Guy I met made his ac drive totally variable using a "Bridge"

[DMS]

Is this what you're talking about, using a bridge rectifier to go from AC to DC and give it vs? Would this method work to to run a crossfeed on a lathe or mill if you have the appropriate size DC motor? Would the dimmer cut down the power going to the DC motor enough to reduce its torque at low voltage? Not sure how all this works but trying to figure it out.

http://www.youtube.com/watch?v=LtXtmVV1kjY

thanks, Brian

It will work, but couple things to keep in mind. First is that those light dimmers are not meant to work with motors, so you will not be able to run them at full power. The other thing is, it will slow things down, but speed will still vary with the amount of load on the motor. I have used the same combination to run a small (1/8 hp) gear motor, and it works just fine. For a cross feed, you may also take a look at BillGruby's power cross feed build for the 9x20 lathe.