[HaasStudent]

Hello, I've been working with the VF-4 in my shop for about two years now, and while I was drilling and tapping a Jig plate the machine began to throw the 123 Alarm: Spindle Drive Fault during the tapping cycle, at first it happened once in a row of tapping cycles, but then it happend a few times in one row.

Since then trying to orient the spindle, or turn the spindle in any way using its motor throws the 123 alarm. It has had problems in the past orienting the spindle before and sounded much like a post in this thread:

http://www.cnczone.com/forums/haas_m...3_spindle.html

To qote Haas__Man "Sorry dafowfidy,
I think i have misread your original post. Could you confirm to me that your machine is a 1992 model VF2?
If it is then you do not have a vector drive. In its place then you probably have a Mitsubishi spindle drive or a yaskawa drive. When the fault happens look at the spindle drive unit, there should be a small lcd display, does it have anything on the display?
Also when you orientate the spindle does the spindle rotation look smooth? or is it jerky?
If it is smooth, but too fast for the locking maechanism to lock the spindle, then it is possible to slow this down with parameters. Parameters 72 and 73 are the speed of rotation of the spindle when orientating. One is for high gear. the other for low gear. if you lower the value, then you lower the speed of rotation and give the spindle lock mechanism a chance.
Hope this helps.
"

The spindle on my machine appeared jerky and somewhat slow when orienting, on the mitsubishi Freqrol-a200e-ul unit I am reading one of two codes when this happens, OC2 or OC3. Resetting the Haas, resets it so there is no error, but trying to turn the spindle only throws the error again.

[double a-ron]

Same thing hapenend to me on my MiniMill. It's either the encoder or the encoder belt or both.

[garylb]

i used to get this fault on my mini mill when i powered up and was told it was the power unit (vector drive). Turned out to be the spindle servo amplifier!

[HaasStudent]

So, we have fixed the spindle drive controller, but we are still concerned as the spindle when spinning up to any RPM is now hesitating at the beginning, as though it is fighting its own rotation, it was not doing this before the drive controller was replaced, and it is not throwing any alarms, but we are not running it in fear of breaking somthing else. Any insight to this?

[Haas__man]

The first thing to check is that the spindle drive is grounded properly. Make sure all groung leads are to chasis or ground - and have good contact.
What is the year of manufacture on the machine?
When you say you fixed the spindle drive unit - how did you do this and what was wrong with it? Did you remove the drive from the machine to do this?
Also - does the spindle load meter work correctly?

[Wizzard of H]

There are some things that should be cleared up here:
1) If this were caused by an encoder, you would get an encoder alarm because the encoders are self-tested.
2) In a mini-mill or TM, there is no box called a vector drive; there is an axis amplifier as they supply enough current for the smaller spindle motor.
3) Grounding is that old "easy to blame thing" but a lack of ground does not give this kind of symptoms. (A lack of ground WILL cause electrical shock!)
4) A hesitation at start could be caused by an open wire from drive to motor.

[HaasStudent]

I am working with the shop manager on this, so the best I can do is relay what I have been told to me.

The machine is a 1997 VF-4.

The Spindle Drive controller drive had the IGBT replaced, and with a slightly dissimilar model, we were assured by the Haas rep and Mitsubishi that it was compatible with our drive controller. The Mitsu. Rep had us change a drive startup parameter to try to fix the jerky spindle problem. The Controller was removed, torn down and the Blown IGBT confirmed and replaced.

The spindle Load meter reads about 110% on accel and when it has reached its set RPM never drops below 50%.

I have been told that the motor wiring has been checked (which sounds like a visual inspection) and nothing is corroded.