My Grizzly lathe speed control didn't work as well as I thought it should (sort of like the Delta lathe I used in high school 46 years ago. I was using variable frequency drives at work & thought one might be the ticket to making the lathe go slower & be more user friendly.
And it was all that & more !
I can operate the lathe at about 60 rev./Min. & reverse it while going forward without a trip or explosion ! It just ramps to a stop , then ramps into reverse. It has slow start. I liked it.
Later I thought a another 3 phase motor on end with a arbor would be nice, so I could put on various leather strops & white alum. oxide wheels etc. & grind on their face (which is a NO NO at high speeds) I propably operate it at 3 rev./per second. That can't blow up even if I were to wear through the wheel. This operated on a 3 pole 2 throw sw. & was great!
Recenthy I wanted a 3 phase motor on the end of the lathe, so I put a twist lock plug on the sharpener cord. Now I can also run a wire wheel by unplugging the sharpener & plugging in the wire brush motor.
It's GREAT !
Newer drives have alot more features.
Whai is a drive?
Drives take AC power convert it to DC power & put it on the bus inside the drive. The drive is a computerized motor controller and makes 3 phase variable frequency output. Zero frequency = zero speed. 60 HZ = full motor nameplate speed. The operator can control the drive from the key pad on the front of the drive or wire these functions to an external location. Drives can be purchased with single phase inputs or 3 phase inputs (fed from 1 phase sources they must be derated) Drives can be purchased in 120 vac, 240 vac & 480 vac
Motor Hp is amps x volts (1 HP=746 watts)
The 3 phase Delta unisaw was made in 2HP (746 x 2 =1493 watts)
If I fed it 120 volts x 12.4333 amps = 1493 watts
If I fed it 240 volts x 6.221 amps = 1493 watts
2 horse power still needs 1493 watts.
A really cool thing is that slow start doesn't draw 5 times full load current when starting. For instance you have a tool (maybe a compressor) in an out building & the feed to the building is adaquate for running but not starting. Slow start limits current draw & the compressor might be fine.
Drives have been around since the early 1980's & I have my first one--an early 1980 drive on my wood lathe. I put a drum controller on it for reversing (the newer ones have a the sw. on the key pad) I put a 3 pole double throw selector sw. on it to select between the lathe & the horizontal sharpener. Then I wanted a wire brush on a arbor shaft so I put a twist lock receptical & plug setup on so the sharpener could be unplugged & the wire brush motor plugged in. Switching isn't done hot.
1 drive 3 machines ! The drive manuals are found on line. Most large electrical manufacturers make drives & most motor manufacturers sell them under their name. But NEW they cost. I buy used & love them.
Drives are great! I think they should be standard on lathes & drill presses- sharpeners too.
Some people are afraid of electricity. In 1900 people tried to stop the use of it - said it was too dangerous to have in homes ! But then we no longer live in caves either.
I don't advocate the use of them by people without understanding them but you can learn if you want or get help.
Cheaper drives are available. Industry drives have tons of features that a wood worker would not use.
One useful feature is the electronic overload - Trips the drive & not the fuse
protects the drive (that saves the investment)
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