The Hum-B™ edge grinder is ideal for grinding or polishing concrete, terrazzo, or stone surfaces, or removing adhesive, paint or epoxy coatings. ... Flex Shaft Machines . Flex Shaft Machines 3 - EG-EA 1-1/2 HP, 115/230v, 3450 RPM, Single Phase Motor with Changeover Switch, 7 FT Shaft and Housing, Tripod Base with Caster and 1:1 Ratio …