Out of square at initializing and in the middle of jobs

The past few days, my 5 Pro 4x4 has started somehow becoming out of square. This came out of nowhere and after running jobs for well over a year. It first occurred Tuesday and Wednesday when trying to initialize the machine. I finally got it initialized and then it happened in the middle of two jobs, back to back, throwing the whole machine off and basically ruining two 24x48x3 wavy flags. I have contacted support but they are refusing to schedule a call or video chat, which has never been an issue previously, but is getting extremely frustrating. Does anyone have any ideas?

I would start by checking all the fasteners and see if any have worked lose. If they are lose or not you should start the steps to square the machine again.


I triple checked everything at this point and everything is tight. I wish I could upload video. The sound is god awful.

Anything preventing one of the Y axes from getting to the hard stop?

I’ve checked all axis points and screw drives to ensure they’re clean and unobstructed. That was my initial thought as well.

Make sure that you have enough lubrication in the bearings so they are not binding on you.

As suggested previously, oil you machine first. You will probably find resistance in a bearing because dust from all your awesome projects has found it’s way in there to sabotage you. It’s much easier to flood a bearing with oil to force out contaminants than it is to disassemble it and pick out debris, unless you like monotonous work with magnets, picks, forcepts, and many little ballbearings. If you’re interested in actually finding the problem, continue with my nonsense… As a technician, everyone has different troubleshooting techniques. The one I’ve found particularly helpful on the shapeoko is verify everything individually, since everything is conservatively designed making them all weak-links. You have already checked for tight fasteners, good. I’m assuming this means you’ve already checked the couplers’ set screws. The motors are screaming at you meaning they are trying, so the controller works. Now check motion.
Remove the steppers for your Y axis. Steppers rarely go bad, but you can check them for wear by disconnecting the harness plug (backfeed prevention), then wiggling the shaft side to side for runout and in/out for backlash/overtravel. Both will likely have minescule slop, but they aren’t direct-drive, so doesn’t matter much. Then spin them to test bearings. They have magnetic resistance, so you should feel a bunch of tiny clicks(steps). Both should feel the same, so move on.
Slide your gantry front to back without the steppers mounted. Grab left and right sides and gently pull the gantry allthe way forward. Then gently push it all the way back. Pay attention to whether one side is tougher to move, maybe even just in one spot if travel. If a problem area is found, diagnose the route cause. Misalignment is possible but unlikely on the 5’s y-axis, since each side only has a single rail with 2 linear bearings.
You can narrow down which bearing by proceeding to check them individually. I would suggest using a block of wood propped under your gantry if you’re worried about OSHA. Remove the 4 mounting bolts to the front linear bearing and slide it forward and back. Easy? Good. Align your mounting holes, finger-tighten all 4 screws and tighten them in x pattern (blue loctite 243 is your friend). Now the back bearing, same process. If both are good check the ballnut. Move the gantry to the middle of the machine. Remove the bolts to ballnut mount and slide the gantry back to expose just the ballnut. Grab the aluminum block and slide it back and forth a little. Won’t need to slide it too far to know if it’s a problem. The ballscrew should turn almost effortlessly. If resistance is met, determine if it’s the ballnut or the end bearings at the drive side (5pro only uses bearings on the drive end of the screw).
If the linear bearing is the issue, oil it from the grub screw. If the ballnut is the issue, use your judgement. There is a port on one side of the ballnut flange, not sure if there’s a grubscrew inside, or if they just packed it with silicone/ptfe grease. Any problem bearing should be flushed with oil. wd40 could work for flushing to save some vactra, but you’d still have to re-oil with vactra afterwards. So clean and oil and work the bearing until it’s all smooth. Now you can be confident you’ve done your best to resolve the problem, and practice more vigilance at cleaning and oiling. Never use compressed air! This forces dust into places it shouldn’t be. Little soft brushes and cloth rags with oil…
Wow- I didn’t expect to have that much to say.

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