VFD Balancing?

[Edster]

I'd like to balance the VFD on my Fadal VMC15. I have the manuals from the fadal website. My machine is a 94 and the procedure in the manual doesn't match my VFD. Does anyone have a copy of the procedure for an older mill? The particular manual I have also says that in order to have rigid tap you need a vector drive. I hope that is just for the newer mills otherwise something is amiss because I have a Baldor SWEO Drive and rigid tap.

Any info would be appreciated.

[Al_The_Man]

Do you have an encoder on the spindle back to the VFD? Otherwise you will not be able to rigid tap. Vector drives have the capability of encoder or pulse wheel sensor input.
Al.

[nervis1]

Your Baldor drive should have a keypad on it. If not you can get one from Baldor for about 100 dollars. The procedure for balancing is in the manual off of Fadal's website. (Maintenance manual).

[Edster]

I have the keypad, and the manual off fadal's site. When I start to go through the steps to balance the drive the screen's don't match up to what's in the manual.

When should the drive be balanced, and what happens if it's not balanced?

[Al_The_Man]

If the drive is not balanced the ±10v analogue voltage is not set to zero for the drive at zero speed.
IOW the drive has to be at zero speed when the control is outputting a zero speed signal, otherwise it will creep . This is important with the rigid tapping feature.
Al.

[nervis1]

Next thing I would do is contact Baldor, their tech support is great, at least every time I've called them. I bet they will fax you the instructions.

[Edster]

I contacted baldor and got the correct manual emailed to me.

Next question. In the manual it says the motor should be free to rotate with no significant load. Does this mean remove the drive belt and let the motor spin free when auto tuning the drive?

[Al_The_Man]

Generally auto-tuning exercises the armature of the motor slightly, not at high speed or acceleration so as long as the load is not super heavy or operate into a gearbox in low gear then it really does not matter, as long as it is able to turn freely.
Al.

[Edster]

I ran the auto tune with no problems. Baldor said to remove the belt and run the auto tune. The machine is running better, but I'm still getting a C axis fault motor overload while rigid tapping. It's an intermittent problem, and 1 out of 10 tap cycles will get the fault. It usually faults out right before the tap cycle starts when the machine is setting the spindle speed. If it gets the 4 turns to set the speed right it will tap perfect. Are there any adjustments that need to be made to the c axis card?

[Al_The_Man]

It sounds like you have a separate motor for the C axis instead of using the VFD for tapping?
This would make sense if you don't have a vector style VFD for zero speed operation?
Or is this C axis card in fact controlling the analog to the VFD?
Al.

[Edster]

I only have one spindle motor, and I'm pretty sure there is a card for the c axis. Are there any adjustments for the c axis like the xyz?

[dango]

o.k. I will try to help you
first you need to find what type of control you have -2 or -4
it can be written on the paper inside the pocket of the door in the electric cabinet that
mount from the side
also you have to check if from the spindel card you have cable conector that goes
to the baldor the card is thired from write hand
thired check in SETP
what written for the gain and the ramp
if the control is -4 it written on page 2