Comments on: Jan Ridders’ New LTD Stirling Engine http://www.machinistblog.com/jan-ridders-new-easier-to-make-ltd-stirling-engine/ Plans, projects and how-to's for home machinists Sun, 05 Feb 2012 23:24:11 +0000 hourly 1 http://wordpress.org/?v= By: Rob http://www.machinistblog.com/jan-ridders-new-easier-to-make-ltd-stirling-engine/comment-page-1/#comment-18589 Rob Fri, 11 Mar 2011 17:31:42 +0000 http://www.machinistblog.com/?p=949#comment-18589 David, I have a suggestion for improving performance. I've been building a low-temperature-differential Stirling and it seems to me that you could greatly increase heat transfer to or from the air inside the displacement cylinder by adding fins on the inside of the cylinder plates. Even if the fins were very small they would still greatly increase the amount of surface area in contact with the air and therefore the rate of heat transfer. Simple fins could be manually machined without much difficulty. And if you have access to CNC equipment you could easily make much fancier and more effective ones (even artistic looking fins). Most high temperature Stirlings have external cooling fins on the cold side but I don't know if I've ever seen a LTD Stirling with some. Whether they would help much on the hot side would depend I think on what kind of heat source it was designed to use. Rob R. (Editor) David,

I have a suggestion for improving performance. I’ve been building a low-temperature-differential Stirling and it seems to me that you could greatly increase heat transfer to or from the air inside the displacement cylinder by adding fins on the inside of the cylinder plates. Even if the fins were very small they would still greatly increase the amount of surface area in contact with the air and therefore the rate of heat transfer.

Simple fins could be manually machined without much difficulty. And if you have access to CNC equipment you could easily make much fancier and more effective ones (even artistic looking fins).

Most high temperature Stirlings have external cooling fins on the cold side but I don’t know if I’ve ever seen a LTD Stirling with some. Whether they would help much on the hot side would depend I think on what kind of heat source it was designed to use.

Rob R. (Editor)

]]> By: David Reeves http://www.machinistblog.com/jan-ridders-new-easier-to-make-ltd-stirling-engine/comment-page-1/#comment-17722 David Reeves Sat, 05 Mar 2011 18:12:12 +0000 http://www.machinistblog.com/?p=949#comment-17722 I am in my final semester in advanced machining technology.The Sterling engine is as present our current project.Some parts were made on a Haas cnc mill but most are being made on manual machines.We are making 6 of these machines,one for each student,one for our showcase and one for our advisor.We have been brainstorming on how to increase the horse power.This is a very interesting project. I am in my final semester in advanced machining technology.The Sterling engine is as present our current project.Some parts were made on a Haas cnc mill but most are being made on manual machines.We are making 6 of these machines,one for each student,one for our showcase and one for our advisor.We have been brainstorming on how to increase the horse power.This is a very interesting project.

]]> By: Rob http://www.machinistblog.com/jan-ridders-new-easier-to-make-ltd-stirling-engine/comment-page-1/#comment-10673 Rob Sun, 09 Jan 2011 03:08:33 +0000 http://www.machinistblog.com/?p=949#comment-10673 I came across a really nice builder's log of this engine with lots of photographs. You can find it on the MadModder forum - http://madmodder.net/index.php?topic=3433.0 I came across a really nice builder’s log of this engine with lots of photographs. You can find it on the MadModder forum – http://madmodder.net/index.php?topic=3433.0

]]> By: Bill Mitch http://www.machinistblog.com/jan-ridders-new-easier-to-make-ltd-stirling-engine/comment-page-1/#comment-5624 Bill Mitch Fri, 12 Nov 2010 15:44:29 +0000 http://www.machinistblog.com/?p=949#comment-5624 I just wanted to say that I run my LTD sterling engines on a Peltier CPU cooling module I got from Electronic Goldmine. It is powered from a 6 volt power source. I was going to use the cool side but after a while the cool side warms up due to no colling air on the hot side heatsink. So I use the hot side. I set the engine on the heatsink and it works great. I just wanted to say that I run my LTD sterling engines on a Peltier CPU cooling module I got from Electronic Goldmine. It is powered from a 6 volt power source. I was going to use the cool side but after a while the cool side warms up due to no colling air on the hot side heatsink. So I use the hot side. I set the engine on the heatsink and it works great.

