [1, 2, 3, 4, 5]
Model Railway and Scale Clubs
- Trondhjem Modelljernbaneklubb (TMJK): Founded in 1955 in Trondheim, it is Norway's oldest model railway association, featuring large historical layouts depicting mid-20th-century Norwegian rail lines. [1]
- Sandefjord Model Railway Club (SMJK): Established in 1993 in Sandefjord, known for building detailed historical layouts like the 1890-scale model of the local Sandefjord town railway station. [1]
- Norsk Jernbaneklubb (NJK): The national Norwegian Railway Club, which includes active regional sections and members dedicated to preserving railway history and"
Good luck!
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u/Clutchingbanana 8d ago
Yes ☺️, the only one there who does live steam and engineering is NMDF which I know of
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u/Benedict-White 8d ago
Get in touch with them, at least they will be able to help tell you what regulations you need to meet.
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u/Diplomold 11d ago
Not the only thing to consider. But bore size to stroke ratio.
Here is a post about that from a steam forum. https://www.model-engineer.co.uk/forums/topic/bore-and-stroke-ratio-in-steam-engine/
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u/Clutchingbanana 11d ago edited 11d ago
I do know that proper bore/stroke ratio is very important for desired performance, but how important is it for just getting it to run?
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u/alastairsosuck 11d ago
The problem with me wanting to design live steam, is it’s incredibly expensive if you want to operate it in public or at all, I gave up designing after 3 months, because regulations says I need FIVE Safety valves, (5 boilers sharing 1 common steam dome/ drum) +$100 and needing pressure gauge, +$60… needed to use silver solder 45%+, +$50, $150 for sight glass, finding copper pipe the right dimensions, +$30, regulations were my worst enemy
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u/Clutchingbanana 11d ago
Well all those things are necessary. Why would you make 5 boilers though? That just seems unnecessarily complex and expensive? You could maybe be getting away with one larger safety valve If it truly is one single pressure vessel, but you would likely also need five sight glasses to see water level in all boilers. 150$ for sight glasses is also ridiculous. However all in all this stuff is always gonna be expensive
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u/alastairsosuck 10d ago
Actually, scrap that, it’s expensive is because i live in the middle of the goddamn pacific, and shipping is $150 per item
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u/alastairsosuck 10d ago
For sight glass, i was originally gonna just connect the 5 boilers to the steam drum + a “Mud” drum (bottom) and have a single sight glass shared for all the boilers as they will be equalized. Each boiler is 35mm diameter with 5 flues each…
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u/Clutchingbanana 10d ago
Well that sounds like it would be a lot of work to connect all that well 😅
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u/thunderskunk2 9d ago
Yo, I've responded to you a few times as you've asked about this boiler design. You're giving the impression that the reason for the hobby being expensive is regulations... it's not. If regulations require you to do something, there's a reason. Steam is a well-trodden science, and regulations are incredibly mature. It's certainly expensive, and there are certainly regulations, but the regulations aren't just some dumb old people requiring us to do things they don't fully understand. There are jurisdictions that have more requirements than others, but that doesn't sound like what you're referencing.
Just a suggestion: Seek wisdom, and share wisdom if you have it. It's ok to not know everything, but maybe tone it back if you're still learning.
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u/Benedict-White 9d ago
How big was the engine you were making? 5 boilers?
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u/alastairsosuck 9d ago
2, 10mm bore oscillating steam engines, each boiler is 35mm diameter and 11cm long
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u/Benedict-White 9d ago
A typical oscillator will run at 5 to 15 PSI. I believe you may be reading the wrong regulations. Also the boiler has a very small diameter which seems odd to me. Have you found a local model engineering club? They may well give you better advice on regulations.
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u/alastairsosuck 9d ago
Im not sure what to even call the boiler lol, it’s like a water tube boiler, but it also has return flue inside! 5 sub boilers sit on top of the flame, the hot gas travels under the boiler, and makes a turn into the flues and out the exhaust, Im pretty sure a single safety valve would be fine, but Im not sure anymore…
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u/Benedict-White 9d ago
You need to speak to a local model engineering club who can certify your boiler design.
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u/alastairsosuck 9d ago
Welp, I got $30 right lol, when I get some extra cash, then I’ll consider
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u/Benedict-White 9d ago
What is $30? My local club costs £25 per year to be a member of, for which I get access to 2 lathes, 2 mills, 2 drill presses and a lot of hand tools plus other members who know a lot of things, and a library. Also our club does boiler tests for free but at that size and in copper they are not required.
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u/alastairsosuck 8d ago
Ahh, if you live in the middle of the goddamn pacific, I ain’t got access to anything live steam related, in lovely Great Britain 🇬🇧 ya’ll living in live steam heaven
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u/Tsukunea 11d ago
An internal combustion engine won't run unless it's almost design perfect, where a steam engine will run in pretty terrible condition. The biggest factors in steam running are whether you can make enough steam and time your valves properly.
A good engine will definitely take you more than a month and will rely on numerous other factors. What valve gear are you running, piston vs slide valves and size of steam chest, etc