Haas Alarm Problem

[BMackinnon]

Hi all,
This is my first post on here and Ive found some very interesting matl. as well.
But Im currently having a problem with my VMC. (VF-OE)
I was doing a simple interpolation with a .5" carbide EM (I wasnt working the mill hard either) but i noticed the spindle load was creeping up to 50%. So I waited till the tool was done in the hole and stopped it to look at it. I realized there was a chipped tooth so I decied it was time for another tool. When i went to hit reset and send it home there was 2 alarms 1 was #102 .. servo's are off yada yada and #163 ... Z axis drive fault. Now the spindle is stuck about 9 inches from the table and I have no idea how to relieve this.
I know on my mill that the Z servo switch can work its self lose after time but I have no way of removing the head cover with the head being down so low. It is hitting on the SHCS that attache the guides of the head.
So I guess I have 2 questions ... is there a way to relieve the alarm ? and dose it seem logical to remove the guides that run all the way up the colum of the machine so I can remove the SHCS that are in the way of the head ?

any help would be great .
Thanks
Brad

[Geof]

You should be able to turn the power off and then back on. Do not hit Auto Restart, go into the Settings and find Jog Without Zero Return and turn it on (right arrow I think). Now you should be able to jog your Z axis up. It is a good idea to go to the Current Commands screen so you can see the servo load and make sure you don't try to jog past a hard stop.

[BMackinnon]

yeah I went in today to try that and she stil wont move. I can't move any axis cause with that alarm the servos are still off and will not turn on for any axis to be able to jogged. I contacted Serco Machining (Haas Tech Support) but that will be a week till they get back to me. I have an electrician coming to test the servo motors and grounds. Then go from there.

[Geof]

Originally Posted by BMackinnon It is hitting on the SHCS that attache the guides of the head. Brad

Are you referring to the cap screws that hold on the bars on either side which retain the sliding way covers? I think you can take them off without anything coming loose except the way covers.

But based on your descriptions here is something I would try.

Get a screw jack and put it between the table(vise, whatever) and the end of the spindle. You might need to have a piece of heavy wall tube or something over the cutter.

You don't give the age of your machine but older Haas have a hydraulic accummulator and cylinder to balance the Z axis weight, later Haas have a magnetic brake on the ballscrew.

With the hydraulic balance I would just start trying to carefully lift the head with the screw jack.

With the brake style you need to get power to release the brake. I think you can see the brake on the end of the motor to find out what it needs. It will be DC and probably in the 90 volt region I expect. You might be able to get into the brake directly to give it power or you may have to find the correct wires in the control box. They are fairly easily accessible and I think they are labelled.

With the jack in place taking a small load and maybe a bunch of pieces of wood placed so it is impossible for the head assembly to drop, apply power to release the brake. I know that if this brake gets power when the servoes are off the Z axis will drop. There should be no reason why you cannot lift it with power applied to the brake.

In both case you need someone watching the ballscrew to see if it starts backdriving. If you don't see any screw rotation by the time you have put maybe a 1000 lb push on the jack I would say you are hooped but given what I say above about it dropping if not supported I expect you will be able to jack everything up.

[HuFlungDung]

Brad,
It might be worth taking a look at the axis drive amplifiers when you have the machine powered on. See if you have some LED's on, or not as an indication that power is getting to the amplifiers.

History: I used to have the odd spurious fault where I would see an Z axis drive fault alarm, unless I was using the A axis, in which case the fault was the A axis drive fault. It turned out that I had a weak and failing power supply to the drives. Not the main power, but a small standalone one that feeds 12v in there someplace (on a '96 VF3). Anyways, the alarm codes did not really mean what they said, it was simply a case that that power supply had failed, and the Haas interprets the dead amp fault as an amp fault, not as a failure of this little power supply.

If it is that one, I was able to source an inexpensive exact replacement through Newark electronics.

[BMackinnon]

Yes that is what Im reffering to. I didnt know if it would be a good idea to remove them or not, but it seems like the only way I can lift the head.
And it is a gas powered counterblance on my Haas not a brake. I thought of jacking it up that way to but didnt know how it would effect the counterblance.

