1.This is a Free piston Stirling engine ，plz use Alcohol with a concentration greater than 95% as fuel

Because of the structure of the swing arm, there will be relatively large vibration during the operation, so please use your hand hold it or Fix the board on the table with glue

like this

2.It takes about a minute to warm up,plz do not Sprinkle water on the hot cylinder glass, it will break