Backlash on X motor

[Joe Porter]

I have searched the forum looking for information, but not found a definitive question and answer. My Buddy Standard has developed a descernable amount of backlash measured at the pinion shaft. I removed the table and can feel and see definite movement and hear a clicking noise. This is with the control box on or off, no difference. I have run the pinion both ways several times, but it still has backlash. I believe it is about a 1/64th of an inch at the pinion. is this normal? Is there something I need to do to repair or adjust? The driver went bad a year ago and I replaced it. All seems to work ok, but I have noticed that my carvings with .125 ball nose don't seem to be as sharp as when new. The machine is 4 years old. I don't feel any movement in the Y or Z axes. Any help would be greatly appreciated, joe P.S. I went for the grub screws right off and they are tight...

[paul_z]

Joe,

I have a 48x96 PRT Alpha so I can't help you with this issue except to note that shopbot has a (good) habit of putting a set screw on top of a set screw. If there are two, you need to make sure that the one touching the shaft is tight.

I'd also suspect that the pinion gear is worn. Check the Z pinion and the X pinion. Do they look exactly the same in terms of wear? They are other posts that show what worn pinions look like.

Paul Z

[garyc]

Joe...
You may have to crawl underneath and look, but check to see if there is a bind or something that is not allowing the pinion lockout lever to return to the fully engaged position. Using a flashlight (and maybe a friend) work the handle back and forth to make sure the in/out mechanics have unobstructed travel.

[Joe Porter]

Thanks, Paul, I will check that.
Gary, I had the aluminum table totally off the machine and was turning the pinion with my fingers. It looked like the pinion shaft out of the gearbox was moving with the pinion. Does the gecko have anything to do with the backlash? As I said, I replaced the driver a year ago, but did no adjustments, just plugged and played... Thanks for you-all's help, joe

[garyc]

Joe...
If you have eliminated the above check, then you may have to send the motor in to ShopBot to be checked. I would call Tech Support first, in case they have some magic for you.

[Joe Porter]

10-4, thanks. Gary. joe