Hey guys, how’s it goin?
Wanted to see if anyone could tell me what they think caused this. I started my Shapeoko 3 XXL today after probably about 3 months just sitting there. Started up fine, initialized fine, so I went into CC and whipped up a small little project. The machined needed to simply cut about a 6" circle on the right and then go cut the same on the left. It successfully cut the one on the right so good, I’m just at a lost as to what could have caused it to get off track on the left circle like this… : / my board did not move, but the only thing that does look a bit different since the last time I successfully used it, is the belt on the x axis seems a bit more floppier than used too. That is “all” I seen and again, I have no idea why it went off it’s route like this, you?
Sounds like the “X” and/or “Y” axis belts are loose and need to be adjusted. Looks like it might have skipped a tooth due to the force of the bit moving through the wood.
Here is a link to some belt tightening recommendations posted by Will.
ok, thanks, I will look into this. May needta just purchase an belt kit
Check those drive pulley grub screws while you’re there.
To add to what @Ed.E said there are two set screws on each pulley. One of the set screws should be on the flat of the stepper motor. When you have one set screw on the flat and the other one tightened use a permanent marker to put a line across the pulley and shaft center. That will always give you a quick visual check to see if your pulley is properly aligned. If you see that the line is not lined up with each other you know the pulley has slipped.
After checking the belts and the pulleys make sure there were no obstructions like clamps, vacuum hoses etc in the way.
Also check your v-wheels. To check them lift up on each end of the gantry. There should be no play. If it lifts up you adjust your bottom v-wheels by inserting an allen wrench and slightly loosen it. Then use a wrench to adjust the eccentric until the wheel is snug and not deformed. Hold the wrench in place and tighten the bolt. If you do not hold the eccentric with the wrench it will change due to the torque of tightening the screw. Do the same for the Z axis. If it is loose the same procedure is used on the bottom two v-wheels. The top v-wheels are just idlers and are not adjustable just the bottom ones.
Thanks everyone who chimed in, but I have to be “completely honest” when I say, I have no “ca loo” what half of these pieces are you are suggesting I look at without pictures. I mean, I have barely used this machine in all the years I have it and am no where near close to having all the nomenclature memorized on it (that’s on me) = drive pulley grub screws? on the flat of the stepper motor? I just…I just gotta keep it real, I don’t know what those are?
Pulley set screws should be covered in:
Ideally, everything would be explained in:
Now “that” really helped. Thanks. I don’t seem to have that issue though. Mine seem to be locked pretty good, not slipping, betls on both the left and right seem to be working correctly on those pulley wheels
When it comes to those pulley grub screws it’s really important to be sure that one of them is tightened down on the flat part of the stepper motor shaft. It’s pretty easy to see that on the Y motors. It’s the X motor pulley that can be difficult to verify.
Put a “witness mark” on the ends of the pulley/motor shaft.
If things are still slipping, then you may want to look at a Maintenance Kit which will allow rebuilding the machine to pretty much like new:
(be sure to pick the right machine type from the drop-down)
The best check is to install a probing pin, jog the machine to the center of motion for each axis, then grab the tip of the pin and try shifting in all directions — investigate any movement.
A further check for the Y-axis:
- power down
- remove both Y-axis belts
- put a bit of tape on the pulleys (so as to more easily see their rotation)
- power up, connect initialize
the machine should home Z-axis as normal, then try to home X- and Y-axes — the X-axis should also home as expected, while the two Y-axis motors should turn until they time out — do they turn evenly and in synch? If not, check the wiring and connectors (they should all be secure and positioned so that wiring leading into and away from connectors does not shift as the machine moves) and see if the controller needs to be replaced.
I looked and double verified, both pulleys have a screw tightened on what appears to be that flat end inside the wheel, so I think those are good. Question, if the belts were slipping on the pulley motor, would the machine still be able to go to all the Rapid Positions using CM? would the machine still be able to cut the circle perfectly on one side than the other side? after all this, I’m starting to wonder if my Beast rough cutting bit was just too aggressive, as I moved another project to the left side of my table, and did a simple V carve on the surface of some wood and that came out perfect…
You can always retest that circle with a different bit running default feeds and speeds. If your good with that test then you have a starting point for the aggressive bit.
yep! that’s where I’m currently at now. Thanks though
So I cut 4 rings out of MDF, the machine still moves like it’s going to do it’s job, even on the left side, but there “has” to be “something” wrong, as the design was the same for all 4 rings and when stacked on top of one another, instead of lining up the look some what like this image:
Does that confirm to those of you that know, that it’s probably my belts or v wheels (which I have purchased and have coming even if it’s not)
For small differences on a machine in good electro-mechanical condition, it’s probably climb vs/ conventional milling and tool deflection — leave a roughing clearance and take a finishing pass.
I have the S5 Pro for reference but I know my tolerances were tighter when using a finishing pass for final dimensional cuts especially in harder material. I don’t want to sound like I was having issues to start with but the finishing cut process allowed me to mill the part down at much higher feeds/speeds for bulk removal and then the final pass was still at high speeds without loosing tolerances due to the very light chip load. Especially on smaller diameters bits 1/8” and less.