I stumped ULS Support!

[matt heinzel]

We are running a PLS-360 machine from ULS. The other day I noticed that when the jobs were finishing as the carriage returned home it would actually hit the top of the system on the Y axis. I contacted ULS support and after a bit of tests they said it was most likely the sensor for Y and I would need to replace the board. Strange thing is when the machine starts it properly homes to the top right corner. Well we ordered the part and installed it yesterday, and the problem is still the same. Before I called I did a few more tests and figure out that if the carriage is in the lower left hand corner before it returns then it homes just fine, but if it is on the right hand side of the machine it hits again. I called support and re-explained my issue and also told them about the left vs right symptom. They had me run the same tests and also said the board that was sent was not the issue since it does home on startup. After a long series of questions they were stumped. He said it might be the y controller that is on the CPU, so this morning upon their suggestion I swapped it out for one of our other PLS systems. It actually got worse, not better. Now it was hitting the bottom of the machine when it started engraving and then still hitting the top after it was done. Before I give a call back to them does anyone have an idea on this?

Right now we have the system setup to re-home before it starts new jobs, but I'm not sure how long that will be a "solution" with it hitting often I'm sure the arm will go out of alignment.

[Dan Hintz]

In cases such as that (had at least two separate odd homing issues during my ULS ownership days), my experience has shown it to be a driver (firmware) issue. After filing a complaint (or sometimes not), the issue would disappear after the next firmware update or two.

[matt heinzel]

Dan,
Thanks I will see if updating helps it out. I told them what version I was running and they didn't seem to have issue with the version I was running.

The engraver that uses that system just called up to my office to tell me that our workaround with the re-homing was not working :-(

On a side note I noticed that I can easily "twist" the are to make it go out of alignment any idea what might need to tightened to resolve that issue? Seems to have started after I took the arm off to replace the board yesterday.

[John Volkmar]

I would replace both Y axis Drive Gears, as the set screws are no longer gripping the axle tight enough anymore. After replacing them, I would loosen the three screws that lock down the left side Y axis bearings and move the arm manually all the way front to back several times. Then tighten them back down. This may be contributing to your homing issues.

[matt heinzel]

John
Thanks I will definitely give this a try.

[matt heinzel]

John
All I had to do was tighten down the right hand side clamp on the drive gear screw.

[John Volkmar]

Good deal. Did your homing issue go away?

[matt heinzel]

Yeah the machine is back up and running exactly like it should. It always amazes me that I look for the more complicated solution before looking for the easy fixes!