Well i thought it would be okay since it is not some wooden toy or something really out of steemhunt guidelines. it shows in fact how simple stirling engines work (A Stirling engine is a heat engine that operates by cyclic compression and expansion of air or other gas (the working fluid) at different temperatures, such that there is a net conversion of heat energy to mechanical work). Stirling engines were used and are still used today and i thought this might come under category 2-6. Innovative Engineering/Design Products. Guess im wrong. But since moderators approved it, i figured it is okay to post some different models of stirling engines aswell.
Yeah i am trying hard, so when stuff like this happen i try to get to the bottom of it so i won't make similar mistakes in the future :)