Search found 2219 matches

by Ian S C
Sat Aug 06, 2011 4:16 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Heliostat Solutions for aiming parabolic reflector?
Replies: 8
Views: 7075

Re: Heliostat Solutions for aiming parabolic reflector?

Hi pj, I was just thinking of this problem today (for a solar water heater. Here just north of the 45 parallel, there is quite a difference in sunshine hours winter to summer, so I was thinking about the different tracking speeds that would be required. I was wondering whether I should have continuo...
by Ian S C
Sat Aug 06, 2011 3:57 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Need help with our gamma school project engine
Replies: 31
Views: 17840

Re: Need help with our gamma school project engine

hayman, one unfortunate thing about this particular design is that there is no provision with this type of crankshaft to drive anything, if it had an extension, a little fan would make quite a difference. What are you using for a power piston? If its still aluminium, now is the time to change to cas...
by Ian S C
Thu Aug 04, 2011 5:28 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Need help with our gamma school project engine
Replies: 31
Views: 17840

Re: Need help with our gamma school project engine

hayman, congrats, you need a high temp jointing compound in there, but you found that. On your new hot cap I would thin the flangeto about 1/8" if you can, that will be less metal to retain heat. As I build my motors, I have a small set of scales (for weighing food for some diet system), they g...
by Ian S C
Wed Aug 03, 2011 2:25 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Need help with our gamma school project engine
Replies: 31
Views: 17840

Re: Need help with our gamma school project engine

hayman, I don't think you have too much to worry about with heat conduction,hot to cold, keep the stainles cap as thin as possable, this with restrick heat flow along the cylinder, the joint it's self is a heat barrier, more so if there is some sort of gasket. None of my motors have any heat insulat...
by Ian S C
Mon Aug 01, 2011 6:00 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Gamma-Type Wood-Stove Striling Design & Construct
Replies: 4
Views: 5548

Re: Gamma-Type Wood-Stove Striling Design & Construct

John Pain, I,v built two of these, the first a Ringbom type (the displacer is free, ie., not connected to the crankshaft)this one is a bit too noisy. The second one is a Gamma type. The displacer cylinder is made from a Chrome plated mild steel tube from a vacuum cleaner extension, I welded a bit of...
by Ian S C
Mon Aug 01, 2011 5:16 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Need help with our gamma school project engine
Replies: 31
Views: 17840

Re: Need help with our gamma school project engine

hayman, you have a nice looking little motor there. A steel, or preferably cast iron cylinder, with a cast iron piston is about the best all metal solution, ie low coefficent of friction, Aluminium is about as bad as it gets unless it is hard anodised, there is also a teflon coating (just a few micr...
by Ian S C
Sat Jul 30, 2011 3:32 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Displacer/chamber diameter ratio
Replies: 13
Views: 12216

Re: Displacer/chamber diameter ratio

With a small high temperature motor, with a long, narrow displacer (L=3x the dia), a certain amount of regeneration occurs along the length of the displacer. On LTD motors i'm not sure if any measurable effect can be gained with regeneration, but I did see plans for one motor using a thin disc of fo...
by Ian S C
Sat Jul 30, 2011 3:22 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Need help with our gamma school project engine
Replies: 31
Views: 17840

Re: Need help with our gamma school project engine

hayman, If you can, make the displacer cylinder from stainless steel, .5 mm thick at the hot end is a good thickness, apart from alowing the heat to pass through easily, it restricts the flow of heat along its length. You did'nt say what you made the displacer from, it to should be stainless, and I'...
by Ian S C
Thu Jul 28, 2011 5:38 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Displacer/chamber diameter ratio
Replies: 13
Views: 12216

Re: Displacer/chamber diameter ratio

Ivspiano, I'm not much into LTD motors, but I'v built one, it's 6" in dia, with a 1" dia power piston, it runs on a bowl of hot water, or ice packs. The aluminium for the top and bottom plates were frying pans, and the displacer cylinder is a 1 1/4" length of 6" plastic water pip...
by Ian S C
Wed Jul 27, 2011 5:08 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Displacer/chamber diameter ratio
Replies: 13
Views: 12216

Re: Displacer/chamber diameter ratio

Ivspiano,A gap of 1 mm to 1.5 mm is a good starting place, 2 mm will work. With a displacer of 1.25" the displacer should be about 3.75" long,make the cylinder 3 or 4 mm longer than the displacer plus the stroke. If you can make both parts out of stainless steel, the hot end of the cylinde...
by Ian S C
Wed Jul 27, 2011 4:37 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: glass piston and cylinder
Replies: 5
Views: 6070

Re: glass piston and cylinder

Don't worry Shanex, I locate most of my materials as freebies, although sometimes I do give in and buy some bits, like pieces of aluminium tooling plate that I can get from a local companies scrap bin. Or I sometimes buy replacement skateboard wheel bearings, 8 mm bore, and about a $ each. Ian S C
by Ian S C
Tue Jul 26, 2011 5:11 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: glass piston and cylinder
Replies: 5
Views: 6070

Re: glass piston and cylinder

Shanex, the last motor I built is a GAMA, based on the ALPHA design from Koichi Hirata's boat engine, my motor has a stainles hot end, and a mild steel displacer. I intend to build an ALPHA vertion when all the bits come together. Glass syringes would be handy, but I don't know where I would get one...
by Ian S C
Mon Jul 25, 2011 4:08 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: pot pot boat
Replies: 14
Views: 12749

Re: pot pot boat

Carnot, you could(stretch a point) say that the water at the end of the tubes closes the tubes, and the steam from the boiler(now condensed) is the piston, the slug of water oscillates ack and forth in the tubes, flashing to steam , then condensing. Ian S C
by Ian S C
Thu Jul 21, 2011 6:25 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: glass piston and cylinder
Replies: 5
Views: 6070

Re: glass piston and cylinder

Shanex, If you look on google, you'll find Koichi Hirata in Japan http://www.khirata@gem.bekkoame.ne.jp this chap uses glass syringes for pistons and cylinders, and his motors are well worth looking at. there is a thread someware (I can't find it just now) about using comercial glass cylinders with ...
by Ian S C
Thu Jul 14, 2011 6:31 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: pot pot boat
Replies: 14
Views: 12749

Re: pot pot boat

Jim, I think it could possibly be called a thermo acoustic motor, with a hydraulic piston. actually its a flash steam boiler, the small amount of water in the boiler almost instantly turns to steam, that expands (1200 times in volume I think), it pushes out the tail pipe, and a partial vacuum is for...