I have a 6 inch grinder rated at 3200rpms is this too fast for buffing?
Will it burn briar?
If so may need to look at making a speed control with a dimmer switch.
is 3200rpms too fast for buffing
Re: is 3200rpms too fast for buffing
Light dimmer switches are not meant for the type of load an electric motor poses. Chances are, you'll likely burn out the dimmer switch before too long.Boom wrote:If so may need to look at making a speed control with a dimmer switch.
Secondly, all a dimmer switch does is place resistance (impedance) in the line, reducing the supply to the motor. Slowing the motor speed this way considerably reduces the torque output of the motor. Years ago I tried a router speed controller, which can handle higher current loads than a dimmer, but it still reduced the motor torque way too much.
Other than a pulley system, there really isn't a workaround for variable speed on a single phase motor.
Regards,
Frank.
------------------
Grouch Happens!
People usually get the gods they deserve - Terry Pratchett
Frank.
------------------
Grouch Happens!
People usually get the gods they deserve - Terry Pratchett
- KurtHuhn
- Site Admin
- Posts: 5326
- Joined: Thu Nov 23, 2006 8:00 pm
- Location: United States/Rhode Island
Yeah, those router speed controls pretty much depend on the motor having brushes. Most grinders these days are brushless, and Ohm's law pretty much dictates that they operate at their intended voltage.
But, if you want variable speed, 3-phase motors and VFDs are actually quite inexpensive. People see "3-phase" and freak since they don't know what to do with it. Or look around for a 80-Volt DC motor and controller, they can be also be found very inexpensively.
Then there's always finding a junked treadmill. Those are DC motors, usually 2.5HP and 130 Volts DC. and if you find them intact, you've got your controller right there too. The amazing thing is, most folks toss out treadmills because they're big, bulky, take up space in their house, and they never use them - not because they're broken. These usually have a threaded shaft instead of a standard keyed shaft, but you can find pulleys with no problems if you need something other than what they come with.
But, if you want variable speed, 3-phase motors and VFDs are actually quite inexpensive. People see "3-phase" and freak since they don't know what to do with it. Or look around for a 80-Volt DC motor and controller, they can be also be found very inexpensively.
Then there's always finding a junked treadmill. Those are DC motors, usually 2.5HP and 130 Volts DC. and if you find them intact, you've got your controller right there too. The amazing thing is, most folks toss out treadmills because they're big, bulky, take up space in their house, and they never use them - not because they're broken. These usually have a threaded shaft instead of a standard keyed shaft, but you can find pulleys with no problems if you need something other than what they come with.
-
- Posts: 14
- Joined: Wed Dec 17, 2008 10:42 pm
- Location: buford , Ga
-
- Posts: 223
- Joined: Thu Jun 26, 2008 5:03 pm
- Location: pennsylvania USA
The speed of the buffer has a large effect on the quality of the finish. I recently obtained a variable speed grinder. Prior to purchasing the grinder i was mounting my buffs in a table saw that spins at 3500. Now I'm able to create a very glossy finish without any worry about the pipe being riped out of my hands.
-
- Posts: 14
- Joined: Wed Dec 17, 2008 10:42 pm
- Location: buford , Ga