Stirlingengineforum.com

I don't think your engine is going to work, because it doesn't have anything to store momentum (the job done by a flywheel in a mechanical rotary engine). The running engine contains two elements absent from yours- the first is simply a large volume of water. The water will act as an inertial mass w...

nobody puts the power cylinder midway between the hot and cold cylinders in Stirling. Erm... I did, and my engine runs fine. The venerable walking beam engine has the power cylinder mid-way between the hot and cold ends. I can also confirm that the power piston does exert a force on the outwards st...

Your diagram illustrates horizontal pistons moving in tandem and in derwoods diagram vertical cylinders with pistons move 180 degrees. I agree they will shuttle air but with no volume change then where is the pressure change? At the power cylinder, which can move in and out just like a conventional...

Drat, forgot my own diagram. Imagine the double-piston-dumbbell-thing and the power piston moving in 90 degree phase and I think you'll get it.

I think I'm possibly the only person who gets the idea here... as far as I can tell, what derwood is talking about is not really an alpha or gamma type engine... the closest thing I can think of would be the "moving cylinder" types, as in this design "displacer" doesn't make sens...

You've probably seen it before, but this flexible PV sheet sounds like an intermediate step in the right direction. I think it's about the 6% efficiency mark, but costs 2-4 US dollars per watt of capacity and weighs perhaps 100 lbs/kW capacity, so could probably go on your roof without serious reinf...

Wanting a nice smooth cylinder and piston for low friction isn't OCD, it's attention to detail :) When you are machining parts to half a thou' and making your own crankshaft balancers we can talk about OCD. Remember to post pictures of that mirror-finish cylinder!

Hi Zeph, I think the answers to your questions boil down to yes, no, probably not much. A stirling engine runs on a temperature difference- the bigger that difference, the more power the engine can get. Simple tin-can engines are inefficient and need a high temperature difference, and it's a lot eas...

Hi Phillip, I like your plan, and it's definitely a laudable aim, this is just a "back of the envelope" calculation to work out if your plan is feasible. An engine can lift water as far as you want (in theory) but lifting large volumes is a different matter. ------------ If we assume a usa...

I have had this problem as well, though I thought it might be due to some residue left inside the displacer cylinder. I just leave the engine with the piston taken out if it's standing for long periods, because the condensation wasn't doing wonders for the brass piston :shock: though I haven't seen ...

Bigsteve, Of the factors you mentioned in your original post all but one of them seem to be design factors, not properties suitable for tweaking and iterative improvement. Reducing friction (obviously) Displacer volume (increase vs. decrease) displacer bore displacer stroke The optimal displacer vol...

Dave, I believe that engine is a fairly well-known design by Andy Ross. The design was written up in an article which you can read online here (also thanks to greenpowerscience) and he produced kits at one point. The body of the engine is a moulding- the part of the crankcase you don't see behind th...

If you can get a 7H (or other high number- more than a 2H at any rate) pencil, that will contain much more graphite and less clay then an ordinary HB pencil. I don't think even 7H is pure graphite but it's probably much better than a regular pencil.

I'm not an engineer, but the few things about regens I do know are: - Packing should have a high surface area (packed metal discs with holes or steel wool/coarse swarf are common choices). Metal is the most common choice as it's easy to shape and conducts heat well, though in theory something non-co...

I've made a displacer out of a roughly 70mmx70mm section cut from an aluminium drink can with flat steel sheet glued over either end. I made the cuts neat and flat, and used plenty of JB Weld to make the join, so I suspect the displacer is now pretty much completely airtight. I know the displacer is...