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GSM1 occasional fault

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GSM1 occasional fault | 26 January, 2010

Our GSM1 with Flex2 heads started to generate occasional error message:

"Axis head 1 theta positive lead error during move absolute command" and then stop.

After palm-down it runs again for some time. Everything looks fine, so I have no idea where to start from...?

- Deni

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GSM1 occasional fault | 26 January, 2010

Check your belt tension on the theta motor.

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GSM1 occasional fault | 26 January, 2010

In addition to what Jeff wrote (I agree 100%) I would advise installing new theta drive belts on both heads. We had the same error at one time; if I remember right, I was told the new belts are better mat'l. It's likely your old ones are worn.

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GSM1 occasional fault | 3 February, 2010

Hi, First: 1. What os/system? 2. what s/w version? 3. what type of machine model? 4. What type of head configuration? 5. Do you have this head front or back? 6. Do you have encounter this problem before? 7. Have you recently placed any new "high components" or anything new on a new pcb? 8. When the machine stops, before You press E-stop; How is the machine stop? Is there any spindle down to the board and if so which? 9. If not, exactly what is the status of the machine?

GSM1 Flex 2? Flex head 2 is that the 4-spindle 450 gr. placement head, or is it the 4- spindle 2500 gr. placement head?

How was this problem started; while running, or under zeroing or what?

This is essential! If we can, we will try to help you, pls. provide us with this info. Try to be as specific as possible, and perhaps we have an solution for you.

From UIC trouble support below:

If your machine experiences theta errors that include "Theta Velocity Over Speed Error During Move Absolute Command" and/or "Axis Head # Theta Error Not Recognized During Move Absolute Command", you may have an issue with the theta axis bearings. To verify this, palm down the machine, rotate the theta axis by hand to feel if the axis is rotating freely without binding. If you feel binding, remove the belt between the theta motor and the T-bar and rotate the motor side and then the spindle side to isolate where the binding is. The T-bar may also be removed to isolate each spindle. The bearings for binding spindles may need replacing. See drawing theta bearing replacement. Check other head if applicable. This bearing issue only effects Flex (FX) and C4 (HF) Heads. There is no need to proactively replace any bearings.

Best Regards,

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GSM1 occasional fault | 4 February, 2010

OK, here we are: 1. OS is OS&2 2. Sw. is USOS V1.14 3. GSM1 4. 2 Flex2 heads 5. Problem is on the front head 6. No 7. No

8. It just stops in the middle of the placement phase, with the head over PCB area. Usually 2 parts are still held on the nozzles.

9. Machine prints ""Axis head 1 theta positive lead error during move absolute command" in the status window and halts. If I press e-stop, it generates repair program and I can then continue.

10. It always occurs during placement. It started one day and we had 6-7 failures during morning.

11. UIC's troubleshooting site says nothing about that particular problem. I've checked everything that can be related to the theta axis. Belt is OK, tension same as on the second head (I've also compared it to the spare head we have), everything rotates smoothly, I've checked connectors. And then, as I run of the ideas I've posted a question here. I finally "solved" it by rising error threshold parameter in the axis setup from 25 to 35 and it never repeated afterwards. Since I actually didn't fix anything I would like to know where the real reason for such behaviour might be.

- Deni

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GSM1 occasional fault | 4 February, 2010

Hi, I know that I been out for this exact error message before (several years ago) and I am just thinking about it. It was something simple...

Ok. When You say stops in the middle of placement phase; Do you mean in the first task block, have it already been doing some placements before or does it stops directly after the machine has just read the fiducials and then it's prepared to go to the placement position and stops? Ps. Sorry for my poor english & grammar. Do You know Swedish? Ds.

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GSM1 occasional fault | 4 February, 2010

You don't by any chance have a s/w called Motion Control s/w? it's on 1-2 floppy diskettes and it will boot from it also. Normally only the UIC field engineers have/has? this.

With this we can actually run each axis & valve or whatever independently, from each other; one at a time. Much easier to pin-point the problem area.

My English it's not so good. Sorry. /Mika

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GSM1 occasional fault | 4 February, 2010

Hi again, Now I think I know the problem. Everything doesn't rotates so smoothly as you may think. It could feels like that when you manually rotates it, it's a complete different business while running!

First: How did you check the belt? With a naked eye? Even with a magnifier it's hard to very hard to see if some of the teeth are just a little bit out of order.

But my money is on the motor itself; we have had the same problem and even if you think that the motor feels OK,it could certainly be bad.

But start with to check the belt sprocket on top of the motor shaft; it's a very small allen screw that's tighten this to the motor shaft. It's known to going bad, especially if the belt or the motor is bad. If this is not tighten and firm to the shaft => Problem!

Then replace the motor! Why not replace be belt anyhow? How long was it since the last time you replaced any belt?

Another thing you could also do; In the LP (Low Power) chassis lower front left, find the correct motor servo card and "Null-it-out" 2 small pot's and the procedure is in the manual. But then again, perhaps you need the Motion control diskettes, I don't remember. It was maybe 4-5 years ago since I had my hand into the GSM:s

Sincerely, Ps. Keep us posted. Sorry for my poor English. Ds.

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GSM1 occasional fault | 4 February, 2010

Put new belts on. Tension means nothing if belts are worn out and stretched.

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GSM1 occasional fault | 4 February, 2010

Right! I agree 100% /

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