Hass VF-0 Spindle Drive Fault Q's, HELP!

[Ryan Moore]

Hi, I am new to the board and need help bad. I have a 1994 Haas VF0 and today the spindle drive fault is keeping me from cutting metal. The spindle comes on and runs fine at all speeds, but then when I turn the spindle off, or reduce the speed, Alarm goes off. Its not hot yet, fans are working, actually, all the covers are off right now. I can twist wrenches and fix machines all day long, but when it comes to electrical problems (that jiggling wires wont fix), I'm useless. Any help would be apreciated, I can't afford a tech to come out, and this machine is my source of income. Thanks!

Ryan Moore

[Geof]

This sounds like an open circuit on the braking resistor. That is the thing inside the cage on top of the machine that gets hot.

When the spindle slows down or stops it does it by rgenerative braking and the controller dumps power onto the DC buss. When the DC buss voltage goes above a certain level the braking resistor, also called the regen resistor is brought into the circuit to bleed off excess voltage. I think there is a relay somewhere that is supposed to close.

If, for some reason, the circuit to the regen resistor does not close the bud voltage goes up and triggers and overvoltage alarm.

[Ryan Moore]

Thanks for the responce. It makes sence to me, but how can I diagnose and fix the problem?

[timan]

Call your local Haas Dealer they are usually real helpful in fixing problems over the phone. If not call Haas Automation 1-800-331-6746 ask for Vertical Service and they could help you. If you need help finding your dealer ww.haascnc.com on their site they have a dealer locator.

[Ryan Moore]

Well, I called haas and they stepped me through some diagnostics and come to the conclusion that the Regen Resistor is bad. It read 20 ohms at the spindle drive and should only read 15. The bad news is they want 400 for a new one. Is there any way to repair it?? They also wanted 140 for a 35 dollar gates timing belt on the spindle, so I already know I'm getting shafted!

[Geof]

On my machines the regen resistors look for all the world like the elements on the top of your stove. If I ever need to replace any I will certainly go to the appliance parts store first with my ohmmeter.

[Wiseco]

Agreed with Geof

[timan]

Originally Posted by Ryan Moore Well, I called haas and they stepped me through some diagnostics and come to the conclusion that the Regen Resistor is bad. It read 20 ohms at the spindle drive and should only read 15. The bad news is they want 400 for a new one. Is there any way to repair it?? They also wanted 140 for a 35 dollar gates timing belt on the spindle, so I already know I'm getting shafted!

Take the numbers off of your gates belt to your local automotive store and cross it over. I had a operator error and lost a belt on a Saturday took it to the Local Napa and they fixed me right up!