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 ...

Angle grinders and cut-off tools might seem like the same tool ... making them easy to operate with precision while the wheel spins and chips away at whichever material you aim to cut or grind.

long piece of 2×4 aligns the tool to the wheel just right. For other bench grinders, you may need to adjust this length. Note: The angle you cut on the block is not the same as the tool’s bevel ...