Power Tool Speed Controller

[YetiWoodz]

Variac Amazon.com
Variac Amazon.com
Best option at $50-$80 depending on Amp rating. It will vary the speed very well.


Variable Fan Speed Controller link
This is a cheaper option for $18. Its used for fans, but it will work for any AC motor that draws no more than the rating 120v 15 amps. Works best on motors that draw closer to 15 amps because the slowest setting only goes down so far. It doesn't slow down my 3 amp bench grinder, but works well on my 7 amp angle grinder.

 

[Axl Myk]

A rotary light dimmer is not designed to handle the current that power tools use.

 

[YetiWoodz]

A rotary light dimmer is not designed to handle the current that power tools use.

Ok, good to know. A variable fan speed controller is the other option, they are rated for certain amps, this one is up to 15amps on 120v.
Amazon.com
Actually that's easier, no modifying required, just use it like any extension cord.

 

[YetiWoodz]

I changed the first post so its the right product.