Need Help!- TM-1 Spindle Drive Fault Error ?

[AMCTony]

I have a strange error that showed up 2 times for no reason recently. 123 spindle drive fault. Once on start up and once on accel to full RPM several weeks later. After I cleared the error the machine worked fine. Any ideas as to what is causing this. Another thing is when the machine brakes to 0 rpm it makes a "brakes squeeling sound" as I could best describe it. Could this problem be due to sticky grime in the belts and the error coming from wires that this grime got into at the connections? I replaced the power supply in september so that should rule out that issue.

[AMCTony]

More Info: I can reproduce the problem by running up to max RPM and then hitting stop and going to max RPM again as soon as the spindle stops. Usually takes 3 or 4 times of doing that but sure enough it will give me error 123. Could this be a servo amp that drives the spindle, mocon board, Encoder on the spindle?

[Haas__man]

The fault could be one of three things:
320v power supply (spindle drive)
servo amp
regen resistor pack

Its very unlikely that the fault is encoder related or wiring related or belt related.

Hope this helps.

[Donkey Hotey]

Haas Man has already spoken. In the Vector Drive models, that's a Vector Drive fault ($3500). You don't have a Vector Drive. Yours uses a 320V power supply and a drive amplifier similar to the axis amps but, probably higher amperage.

I'm going to guess a bad spindle amplifier. There's nothing in the 320V power supply but a rectifier bridge and big capacitors.

How comfortable are you in working around deadly levels of DC voltage? There are a couple of checks you can do with a decent voltmeter. I doubt anything will change though. All you can probably accomplish is to eliminate the regen resistor and the 320V power supply from the suspect list. I still think it's going to be the spindle amplifier.

Have you done a lot of rigid tapping or rapid starts and stops of the spindle in its life? I don't mean an average part. I'm talking about runs where the machine is doing nothing but rigid tapping for hours. I'm wondering if the spindle amplifier overheated the IGBT that switches the regen resistor.

[AMCTony]

Thanks for the tips guys. I replaced the 320 ps in september so I pretty much ruled that out. Talked to a customer of mine that is very familiar with servo systems and he also said that my problem sounds like a bad amp. Replaced the amp with a new one today and the problem is fixed. Of course my HFO said that this could be anything and that they should come out and look at it. Weekend rate with a tech coming to yuma, az would be $3500 to $4500 alone plus parts. Reality is that I could replace everything in the drive line for that much and yes I priced out all the parts (motor, mocon, amp, ps, belts, encoders.... everything). Figured that I would start with the most obvious and work my way back. So again, Thanks Haas man and Donkey and my servo expert buddy. My HFO on the other hand, well I can get pointers like that at any local Starbucks. Now only if i could get a servo amp and a latte at the same place.

[AMCTony]

BTW,

Most of the stuff that I do is with small tools and quite a few tool changes. 0 to 6000 rpm to 0. Not a lot of tapping though. cycle per tool often is 20 seconds. then stop and next tool.... repeat.

[Donkey Hotey]

You might keep an eye on how hot the regen resistor gets during a typical run of parts. That'll give you some idea how often and how hard that circuit is working.

The Vector Drive machines have a big ol' heat sink and fans to keep the heat under control. The TM machines only have that spindle amplifier and I don't think they have quite the same cooling capacity.

Again: my guess is that the cycles you're running might be particularly hard on the IGBT that switches the regen resistor in and out. If the board doesn't get enough airflow and that guy overheats, it might destroy itself.

My hypothesis is not based in any real experience, just an educated guess. For all I know, that machine might run flawlessly for the rest of its life. Lets hope that's how it works out for you.