It’s not so much the set screws, lots of other machines use these successfully, it’s the lack of threadlock on those set screws allowing them to vibrate loose. There’s no shortage of holding force when they’re done up properly.
Using larger head steel bolts in these small thread aluminium pulleys to get more torque on the screw would likely move the problem to people stripping the threads out of the aluminium pulleys.
Sent this to support@carbide3d.com and sales@cardbide3d.com. Hopefully it will get some traction and a resolution.
Hey Carbide3D team,
I’ve emailed about this long ago and continue to see this problem in the forums. The set screws used on the pulleys are inadequate and often slip, especially for new users. I documented a simple fix here:
Pulley set screws - XXLThis is a solve that would cost Carbide3D near zero and prevent frustrating new user experiences. In the forums they get misdirection about material forces, speeds and feeds, and slotting. The short story: it’s a design flaw that Carbide3D could resolve.
Shapeoko XXL - final pass is stretched or offset
Shifting off trackLooking through the posts and replies, dozens of people have had this problem. How can I help you champion a change to this simple issue that causes a lot of grief and ruined projects, especially for your newest users?
It would be amazing if they proactively sent every owner a pack of 8 M3x8MM cap head screws and small tube of removable thread locker. That would be Customer Obsession! 
So, as an update. I have been trying to tighten the x-axis belt. Unfortunately, I feel I am getting the belt as tight as possible, but it is not solving the issue. My speeds/feeds are slowed way down as well. I am lost for answers and getting frustrated! Is there another way to tighten the belt other than wrapping it through the little bracket and tightening the set screw?
Please post a file which causes this problem, or send it in to support@carbide3d.com — include the generated G-Code and step-by-step notes on how you are securing your stock and setting zero to it and managing all tool changes and we will do our best to look into this with you.
The screws that attach the tensioning bracket to the end plates are not set screws. A set screw does not typically have a head. See below:
One set screw should tighten down on the flat of the motor shaft.
Thank you so much for the explanation. I definitely have been looking at the wrong location to tighten the belt.
Question: Is there a proper way to access this piece? I can probably take things apart until I reach it, however this is definitely not the desired approach.
Thanks again, and all help is very appreciated!
@WillAdams or someone with a Pro will have to chime in here. I have a Shapeoko 3 so I don’t know exactly how the Pro is built. I imagine there is an angle at which you can access the set screws without disassembling it. You may have to anyway in order to verify that one of the screws is on the flat side of the shaft.
Because of the shroud for the X-axis it will be necessary to slacken or possibly remove the belts and then remove the X-axis motor.
This topic was automatically closed 30 days after the last reply. New replies are no longer allowed.
