LTD Stirling Engine

A low-temperature difference Stirling engine I built for a friend.

Plate diameter is about 170mm. The flywheel is a bicycle disc brake,
which looks great because of the hole pattern. The displacer is
building insulation foam. I used a graphite bearing on the displacer
rod and a graphite power piston in a glass cylinder. The main shaft
and bearings are taken straight from a small stepper motor.

This is running from a small bowl of boiling water placed underneath.
It takes about 10min for it to reach temperature because of the large
mass of the aluminium bottom plate, but it runs happily once it's
up to temperature.

There's no sound on this video because it runs too quietly for the
camera to hear. It's a gentle "tick-tick".

Hope you enjoy! For high-res photos, see http://www.flickr.com/photos/48329631@N08/sets/72157624130434409/

Category:

Science & Technology

Tags:

• LTD
• Stirling
• engine
• low
• temperature

[robyh12]

Do you know any website to buy precision borosilicate glass tube?

[imajeenyus42]

@robyh12 The only source I can think of would be gas syringes - these are typically precision-ground and achieve a gas-tight seal with no need for grease or a sealing O-ring. Not the cheapest (I think £20-£30 for a single syringe), but you might get two or three cylinders out a single syringe. EBay'll probably have second-hand ones; search for "gas syringe" or "ground glass syringe"

[ashwin1111111111]

what is filled between the cylinders ??? air ??

[imajeenyus42]

@ashwin1111111111 Yes. The displacer moves the air between the hot and cold plates, causing it to expand and contract regularly, pushing and pulling the power piston coupled to the flywheel.

[MojaJinonice]

Can You tell me where did You buy the borosilicate cylinder and the graphite power piston? (or graphite piston in a pyrex glass). I live in the Czech republic and I could not find the commercial source of precision glass tube and graphite piston as well. Thank You for Your answer.

[imajeenyus42]

Thanks for your email! I made the cylinder and piston from scratch. The cylinder was made from glass tubing. It was cut roughly to length, and then the ends were ground in the lathe with a diamond cutter mounted in a Dremel rotary tool.

The piston was machined from a solid chunk of graphite I had lying around. I faced, drilled and tapped a small piece, then mounted it on a threaded mandrel and turned to size. I hope that helps! Please ask if you have any more questions. Best regards, Lindsay.

[robyh12]

Yours is rellay good.Running perfectly.Great job mate

[robyh12]

Thanks for your answer.I also built an LTD stirling.I have mini lathe.Just the glass tube is difficulte to get.

[ffblog]

very nice idea for the flywheel!

probably I copy it 

[MojaJinonice]

My problem is, that I didn’t find a commercial source of graphite in the Czech republic. The same problem will be probably with precision glass tube. Some of people use a body of glass medical syringe, but in this time all of them are made of plastic (not glass).

[MojaJinonice]

Thank You very much for such a fast reaction.

You must be a very skilful man. By the way, the idea of using a disc brake as flywheel is a little bit “revolutionary”. I have never seen to use this element (disc brake) in any construction of LTD Stirling engine here on You Tube (nor on Internet at all).

I wish You a lot of inventions by construction of LTD Stirling engines.