I had heard so many people complain about the noise of the gears in a RF45-class mill that I planned immediately on converting to a 3-phase motor with a belt drive, even before I had gotten the mill. Of course, there are lots of other benefits, like variable speed and reverse, all controlled by the CNC computer.
After starting up the mill, however, I was very surprised. Maybe I’m accustomed to a different definition of noisy from being around woodworking machines for so long, but my first impression was how quiet the mill was, even at full speed.
So, even though my plans for a belt drive are on hold now, I went ahead and picked up this used Baldor motor off eBay for $75 and paired it with this Teco sensorless vector VFD. I want to learn about motor control anyway, plus I want to do a 3ph conversion on my drill press. Even the cheapest decent variable speed drill press is horribly expensive, but I can convert my Delta 18″ drill press to variable speed and still stay under $1000.
So, here it is, all hooked up! While it works OK, it’s really slow to start up and shut down. Also having problems reversing. I think I need to do some reprogramming of the drive. Note that the drive setting is actually 30.06 Hz, but I had my shutter speed too high to pick up the LED display properly.
Oh, and one other thing: The wiring is somewhat confusing because the drive is intended for multiple markets. The drive has inputs marked L1, L2, and L3. This drive has a 240V input, but the manual says to hook your incoming hot line L1 to the L1 terminal and your neutral to L3. Huh? 240V power uses L1 and L2, but not a neutral. They seem to be describing 120V service …
Well, the explanation is that the drive is intended for multiple markets and the documentation is incorrect for the US. Here in the US, L1 or L2 plus neutral gives you 120 volt, while L1 plus L2 (no neutral) is 240V. However, in other countries they only have 240V and they use an L1 and a neutral.
For the US, hook L1 to the L1 input and L2 to the L3 input, L2 is unused. Makes perfect sense, right?