I am not an electrician, I am sure there are codes against this…..Use at your own risk, ect, ect, ect.
This is the dimmer I chose, 600W push to power on so you can soft start your spindle and not torque the hell out of the machine.
Please use all the grounds, this might really save you. All the greens get wired together. Tuck it all back into the box carefully and make sure the wire nuts stay on.