X axis experiencing "chatter" "binding" loses position

[prolitesigns]

Recently, our shopbot has started to lose its position in the x axis because of the motors binding. It has only been happening along the x axis. It happens whether we drive it manually, orsometimes it does it while running an .sbp file as well.

I have talked to some techs at shopbot, and I was told that the computer might be trying to access something. Like a program update or something. To the best of my knowledge this is not the case. The computer is standalone, and is not hooked up to internet or any network of any kind.

Also i checked the running processes, and was told to look for some certain programs by a shopbot tech, but i found none of the items he mentioned.

Another thing I was told to try was looking for any cables that had holes or were cut in any places. The usb to serial cable did have a cut in it, and the cable has been replaced with a new one. The problem still exists.

Also, the pending gears were checked, and they are all snug.

Mainly, the chatter or binding on the x axis happens in the same place, usually at either end of the table. Sometimes though, it is a bit more random and will happen in a different location.

Any suggestions would be most welcome.

Thanks,

Tyler
ProLite Signs

[srwtlc]

Tyler, did you drop the motors away from the racks and see how freely (or not) the carriage moves from end to end?

[prolitesigns]

I was informed by Frank at shopbot that since our router was purchased this year it wont have the drop springs.

Which is indeed the case. Both motors were removed though, and run back and forth many times, and they run freely.

So the motors were off of the racks, and they were running just dandy.

So are you saying push the actual carriage back and forth and see if there is anything hindering that?

[cnc_works]

Have you checked the pinions for wear?

Donn

[prolitesigns]

The pinions are fine, the machine is only about six months maybe a little more, old.

We pulled the pinions apart to look at them, and make sure they were tight, and sure enough, no problems there.

The track on the table seems fine too, and is all greased up.

[GlenP]

It may be way off the mark but when I first started up my PRS standard the software was set for an alpha. I had the x motors and pinions chattering in different locations just doing air tests. I checked the software and it was set wrong. Changed to the proper PRS standard and never heard of it since. Just a thought! Good Luck

[Brady Watson]

Tyler,
How can you be sure that the pinions are not worn? If you have been running the machine on a daily basis, it may be just about time to replace the pinions. They sure don't last forever and greatly influence cut quality. Incorrect pinion or motor alignment (is the motor perfectly square to the gear rack?) will cause premature wear. Keep in mind that just because the pinions still have teeth on them, doesn't mean they are still good. The edges wear down and cutting gets notchy and sloppy.

You will also want to check your gantry to make sure that it is square. Do a search of this board, as the procedure has been discussed many times.

-B

[prolitesigns]

Well i guess in that case, I cant be completely positive that the pinions are not worn out. I imagine that they are not too expensive, and its something easy we could try.

Also, im not positive that the gantry and the motor are perfectly square, as I myself have not done that, but the other main operator may have.

Thanks for the tips!!

[harryball]

The pinion on my Y axis looked perfect... I was sure it could not be the problem and I made comments about Brady under my breath as I installed a new pinion (darn Brady, I'll show him...) The replacement fixed the problem so I still had to talk about Brady under my breath. :-)

I'm not sure it will solve your problem, but it is a good starting point.

Robert

[Brady Watson]

Why are my ears burning!!!??? ;)

[prolitesigns]

Well that sounds like good advice. It doesnt seem like it would be a pinion, because the machine is less than a year old, and we dont even use it every day. But im not counting anything out at this point, and your suggestions will be duly noted.


thanks!