3Phase Drill Press and a VFD

[racingtadpole]

Bit of background:
Got a really good deal on a really old and sturdy 2MT drill press a couple of months ago. Only issue is that its 3phase and my house only has single phase supply. No problem, I go get a VFD and use that to make it run. Dragged it out of storage on the weekend and decided to have a crack at making it work.
So having looked at the VFD and the motor on the drill, I have a problem. The motor is wired in Delta configuration, VFD needs the windings in Star configuration. The motor can't be changed from Delta to Star without sending it to a rewinding company to have the far end of the windings fished out.

As I see it this leaves me with three options.

1 Send the original motor to the rewinders and have the windings reconfigured. This will allow me to maintain the original pulley and use both the pulleys and VFD to control the speed.

2 Buy a cheap three phase motor off evilbay that already has the windings that can be configured to run in Star and use a fixed pulley around the mid range of the original speed settings. Use the VFD only to control the speed.

3 Buy a single phase motor with a larger shaft than the current 3 phase motor and bore the pulley to suit the larger shaft size and use it like nature intended.

Options 2 and 3 cost roughly the same, option 1 is more expensive.

Im leaning toward option 2 because the VFD gives me more control over the speed than six different pulley settings will, and I already have the VFD.

What say the learned folks of Garage Journal?

 

[454ragtop]

I have VFD's on a couple drill presses, and a couple more on lathes. Not sure what thia star delta thing means, but any VFD I've ever seen just outputs 3 power leads and a ground, long as motor was the correct voltage it would work. Are your motor and VFD for the same voltage?
Jim

 

[marineengineer]

I think the Star as you call it is actually a Y connected VFD. If this is true you shouldn't have any problem running the motor. That is the internal wiring in the VFD. The output is essentially 3 phase as long as you have the 3 power phases and a ground for both the motor and the VFD you should be all set, as long as the voltages are the same. If it is an Electronic VFD there might be a setting to change the internal wiring. ex switch or button. Im not sure of the one that your working on but what i've mostly seen is an electronic VFD with a with a diagram to set it up for what ever you need. Ive never seen a Delta or Y specific VFD, not to say that they don't just ive never seen one. A picture of the wiring name plate/schematic for both the motor and VFD would be helpful.

 

[930dreamer]

Here's some interesting reading, but I don't think it will answer your question.

http://www.allaboutcircuits.com/vol_2/chpt_10/5.html

 

[ndnchf]

I've got a Walker-Turner WT 900 I restored. I put a Baldor 3 phase 220v, 3/4hp motor on it and a TECO FM50 VFD. The motor was a freebie, I cleaned it up and, put in new bearings and fresh paint. Its good for another 50 years. With the VFD it runs fine on 110 house current.

 

[Mgraves235]

Whats the make/model of the drive you're using?

The drive shouldn't care, or know, whether the motor is Wye or Delta, provided the voltage levels are right.
You're going from 240 to 480, i assume?

As far as the pulleys, you will probably want to retain those to control speed, as there are mechanical advantage issues to deal with and not being an inverter duty motor, the original motor will put out peak efficiency and torque near it's synchronous speed.

 

[camarotoolman]

Just find a good used motor and get a new step pulley at a hardware store.