Stirling engines / easy energy

>>1064120
Steam would be much more efficient

>>1064129
>steam
Now there's a good idea, yeah. Hadn't really thought about it - a turbine might be out of my reach in terms of construction, a triple expansion piston generator would be a pretty cool project.

I'm facinated by Stirling engines but I've never seen one doing any real work ,i think it's an engine with a lot of potential but yeah steam would be better for your house or even just a diesel generator that would probably run the waste oil

>>1064142
It'd be easier to make a steam engine compared to a diesel, so I'll go with that to start with.

Any recommendations on what to use for current generation? I can get old car alternators pretty cheaply, I was thinking of connecting one or more of those up and using them to charge a battery bank, which in turn runs a 240V inverter that's plugged directly into the wall - would that work?

Op, here is the issue with a Stirling engine:

All engines base their output power on the temperature difference between the high and low temperate, how much volume is displace during the heat up, and how fast the heat up occurs

All Stirling engines tend to have a constant input temperature (candle flame etc) at a pretty low temperature gradient, and tend to have very tiny pistons so very little displacement

Unless you have an army of over 100,000 Stirling engines you won't be able to get a sizeable amount of power out

Not OP. But I tried twice to make sterling steam engines from scrap cans and such to no luck. I've read up on it, I looked at diagrams and followed them but none of my attempts worked.

Is there some kind of trick to this? I see them all the time on youtube and just wanted one for fun.

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>>1064142
There was a company that made generators out of them in the 60's for remote locations where efficiency was the major concern. Reducing fuel shipments and all that. They worked. The problem with them is they are complex to make and their power to weight ratio is poor. That said, there have been many used. Many types of modern solar concentrators use them. Pic related.

>>1064149
>All Stirling engines tend to have a constant input temperature (candle flame etc) at a pretty low temperature gradient, and tend to have very tiny pistons so very little displacement
Really? You make a tiny Stirling and it has tiny power output? Way to go Captain Obvious. Let's see if you connect the dots. What happens when you make a big one that isn't powered by a fucking candle?

>Is there some kind of trick to this?
Yes. Most of the people that make those scrap models have to make 3 or 4 before it works. So, practice is the key. This is one of the better ones I've seen that's made out of junk..

http://www.yaplakal.com/forum2/st/0/topic411405.html

>>1064214
Sterling engines can be made of any size. The small ones are popular demonstrations because they can run on body heat or tea candles.

There are a few types of sterling engines. The ones that heat an inert gas in the compression chamber are going to be pretty weak because you need to reheat the same air mass every cycle. Using a combustible gas in the chamber and you get a basic combustion sterling engine with a nearly instant release of energy.

>>1064149
Without seeing the engine I couldn't help. Try increasing the weight of the fly wheel and lowering the weight of the piston. Maybe you weren't replacing the expanded hot air with fresh cool air causing a vacuum in your expansion chamber?.

If I was making one, I'd make a steam engine. A boiler releasing into the compression chamber at least volume, closed by a light weight lag piston that get pulled up when the power piston nears max deflection. The power piston attached to a fly wheel and a valve open to the environment when the boiler valve closes.

>>1064218
The temperature gradient and the rate of temperature change are the key reasons why it doesn't scale well

>>1064120
>Would it be possible to make one that's powerful enough to take a sizable chunk out of my electricity bill, if I run it 24/7?

If you want to make a sterling engine then make a sterling engine.
But don't make one to use as a generator.

You can run gas engines off of wood gas, convert four and two stroke engines to compressed air/steam, and run diesels on waste oil.
And if you want to build your own engine, consider a steam turbine.
All of these are better ideas for a diy generator.

>>1064148
An alternator will work fine and won't need speed regulation. You'll need to provide excitation current, but that's not too hard and I trust you can search.

>>1064142
I may be mistaken but doesn't one of the mars rovers have a Stirling engine that uses some radioactive element as a heat source? Also I think I remember reading about some military submarine (some Scandinavian country I think) using one while submerged.

I'm a machinist and have wanted to build one but I haven't been able to find any good resources on designing one. I know I could buy plans but..... I really would like something that lays out some formulas and rules of thumb when designing one like volume ratios, strokes length, timing.... I know the end product would need tweaking but at least I would be starting off close.
Anyone know of anything?

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>>1064142
>>1064218
There are tons of them now.

>>1064230
Actually they scale very well, there's just no need to do so.

>>1064279
>I really would like something that lays out some formulas
Stirling Engines, by G. Walker. Or other relevant books by the same guy.
>and rules of thumb
Sorry, it's not really that kind of book.

>>1064294
>Sorry, it's not really that kind of book
Yeah. I have found plenty on "theory". Maybe I'll just jump into it and see how it goes. I'll try to document as much as my tinkering and experimentation and write the damn book I seek myself.

>>1064322
Well, I'd say it's still worth reading, even if it doesn't give you rules of thumb. If nothing else, it presents plenty of ways to implement things.

>>

https://en.m.wikipedia.org/wiki/Radioisotope_thermoelectric_generator

>>1064235
Agree. If beginner, Stirling engine will be stiff enough challenge. Don't add generator to it, especially for home