Search found 12 matches

by picnic
Sun Oct 02, 2011 9:25 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Smaller walking beam
Replies: 13
Views: 9602

Re: Smaller walking beam

Thanks Ian, as it stands it would have (75-55-10)/2 = 5mm clear at each end, isn't that enough? Yes, the displacer cylinder bush will be much longer!
by picnic
Sun Oct 02, 2011 4:08 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Smaller walking beam
Replies: 13
Views: 9602

Re: Smaller walking beam

Here's the first part of the drawings....comments welcome!
by picnic
Sun Oct 02, 2011 1:19 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: First run of beam engine
Replies: 8
Views: 7737

Re: First run of beam engine

Thanks Jim but it needs tweaking to run as smoothly as yours!
by picnic
Fri Sep 30, 2011 8:15 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Smaller walking beam
Replies: 13
Views: 9602

Re: Smaller walking beam

Am I right in thinking the displacer itself should be about 2/3 the volume of it's cylinder for this type of engine? I was thinking of a 20mm diameter displacer in a 25mm tube (air gap of 2.5mm) and making the displacer about 50mm in length.

TIA

picnic
by picnic
Thu Sep 29, 2011 12:33 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: First run of beam engine
Replies: 8
Views: 7737

Re: First run of beam engine

Cheers. I was contemplating replacing the disc with a much smaller (and true-running!) metal crank disc and adding a proper flywheel to the other side to smooth out the motion which as you noted is rather jerky!
by picnic
Thu Sep 29, 2011 11:26 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: First run of beam engine
Replies: 8
Views: 7737

Re: First run of beam engine

Thanks theropod2 - good tip. I replaced the displacer link and crank pin and fitted a water tank. I didn't have any soft solder to hand so I made the tank a good push fit on the top of the displacer cylinder and used some 'plumber's mait' quick setting epoxy (rated up to 160C) to seal the joint. Whe...
by picnic
Thu Sep 29, 2011 4:47 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Smaller walking beam
Replies: 13
Views: 9602

Re: Smaller walking beam

Oh, the 'full size' is just my take on the tin can beam engine - http://stirlingengineforum.com/viewtopic.php?f=1&t=880
by picnic
Wed Sep 28, 2011 1:03 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: First run of beam engine
Replies: 8
Views: 7737

First run of beam engine

Here's my almost complete variation of the tin-can beam engine - couldn't resist trying it out even though it still has some temporary/missing parts. Utterly surprised and delighted that it runs although it needs a fair bit of heat! http://www.youtube.com/watch?v=WHjKndxZtnI It's actually the second...
by picnic
Wed Sep 28, 2011 12:48 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Smaller walking beam
Replies: 13
Views: 9602

Re: Smaller walking beam

Thanks again. Just need to finish off my first "full size" engine and I'll get on to those drawings!
by picnic
Wed Sep 28, 2011 5:05 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Smaller walking beam
Replies: 13
Views: 9602

Re: Smaller walking beam

Thanks Ian... do you mean a ratio of 1.5:1 between the displacer cylinder and power cylinder or displacer itself? I'm going to make some drawings as I go and upload them, if you wouldn't mind looking them over that would be great :D EDIT: By my calculation the power cylinder would be around 9.5mm di...
by picnic
Tue Sep 27, 2011 1:14 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Smaller walking beam
Replies: 13
Views: 9602

Smaller walking beam

Is a smaller version of the tin can walking beam engine likely to work or is a minimum volume of air required? I was thinking of the displacer cylinder being perhaps 1 inch diameter and 2 to 3 inches long. I'd be making the parts using traditional model engineering practices rather than using actual...
by picnic
Sun Nov 08, 2009 8:09 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Some success
Replies: 1
Views: 4150

Some success

Just completed my second hot air engine (the first wouldn't run :( ) and here are a couple of pics. It's to my own design, a shameless cobbling-together of various other engines I've seen on the net and I've almost finished drawing up the plans. It's water-cooled has a 9mm dia power piston and 12mm ...