I wanted to cut some circles in plywood for one of my projects but I can get a good cut, it happens to be the first cut I made on my Workbee, I was stumped as to why these circles weren't concentric. I made sure my feeds and speeds were correct with the Alex Chambers Feeds and Speeds chart and it can't be a rigidity issue cause my machine is sitting on a concrete floor and has all of its concentric wheels tightened. I also calibrated all axis through OpenBuilds Control so that couldn't be it. I must be missing something but not too sure. It could be an issue with the stepper motors but I'm not sure. I'd love some suggestions to try. Here's the kind of cuts i get
Belt drive Workbee? Check (and add locktite between shaft and pulley, as well as the grubscrews) and tighten the pulleys grub screws. Check belt tension (pull to 10-12kg) Leadscrew driven? Check leadnuts mounted properly to plates Check shaft coupler just like pulleys above, can slip on motor shaft or leadscrew side if loose. Loctite again helps (vibrations loosen screws) Something is loose. A.k.a backlash
As @Peter Van Der Walt said. It is also possible to over-tighten things causing some binding. Check first for something loose as that's the most likely, but also check that you have the eccentrics properly adjusted - you should just be able to turn a V-wheel with your finger and check that you haven't overtightened the nut blocks against the gantry plates. Alex.