Quote : It might be worth taking a look at the axis drive amplifiers when you have the machine powered on. See if you have some LED's on, or not as an indication that power is getting to the amplifiers.
I tryed that too this morning. That was one of the things listed in the service manual and I opened the back turned it on and no lights were visable on the amplifiers that were stated in the schematics of the machine.
Im assuming and hoping that it is some dumb electrical thing, cause I wasnt under any hard machining and the spindle was only spinning 3200 RPM, like I said I wasnt working it hard at all.

[Geof]

Originally Posted by BMackinnon .....And it is a gas powered counterblance on my Haas not a brake. I thought of jacking it up that way to but didnt know how it would effect the counterblance.......

It won't; you jacking it up is no different than the ballscrew pulling it up. With the counterbalance jacking is a much more viable option because you are not dealing with as much weight.

The only way I can imagine running into problems with jacking is if the servo motor is mechanically locked because something has broken. This is not impossible, I just checked alarm 163 in a Haas manual (bedside reading Hu ) and it reads: Current in servo motor beyond limit. Possibly caused by a stalled or overloaded motor. The servos are turned off. This can be caused by running a short distance into a mechanical stop. It can also be caused by a short in the motor or a short of one motor lead to ground.

[HuFlungDung]

Okay, what sounds a little different about your situation is that the spindle load was showing some sort of load error, which I presume might not have been a real load.

On my machine, there is a heavy feed wire off the Vector drive which carries the main power to the servo amps, which are all daisy chained together. Check the voltage there, it should be something in the range of 185v DC if I recall correctly.

Because of the symptom which you reported, there may be an issue with your vector drive, so carefully check the various outputs and see if it is producing voltages for the spindle and the DC bus.

If you've got that voltage, then the other voltage to check is on the small yellow/white/black twisted coming off the small power supply, going to the servo amps and also is daisy chained, if you can find it. Check those for voltages in the order of 12v, IIRC. Just looking for signs of life in the right places.

What I was looking at in my VF3 may be somewhat different than what you have on yours.

[BMackinnon]

Thanks Geoff I will try that first thing Monday morning before the electrian comes in.
and HuFlungDung I will leave and pass all that info to the electrician ... I can wire a car stereo but I dont want my mill to play music so I'll leave that to him and someone more liable.

On a side note have you ever heard of anyone regrinding thier own spindle ? I was away from the machine and the bosses brother (who dosent even work for the co.) took it upon himself to run the machine and loaded the wrong stock causing a bad crash which resulted in the spinlde being gouged pretty bad. End result I thought I would try my own thing that I thought of awhile ago. I took a die grinder (yes a die grinder ) and mounted it in the vice, dialed it up and programmed the head to run on its own taper. After a lot of working in and a lot of bearing blue ink on the tool holders I was able to gain full coverage on the holder and save the co. approx. $5000.00. There have been a few reps and other guys from other shops come in (we also do custom tooling) and they said they never heard anything like that before. This was about 4 months ago and I noticed I gained a lot of rigidty also from this. I would say about 8% from what I used to run things. When all was done I just had to adjust the toolchanger hieght a little bit and then she ran as smooth as a babys bottom.
Just wondering if you ever heard of using this method.

[Geof]

Originally Posted by BMackinnon .....On a side note have you ever heard of anyone regrinding thier own spindle......

I have a healthy heart and get lots exercise so I didn't keel over when I read this "suggestion"; you may be responsible for a few conniptions though.

I am impressed; did you do this with your Boss' blessing or present it to him as a success when it was done? Although if I was him I would probably have been too occupied slowly strangling the brother to take any notice of what you were doing .

[gar]

060617-2044 EST USA

BMackinnon:

For in place spindle grinding check out Walt Jr, and Walt III at
Spindle Grinding Service ( www.spindlegrinding.com ).
They are experts at this.

Also see
http://www.cnczone.com/forums/showthread.php?t=21509

.

[Lesleh]

Check to make sure you did not trip a breaker inside the control cabinet, I don't have a VF-0 but on the VF-2 there are 3-4 breakers located above the spindle drive on the power supply card, Be sure to check the one marked solenoid

Hey its worth a try, this happen to me believe it or not when the light inside the machine shorted out