Search found 12 matches

by hayman
Wed Aug 17, 2011 11:16 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Need help with our gamma school project engine
Replies: 31
Views: 22344

Re: Need help with our gamma school project engine

We just have one of those laser point temp guns at work. We are having off and on success with a alcohol flame. We can get it to run everytime with a mapp gas torch... Do you thing the heating section on our displacer is too short. As in the cooling fins are 2" long and the heating is only 1&qu...
by hayman
Tue Aug 09, 2011 10:39 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Need help with our gamma school project engine
Replies: 31
Views: 22344

Re: Need help with our gamma school project engine

here's something interesting. the engine runs better in a vertical position with the hot side of the displacer facing down. We are now getting it to run on a small alcohol flame.
by hayman
Mon Aug 08, 2011 2:45 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Need help with our gamma school project engine
Replies: 31
Views: 22344

Re: Need help with our gamma school project engine

Also on the clearance between the displacer piston and sleeve we seem to get two inputs. Some people say 1 mm (.040") and others are saying you want it as tight as .015". We made ours to be a .040" all around, do you think we would notice a increase with a larger diameter displacer pi...
by hayman
Mon Aug 08, 2011 2:39 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Need help with our gamma school project engine
Replies: 31
Views: 22344

Re: Need help with our gamma school project engine

Right now we have the stainless cap right on the alum fin radiator. We made a alcohol burner that gets the tip up to 580 degrees F but drops down to about 380-400 when the engine is cycling. With the alcohol it does not keep it running and the only success we have had was with the tip burning red un...
by hayman
Wed Aug 03, 2011 1:16 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Need help with our gamma school project engine
Replies: 31
Views: 22344

Re: Need help with our gamma school project engine

UPDATE!

We removed the bearing, took the plastic dust caps off and cleaned out the thick grease. We then applied a light oil... it runs. It is not fast however... We have to hit it with a lot of heat due to the paper gasket burning away and creating a leak.

http://youtu.be/qoNU2bDiOoc
by hayman
Wed Aug 03, 2011 10:18 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Need help with our gamma school project engine
Replies: 31
Views: 22344

Re: Need help with our gamma school project engine

Well just finished machining a stainless cap with a .015" wall thickness. The engine still does not run.... Also I cut the weight of my 3" flywheel from 500grams to 285grams by removing some of the thickness in the center. It may be in the bearing that is on the crankshaft/flywheel. Free s...
by hayman
Tue Aug 02, 2011 2:08 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Need help with our gamma school project engine
Replies: 31
Views: 22344

Re: Need help with our gamma school project engine

longboy I think you misunderstood me. I want to isolate the stainless heating tip from transferring heat to our aluminum sleeve with the cooling fins. We have some paper gasket material you can make engine gaskets with, that should help prevent heat transfer. We have some stainless in the shop so we...
by hayman
Mon Aug 01, 2011 4:32 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Need help with our gamma school project engine
Replies: 31
Views: 22344

Re: Need help with our gamma school project engine

If we made the hot side of the displacer sleeve out of stainless would we need to isolate the heat from traveling to the cooling fin alum side of the displacer sleeve?
by hayman
Mon Aug 01, 2011 2:58 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Need help with our gamma school project engine
Replies: 31
Views: 22344

Re: Need help with our gamma school project engine

We have a ball bearing on the crankshaft and all the connecting rods are just dowels.
by hayman
Mon Aug 01, 2011 2:57 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Need help with our gamma school project engine
Replies: 31
Views: 22344

Re: Need help with our gamma school project engine

Both the displacer piston and sleeve are made from aluminum. We do have a piston machined from delrin that we was going to try to prevent thermal shorts but we thought that maybe the engine would get too hot. So it looks like the hot tip on the sleeve we need to machine out of steel...
by hayman
Fri Jul 29, 2011 8:35 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Need help with our gamma school project engine
Replies: 31
Views: 22344

Re: Need help with our gamma school project engine

oh and i forgot the shaft on the displacer has a oil lite bronze bushing and the power piston is also in a oil lite bronze bushing. This creates a good seal with little friction
by hayman
Fri Jul 29, 2011 8:33 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Need help with our gamma school project engine
Replies: 31
Views: 22344

Need help with our gamma school project engine

Me and my partner are building a gamma type engine for a school project. The size of the engine is .500" dia power piston, .750" dia displacer with 2.25" length. The flywheel is made of bronze in 3" diameter. The inside of the displacer sleeve is .830" leaving approximately ...