Problem- Continuing 4th axis and electrical gremlin woes

[ralph@nes]

Please refer to my old, original thread:

http://www.cnczone.com/forums/showthread.php?t=45025

Since then, I've had the 4th axis working normally most of the time.

Notice I say 'most of the time'. I would spuriously get odd errors on it; Following errors, a motor faults, z faults, etc. Then it would work fine for a week, then have fits.

Along with these crazy and sporadic problems, there's other electrical gremlins; The machine will change spindle speeds by itself, will come off feed hold by itself, and rapid and feeds will decrease without the buttons being touched. I've replaced the keypad to try to take care of that, to no avail. This thing just plain acts weird.

You'll be ten feet away from it and hear 'beep' and the rapid has dropped 10% or the spindle has dropped 10%. Doesn't seem to be temperature or vibration related and I can't find one common thread as to what might be causing these sporadic problems.

The thing that is frankly angering me at this point is that it won't just break and stay broken; I can't troubleshoot it because it will start working normally again. This past run, the axis errors are semi-permanent; I've had the axis off the machine and back on and it's still not working correctly.

I'm at a loss here. Any input is appreciated. Even the techs at the HFO can't seem to give me any advice. I'm at my wits end.

[Al_The_Man]

Does this have discrete buttons for the operator panel?
If so, a bad connection somewhere will cause a disruption of the (24vdc) supply to that section, this will have the effect of changing switch functions, just a thought?
Al.

[ralph@nes]

You mean the buttons that have some 'push' to them? It's still a membrane type pad, but yes, it's not the original 'flat' one.

[awesome83]

If the machine is new enough, I don't know the cut off, but if you get into debug mode you can see the history of keystrokes. This may help see if it really is a key "being" pushed.

The way to get to debug and see the key history.

Setting 7 off
Press the alarm button once
type DEBUG (should see N's on left side of screen, AKA NNNNNNNNN
press the current command button
press page up untill you see the key history page.

I have personally seen the buzzer/beeper short out and cause several issues. Controls to lock, short out the SKBIF (serial key board interface-the small board that the keypad plugs into)

I would unplug the beeper and see if that helps, also you check all the grounds in the pendant area.

Next i would try a new SKBIF.(sounds like it me) Feed hold also goes through this board.



hopefully this helps some.

[1ctoolfool]

depending on the age of the machine, there can be a bad ground. static discharge can lock up the machine, but I never heard of the gremlins you describe.
ask your service tech about the bad ground handwheel, seems to be worse on machines with remote jog pendant

[ralph@nes]

Thanks for the input, guys.

The tech did mention a ground issue could be at fault. This is a 1994 machine with no pendant, btw.

I believe that since you hear a 'beep' when the changes are happening, it will probably show a button push, which I probably will have to chalk up to that SKBIF board.

How would any of this have any effect on my A-axis woes, if anything?

Am I really at the point where calling a tech is the smartest move?

[Bryan33]

I am a service Tech with the Haas factory and I would be happy to help you out with this problem. You email me your info at bwilliams@haascnc.com and i will call you back to help you with your problem.

[ralph@nes]

Originally Posted by Bryan33 I am a service Tech with the Haas factory and I would be happy to help you out with this problem. You email me your info at bwilliams@haascnc.com and i will call you back to help you with your problem.

Thanks, Bryan. I've emailed you.

[ralph@nes]

Well, here's results of some testing.

1. Ohmed out my cable and my wiring in my Rotary table internal wiring harness all the way to the encoder. All wires have continuity and there are no shorts.

2. Swapped my A motif with my Z motif and ran the Z axis on the A motif with no issues at all. I think it's safe to assume there's nothing wrong in the machine itself causing my A axis to malfunction.

If I've ruled out the A motif, cable, and axis internal wiring issues as being good, what is left? Encoder?

The primary error I am getting now is A motor over current. I don't know where this is measured, so I'm not sure where to start looking. The motor itself, and brushes, are spotless so I have a hard time believing it's a real motor failure.

Where else can generate that over current error?

Thanks again folks.

[Al_The_Man]

I would disconnect the motor mechanically from the machine and try running it free and see if it goes into OC.
If it is OK then I would look for something mechanical on the A axis.
Al.

[ralph@nes]

THanks Al. I have a whole new problem now that's a bit more immedate than the one I'm discussing here. Starting new thread, appreciate any input from anyone asap.

Failed display thread here ====> Continuing 4th axis and electrical gremlin woes

HELP!

[Al_The_Man]

That loops back to post #1, do you mean you have the same problem again as this post?
http://www.cnczone.com/forums/showthread.php?t=45025
Al.