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I purchased a Grizzly Buffer a few years ago and to save $$$ I didn't get the variable speed. It is a 220v, 1725 rpm model. Any suggestions on how to regulate the speed? Will a 220v dimmer work and are they even available?

Help would be appreciated.

Danny R. Little

No you can't use a dimmer to slow a motor. It will burn it up.

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http://goatrockukulele.com

If its a motor and separate pulley to the buffing axle, smaller pulley on the motor. If its an all in one, then use a smaller buffing wheel .. ... big difference in speed ....( remember circumference is pi x diameter, so % change in buff size equates to the same change in buff speed (inches per second of buff hitting the guitar)

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Tony Karol
www.karol-guitars.com
"let my passion .. fulfill yours"

Inverse diameter buffs will help. Induction motors are not generally speed controllable AFAIK. But, I have always wondered why one could not convert 60Hz to 30Hz to halve the speed. Apparently it is possible, but not cheap: http://en.wikipedia.org/wiki/Induction_motor

Since you are already $$ into this thing, one idea would be to use the motor to drive a 1:2 pulley system... (cut speed in half). Parts needed: 3/4" go-kart axel, threaded on both ends (one end reverse threaded!!), 2 2" pulleys, 2 4" pulleys, 2 v-belts (or link belts), 2 pillow block bearings and you are almost there (and a way to mount the shaft near the motor). Note that the doubling of torque will make this (already torquey) buffer dangerous for use with guitars. However, if you ever need to buff chrome bumpers, you still have the original buffer!

As you can probably guess, this will cost somewheres near $200. Another option (better) is sell the Grizz on CL, and start over. Get the SM system, or buy the shopfox arbor (Grizz) and grab a 1/3 hp motor from somewhere and you will get it all done for under $200.

Mike

The route I took was to find a used 3-phase motor which are normally cheaper than single phase.
I mounted the motor on a 2x8 board with an outboard bearing supporting a long shaft attached to the motor.
The VFD (Variable Frequency Drive) plugs into 220VAC single phase and converts it to 3-phase.
For folks not familiar with VFD's, they are a wonderful tool for motor control including soft start, variable speed, reversing, braking and many more programmable features. (Too bad that cyclone collectors and edge sanders are not offered with a VFD option)
I don't use the reversing feature of the VFD but probably should as reversing rotation and moving to the "back side" of the buffer would allow easier access to the various surfaces of a cutaway, for example. The advantage is that the guitar neck would be pointing away from the buffer shaft, I suppose.
But, on the other hand, a double shafted buffer offers the same option if running same grit on both wheels.
Nelson

How much do these controllers cost? Also, excuse my 3 phase ignorance, but are low hp motors readily available? (less than 1hp). I read where you could feed that device with single phase, but there were caveats. Is that what you do? Please elaborate. -mike

http://www.driveswarehouse.com/Drives/AC+Drives/Micro+VFD.htm?osCsid=8cbca2088c098020619b19504120a5c3

http://cgi.ebay.com/BALDOR-VM3603-1-HP-MOTOR-3-PHASE-NEW-/270633550811?pt=LH_DefaultDomain_0&hash=item3f030443db

The motor is too good of a buy at the current $11.50 bid. I'm sure it's going to go for much more.
It's just an example of what might be available on Ebay doing a search, for example, on "3 phase motor".
You can run a larger horsepower motor than what the VFD is rated for, just can't use all the HP.

Mike, you're right on the caveat and I believe it amounts to a power loss going from single phase to 3 phase.

Nelson

Thanks for all the advice. The buffer is a direct drive, not a belt unit.

Nelson, is the VFD device available as a single phase without the converter? What circuitry controls the speed in the variable speed Grizzly buffer?

Danny R. Little

Nelson, thanks for the VFD info. I did a quick search and found that Hitachi makes a single or three phase input model for a 2hp motor for $202. It seems that would fit the bill.

Thanks again.

Danny R. Little

I think most (all??) VFD's output 3-phase, so make sure to check the specs carefully. I do know that Hitachi makes VFDs that are 1-phase or 3-phase input with 3-phase output.

John

What John said.
I don't see the Grizzly Variable Speed Buffer in their online catalog.
Can someone point to it?
Nelson

I'll check the output specs to see if it is single phase.

Nelson, Grizzly stopped selling the big buffers in 2009(?). They offered them with a variable speed plus RPM digital readout or without the variable speed. At the time I thought the extra few hundred bucks seemed high. Now, not so much. I email Grizzly tech support to ask their advice. No response as of yet.

Thanks

Dan