Thread: harbor freight bench buffer?

How about the smaller one:

3" Mini Tool Grinder/Polisher

I like the shielding.

The shield would have to come off if you want to buff with it. I would get at least a 6 inch wheel, JMHO.

to very the speed you could try wiring in a light dimmer switch. I picked up an old grinder from a flea market, with a little work and a dimmer switch i have one with speed control for about 15 bucks

I have a variable speed buffer that tops out at 1750 rpm. I would personally not use a faster one due to the safety issues if it pulls the blade from your hand. If 1750 rpm cant do it, I left the grinder or sandpaper too early.

Originally Posted by scotishcavalir

to very the speed you could try wiring in a light dimmer switch. I picked up an old grinder from a flea market, with a little work and a dimmer switch i have one with speed control for about 15 bucks

Yes, but the chances are good that if you drive it at low rpm you're going to burn the engine coils. Light dimmers work by chopping the sinewave and AC engines are really not made for that. The rpm to AC frequency is locked. If you chop the sinewave, you simply remove a lot of input power, causing the AC engine to 'skip beats' because it doesn't have enough power to keep up with the frequency. If you put some load on the buffer, you decrease the elecrical resistance and risk burning the coils.

Your other household appliances might also experience some interference because the dimmer shorts out parts of the sinewave, causing current spikes on the net which might be harmful or just cause a lot of noise.

Ah, that old electrical engineering magic!

So how do variable speed buffers do it?

Originally Posted by joeuke

Ah, that old electrical engineering magic!
So how do variable speed buffers do it?

Usually with a modification of a created three phase current or...they have brushes and are AC/DC motors. There are ways to wind a motor that can have speed change results also.
Basic_electric_motor_drive_alternatives
~Richard

I found out from a salesman that when you are ordering a 3 phase motor, you need to let them know because some motors are designed for a VFD & some are not. There wasn't any cost difference, but what do I know...I just took their advice. What I do know is that I can slow my grinder down to somewhere around 2-3 feet per second & it still has plenty of torque

Thats the buffer that i use and i like it! BUT! Buy quality wheels... From sears for example... The ones from harbor freight are trash! I also got a cheap belt grinder from harbor for my scales! Works great!

Yes quality wheels spiral sewn for Greasless loose for final buff, at least 2 sewn for each grit 3 in for the HF buffer.

I buy Caswells for wheels and greasless.