Aluminum flywheels

[awJCKDup]

I'm building Jan Ridders Bas Sterling (great plans) which uses a brass flywheel, since these engines are low power, could you substitute aluminum for the flywheel and not effect the engines performance?
John

 

[portlandron]

Have not built that sterling but have built two others. What I have found is that because of the low power these type of engines produce you need the mass a brass flywheel gives to get them to cycle.

 

[shred]

I used Aluminum in my Stirling Bas (http://www.homemodelenginemachinist.com/index.php?topic=11911.0) and it works fine. I oversized the rim area somewhat, but it's not near the weight a brass flywheel would be. I was plotting to add brass inserts if needed, but they weren't.

If you look at Jan's pictures, he didn't use brass on all his either.

 

[awJCKDup]

Thanks gentlemen I appreciate the input. I had also e-mailed Jan and his reply was "You can make the fly wheel from Aluminium I think, less mass and so less inertia than steel or brass but it will work I think in this case." So I will Fiddle with it some more, before making a brass or steel flywheel. These engines sure seem to be touchy.

Thanks again
John

 

[Mainer]

If the aluminum proves to be too light for smooth running, you can always increase the mass by adding some uniformly-spaced brass slugs around the rim of the flywheel, assuming the appearance doesn't put you off.