DIY variable speed disc grinder

[autogateman]

In my quest for flatness without a surface grinder, I bought a HF 12” disc sander a few months ago against the popular advice to not get a single speed. Well, although it’s orobably the most well made tool I’ve bought from HF, it removes material way too fast. I own a company that installs security gate systems and I come across small DC motors and gearboxes all the time and thought I’d try to build my own disc sander with one. I started off with this 1/2 hp 24vdc motor I got off of a used gate operator.
I then found an 8” disc sander disc on eBay that only needed a shaft bushing to fit on the motor.

 

[autogateman]

I found a power supply and PWM on Amazon and got them all wired up.

 

[autogateman]

The PWM has the speed control made in to the front and also has a brake.

 

[autogateman]

For right now it’s bolted to my bench top but eventually it will be on a stand. Total investment $60 and it works beautifully!!

 

[Ken H>]

Good job - Sounds like you did a good job.