[AiR_GuNNeR]

I've got my Teco 3hp VFD, so now it comes time for motor selection. Any reason this one would work fine?
https://www.surpluscenter.com/item.a...tname=electric

I know it won't be a drop-in and will require a shaft sleeve as well as mounting plate adapter, but other than that, are the specs ok for use on the square column mill?
Eric

[Al_The_Man]

Looks like a decent motor, handy having C face and foot mount, good price, doesn't say where it is made though.
You should be able to run up to 120hz.
Al.

[Runner4404spd]

you can get 56c cface motors on ebay up to 3 hp. i got a baldor motor tefc for about $90.00

[arizonavideo]

The IH CNC mill runs a 3450 RPM motor on the CNC.

That one looks like a 1750 RPM.

[BobWarfield]

If you're going to go to the trouble, I'd definitely get a 3HP rather than a 2HP. It isn't so much to use the full 3HP as to make sure you have torque when running below 60 Hz.

Cheers,

BW

[AiR_GuNNeR]

If you're going to go to the trouble, I'd definitely get a 3HP rather than a 2HP. It isn't so much to use the full 3HP as to make sure you have torque when running below 60 Hz.

Cheers,

BW

Hi Bob,
Thanks for the reply, as well as all of your past input on the IH mills. I was a bit concerned about the extra weight of the 3hp over the existing 1hp motor cantilevering out the way it does. If I get the 3HP, do you think getting a 3400RPM motor would be a better idea, or stick with the 1700 and let the VFD bump it up to perhaps 3000?

[BobWarfield]

I wouldn't sweat the weight so much, and I would go for the higher rpm motor. You just can't have enough rpm for aluminum on these mills.

Best,

BW

[Cruiser]

Looking at the motor I see that the bolts come in from the underside of the lid to the motor, this is what I have and it will entail much modification to make it work unless you make a new face plate, If you make a face plate it will have to be low profile or you loose the intersection length needed to mate with the drive end of the gearbox shaft.
Also, being a four pole motor, you shouldn't have any torque issues, your gear box will take care of that just by going down a gear when you need the torque. If you have constant torque op with vfd that helps and if you have Hz overdrive it will help if going to 120hz to double RP M's. Mine goes to 400hz but I have set my limit at 120hz as it is not an inverter drive motor.

[Richard-TX]

Hi Bob,
do you think getting a 3400RPM motor would be a better idea, or stick with the 1700 and let the VFD bump it up to perhaps 3000?

If you run a 1725 RPM motor at 3450 (120 hz)you will lose some power unless you raise the voltage, but since you can't you are stuck. A motor is a v/hz device which means you can safely run a 230 volt motor at 460 volts provided you spin it at 120 hz. This is what the v/hz mappings in the VFD do. They reduce the voltage applied to the motor at lower speeds. It would map higher voltages (greater than 230 volts) to higher (greater than 60hz) speeds if there were more voltage available.

If it were me, I would target the midrange motor speed at 60 hz and use the VFD to adjust within a moderate range. 20 hz - 100 hz or so.