Search found 66 matches

by SScandizzo
Mon Aug 21, 2006 12:00 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: cylinder ratios
Replies: 14
Views: 33868

Hi Wayne, Welcome to the forum! A couple of simple formulae to keep in mind. 1) The displacer cylinder is ideally divided into 1/3 cool and 2/3 hot. The displacer itself should be about 2/3 the total length of this cylinder. Also the ratio between the displacement volumes of the two cylinders is 33%...
by SScandizzo
Mon Jul 24, 2006 6:17 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Dual Acting Cylinders
Replies: 27
Views: 22021

Stan, I started thinking about your notes and I admit that I will have to chew on that design a bit more before I try to build it. I agree that it seems straight forward at first glance, but think you may be right that since pressure changes on both sides may not always be reciprocal there could be ...
by SScandizzo
Mon Jul 24, 2006 6:09 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: First Test Successful
Replies: 2
Views: 4081

Way to go, Jumpers. I think the first successful engine is the toughest. On a few of my posts I have referred to my "test bed" engine but I hadn't given a description of it, so here it is. http://www.stirlingengine.com/file-storage/download/beam_stirling.jpg?version_id=254 It is a gamma beam engine ...
by SScandizzo
Fri Jul 14, 2006 12:57 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: mounting distances for heat/cooling tanks?
Replies: 4
Views: 5543

I think its safe to say that increased heat and cold will generate more power per stroke. HOWEVER, there is a practical limit. Take a LTD (low temperature differential) engine as an example: I wouldn't recommend putting a propane torch on the hot side of one of those as the tolerances and materials ...
by SScandizzo
Fri Jul 14, 2006 12:47 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Displacer motion
Replies: 9
Views: 8822

Point made, Jumpers. Let's call it a "modified Stirling cycle" then? There are a number of designs (such as Ringborn engines) that don't follow the strict specifications either but are commonly labeled as Stirling engines.

-Stefan
by SScandizzo
Thu Jul 13, 2006 5:16 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: mounting distances for heat/cooling tanks?
Replies: 4
Views: 5543

Jumpers, While I haven't built this particular engine, I can confidently make some suggestions. The purpose of the fire box and the water tank is to provide a temperature gradient across the displacer cylinder. The greater the differential, the more efficient the engine will be. As a general rule, I...
by SScandizzo
Wed Jul 12, 2006 11:11 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Flywheel sources are abundant
Replies: 1
Views: 3956

Hard drive platters make great heat sinks, too!
by SScandizzo
Wed Jul 12, 2006 11:08 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Displacer motion
Replies: 9
Views: 8822

I'm in the process of building a second engine with the same specifications as my test bed engine. When completed, I plan to modify the original to use an intermittent movement displacer. I also just got done building an electronic counter that allows me to measure the RPM of my engines without inte...
by SScandizzo
Sun Jun 25, 2006 2:40 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Commercial uses for Stirling Engines(?)
Replies: 10
Views: 8790

Much of the material you read about Stirling engines describes them as "low power" machines. Unfortunately, this depiction is often taken out of context. Keep in mind that the variety of heat sources is very broad; from petrolium products, to natural gas, to biomatter (wood, ethenol, etc.) to direct...
by SScandizzo
Thu Jun 22, 2006 10:20 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Displacer type stirling engine
Replies: 3
Views: 6735

Dave - What you are describing is a low temperature difference (LTD) Stirling engine. There are a few designs out on the internet, but few are free. Here's one that I've found (but haven't tried personally) http://www.pureenergysystems.com/os/StirlingEngine/photologie/index.html Another more convent...
by SScandizzo
Thu Jun 22, 2006 10:07 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Displacer motion
Replies: 9
Views: 8822

A rotary displacer doesn't provide an intermittent heating and cooling cycle: it remains sinusoidal, which is my original concern. Keep in mind that there is a good reason that the Wenkel (rotary IC engine) hasn't supplanted the standard piston models: they are more expensive to manufacture and much...
by SScandizzo
Thu Jun 22, 2006 10:00 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: New design
Replies: 1
Views: 3689

It's tough to build a better mouse trap...

http://www.rotarystirlingengines.com/birotor.htm

-Stefan
by SScandizzo
Wed Jun 21, 2006 1:10 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Displacer type stirling engine
Replies: 3
Views: 6735

Hi Dave, Welcome to the forum and the Stirling engine building hobby! First off, glass syringes and test tubes are an excellent material for power cylinders not made on a lathe. Be sure your piston is air tight and that you do not use any form of lubricant in the cylinder. To answer your question, I...
by SScandizzo
Sun Jun 11, 2006 9:44 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Dual Acting Cylinders
Replies: 27
Views: 22021

My thought was that this configuration could develop power similar to a normal paired two cylinder configuration with the advantages of having only one output crank and less friction from having only one power cylinder/piston. I've seen a double hot capped alpha using only one power piston but that ...
by SScandizzo
Thu Jun 08, 2006 9:22 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Dual Acting Cylinders
Replies: 27
Views: 22021

You got me there, Stan. The correct term is "double acting cylinder". After looking at the bi-rotor engine, I still believe a conventional layout is more practical in terms of serviceability and experimentation. Granted there would be at least 3 seals (one on each displacer cylinder and one on the p...