Good morning all, I just wanted to chime in to this convo and bring up a few talking points.
I'm actually in the same boat as the OP. I have a small parts lathe, which I use daily for my business. The controller dies religiously once every 12 months. At the moment, I'm looking at 12 days down time while waiting for a replacement controller to arrive, which is unacceptable. I have orders that need to go out yesterday.
I have a 480 3 phase motor and inverter that would be perfect for my application, a SEW Eurodrive...$4000 of motor for a $1000 lathe, but I cant use it until I get 480 3 phase into the shop. Would be great as the inverter is an explosion proof sealed unit that can provide excellent torque at 1RPM, but I cannot satisfy the power requirements at this time.
That being said, I am looking for alternatives to replacing my motor controller every year. Someone said use a treadmill motor/gearbox/controller. That seems like a very realistic alternative as you can still receive a decent amount of torque at low RPM's while not risking burning out the motor. I noticed a lot of folks here are recommending VFD's. I cant help but notice that not much attention has been drawn to the fact that you drop the RPM's too low(reduce the Hertz) you will burn out the windings in your motor. While the VFD solution may be fine and dandy for folks who keep their RPMs up, I typically run at 80 RPMs. Super slow. If I were to try and use a VFD to operate a motor that wants to run at, oh, I dunno, say 1000 RPMs, and dropped it down to what I need(80), I would burn out the windings in my motor. Not only that, but lose torque. So, anyone correct me if I am wrong, but a VFD is not going to be a permanent solution for me. I'm thinking something like a treadmill motor with a reducing gearbox would be best to maintain the motor torque and still provide the motor RPMs I need.
But the single phase motor that I have and am currently running at low RPMs does not seem to be experiencing any issues. This motor is 120VAC, controlled by a small PCB with a potentiometer. The motor isn't the part that is burning out...it seems to be the controller. There are 2 black wires and 2 white wires going to the motor, then 3 ground wires going from the motor controller to the lathe chassis. I have to wait 5 more days before my new controller gets here, but the symptoms I am experiencing are the exact same as those I experienced last time I had to replace my controller. I will update when I install the new board, but it seems to me that the motor is still fine and the controller is burning out. Always seems to go out in the winter time, and the lathe is in an un-heated shop so the electronic components of the PCB might be failing due to freezing temps. I would definitely be interested in hearing anything anyone else has to say on the topic.
Regardless, I just wanted to throw in my 2 cents, and would welcome any knowledge any of you might like to share. Still trying to find a cost effective solution that will not require me to replace parts every year. I have two conveyor belt motors with controllers but I am not sure what their power requirements are. I can do 230 3 phase, just not 480. I also have extra 120 single phase to 230 3 phase VFDs. It's just going to take me too much time to make the mounting, program the control, and wire up all the parts when I can just spend another $160 to get another controller and work for another year.
Thanks for reading!
