I want to start machining steel on my benchtop cnc, and I was wondering what people are using for coolant systems and chip evacuation for their desktop/benchtop units.

First thing I made with the CNC was a suds pump, wanted a DC motor so I could control the flow with a convenient knob on the panel. All the commercial units I found used AC motors.

I was worried for a while that the tool might come down on to a chunk of swarf, skate round on it without cutting and I would lose steps on the z axis but it simply doesn't happen.

I might brush or vacuum away the chips if I want to see, but it seems to work fine and dandy if I let them pile up. Heck it even works in the dark :D

I ended up up useing a Model airplane fuel pump in a recirculating system. I wired in a opto-relay that would turn the pump on when the spindal came on.