Universal Laser issues with X-axis skipping

I have been having problems with the x-axis skipping randomly, on multiple jobs, with laser engraving (though so far not on cutting). It is not in the same spot each time and does not "jump" the same distance--one time it may shift a quarter inch and the next it's an inch and half. However, I do hear a "click" right before the shift.

We have a ULS 6.60 laser that is four years old. The x-axis pm was performed in February this year (new belt, bearings, idler, and drive gear motor).

We have taken the x-axis apart and cleaned and inspected the belt and all other parts, and double-checked belt tension with a spring scale.

I have called Universal Support several times, but haven't got any other suggestions. I have jobs backed up for the holiday rush and am starting to panic!

Any suggestions would be helpful. Thank you in advance!

Sandi Marlowe
Spark Laser Creations
Livingston, MT

Have you cleaned the encoder strip? Not sure where it is on a Universal, maybe someone with one will chime in.

Not one to clean Gary. Different animal.

Maybe a motor encoder going bad? Just guessing.

Quote:

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Originally Posted by Scott Shepherd

Not one to clean Gary. Different animal.

Maybe a motor encoder going bad? Just guessing.

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Does it have one like my old GCC, on the end shaft of the stepper? It was just a disc enclosed inside a housing, it got fairly dirty with the right (or wrong...) material being lasered.

Quote:

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Originally Posted by Scott Shepherd

Not one to clean Gary. Different animal.

Maybe a motor encoder going bad? Just guessing.

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What is a motor encoder? Haven't even heard of that before! Many thanks!

The motor, internally, has a mechanism that keeps track of how far it's supposed to move. At this point, it's one of the few things left to try, a new X-Axis motor. I suspect ULS will be heading to that soon if they can't resolve it any other way. There are motors and boards that drive those motors. One of them is going bad, I'm guessing.

Yeeks. Doesn't sound good, but I'd rather know what's going on and get it going again.

Thanks for your help.

Loose set screw or other on pulleys, bad spot on belt, loose connections even a plug in connection. Try unplugging and re connecting plug connectors.

We checked set screws and belt, but didn't think of the plug connectors. I'll try that too. Thanks!!

I know it might not be the issue, but a few years ago our PLS 360 was doing this. After days and days of customer support and them sending us entire new arms and encoder strips we figured out the problem. It was our COMPUTER! The RAM was going bad and somehow that was causing a hiccup with the engraving software and caused the x axis to do things like this.

That's a good point. Years ago when I had a ULS, I ran into communication issues between the pc and laser. Usually it was the cable.