So yeah, this isn'y anything fancy as I made it for a demonstration, this file includes:

Some low quality materials used for the demonstration, a small ~300 frame animation and the mesh.

This model was made based entirely on reading up on Stirling engine specifications and should work in real life, I will make a fancier version later ;)

Oh, and on the categories, engines are tools... right? (Oh and before I forget, Stirling engines make very potent generators therefore I think it fits in electronics as well)