Thanks Robert, I will run the gamut on things that can loosen and things that can tighten again to see if there is a hidden culprit out there.
Thanks for your quick responses 
Pulley set screws are often the culprit with odd errors like this…make sure they are all tight.
I am in the middle of the process of improving my ShapeOko2, one thing I noticed was the flat spot tyre you get when you over tighten the wheels. So maybe loosen up the wheels. Now I put them just tight enough that I can barely turn the upper wheels by hand.
Have you tried the example I sent earlier?
Okay… went back to basics almost taking the thing apart! Took your advice (Robert) and assumed I should quadruple check everything again. Wheels were all tight… maybe too tight? So loosened them and tried again…
95% success… the issues were nearly all resolved. Still have some slight wobble so assuming that the wheels are now either too loose or the two wheels on the left Y rail that I didn’t loosen should be relaxed a bit.
Erik, yes, thanks I did try the example and it didn’t change the end result unfortunately but in a way that was good as it meant that it was not software (as most suspected).
So… over the weekend, I will finish the wheel adjustments and see what that does. I was going tighter when I should have been going looser…
Thank you all for the advice.
1 Like
One of the things I noticed when setting the wheel tension is that it makes a huge difference if the rails are not perfectly aligned. On the X gantry I loosen the wheels and put a finger on every top wheel, then move pushing it down I feel if they all run at the same friction. If two wheels in cross opposite position have more friction than the other two one of the rails is too low on one side to be parallel. When tightning the wheels if tightening one wheel has an effect on another wheel there is a misalignment too. So my bolts for attaching the X-gantry makerslides together are tightened AFTER wheel adjustment. After setting the Y wheels I loosen and fasten again one side of the X makerslides to take out any warp tension that might have been introduced by setting the Y gantry wheels.
A properly aligned machine allows smooth hand movement on all axes, when forced it will feel heavy and even bumps that feel like a flat spot.
Hopefully your machine will run smooth after the week-end