]]> By: Murray Tricker http://www.machinistblog.com/jan-ridders-new-easier-to-make-ltd-stirling-engine/comment-page-1/#comment-1498 Murray Tricker Sun, 25 Apr 2010 23:21:44 +0000 http://www.machinistblog.com/?p=949#comment-1498 Re Jan Ridders coffee cup engine. I have just finished mine and are doing some minor tweeks to get it to run better. Re the displacer cylinder I bought a plastic biscuit jar (the ones with the compressable clip for sealing)NZ$5.00. The softening temperature appears to be about 150degC so dont overheat the bottom plate to coax it into life like I did. It is near enough to 100 mm dia but slightly tapered. Just need to machine the top and bottom plate grooves to an appropriate dia. I used silicon gasket sealer (the red one from the motor car spares dept.) From memory it has about a 300degC operating temperature. I basically cast my own rectangular "O" rings in the plates using this goo. The cylinder does not adhere to the plates using this method. Murray T Re Jan Ridders coffee cup engine. I have just finished mine and are doing some minor tweeks to get it to run better. Re the displacer cylinder I bought a plastic biscuit jar (the ones with the compressable clip for sealing)NZ$5.00. The softening temperature appears to be about 150degC so dont overheat the bottom plate to coax it into life like I did. It is near enough to 100 mm dia but slightly tapered. Just need to machine the top and bottom plate grooves to an appropriate dia. I used silicon gasket sealer (the red one from the motor car spares dept.) From memory it has about a 300degC operating temperature. I basically cast my own rectangular “O” rings in the plates using this goo. The cylinder does not adhere to the plates using this method.
Murray T

]]> By: Phil http://www.machinistblog.com/jan-ridders-new-easier-to-make-ltd-stirling-engine/comment-page-1/#comment-466 Phil Mon, 30 Nov 2009 00:46:27 +0000 http://www.machinistblog.com/?p=949#comment-466 Hi Folks, I ve just build my 1st stirling ltd based on some other plans. I had also bring my small contribution and new tips to finalize it since i had also a few problems with airtight at the begining like anyone.Relative to the "o" ring question, one must find several tricks to achieve it. You may depending the size u want get different materials ie for small ones a coca cola bottle (very strong) plastic ring.You can also use some Rhodid bands easy tu cut. Mine has been specially shaped into a 2 mmm polyglas (172 mm diameter)but is more tricky and takes longer to be perfectly manufactured. My first idea was to fix the 2 aluminium plates with some nylon screw with 2 silicon joins assuming airtight with a possibility to access again the inside motor to prevent maintenance of the displacer. Possible but difficult, further considering that any screw will create thermic bridges affecting the engine efficiency. Silicon sealing only, with a thiner as possible "O" ring despite u keep some efficient rigidity of the ensemble will give u the best result. I'll be glad to further help on any other question since i ve been first helped on my side. Good Work... Hi Folks,
I ve just build my 1st stirling ltd based on some other plans. I had also bring my small contribution and new tips to finalize it since i had also a few problems with airtight at the begining like anyone.Relative to the “o” ring question, one must find several tricks to achieve it. You may depending the size u want get different materials ie for small ones a coca cola bottle (very strong) plastic ring.You can also use some Rhodid bands easy tu cut. Mine has been specially shaped into a 2 mmm polyglas (172 mm diameter)but is more tricky and takes longer to be perfectly manufactured. My first idea was to fix the 2 aluminium plates with some nylon screw with 2 silicon joins assuming airtight with a possibility to access again the inside motor to prevent maintenance of the displacer. Possible but difficult, further considering that any screw will create thermic bridges affecting the engine efficiency. Silicon sealing only, with a thiner as possible “O” ring despite u keep some efficient rigidity of the ensemble will give u the best result. I’ll be glad to further help on any other question since i ve been first helped on my side. Good Work…

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