The 3/4 horse power universal motors used in washing machines are an abundant source of power for all kinds of workshop tools, from a small lathe to a disc sander The problem is we can't just hook them up to their rated voltage without some kind of control circuit. At no-load speeds the motor goes so fast it damages itself.
In the past I have used a few different control circuits to control these motors. The most recent is used in the multi purpose rotary tool I have been making http://machine.construction/rotary_tool In this I use a closed loop Arduino based circuit that uses a PID algorithm to try and match your desired set speed, with the actual measured rpm of the washing machine motor. This was a relatively complicated circuit, and in the video I show how to make it and compare it to the more simple triac based circuits.