We like it when hacks are literal hack jobs, put together with what’s on hand to do a specific job. This quick and dirty angle grinder circle cutter certainly fills the bill, and makes decent cuts in sheet metal to boot.
The build starts with an unlikely source for parts – an old automotive AC compressor. The one that [Made in Poland] chose to sacrifice was particularly nasty and greasy, but after popping off the pulley, the treasure within was revealed: the large, ring-shaped clutch electromagnet. Liberated from the compressor, the electromagnet was attached to a small frame holding a pillow block. That acts as an axis for an adjustable-length arm, the other end of which holds a modified angle grinder. In use, the electromagnet is powered up by a small 12-volt power supply, fixing the jig in place on the stock. The angle grinder is traced around and makes a surprisingly clean cut. Check out the build and the tool in use in the video below.
At the time [Made in Poland] recorded the video, he noted that he did not have a plasma cutter. That appears to have changed lately, so perhaps he’ll swap out the angle grinder for plasma. And maybe he’ll motorize it for even smoother cuts.