So I'm seeing a very odd issue. When I cut a circle two "corners" are thinner than the other. It's tricky to describe but the front left and back right are different from the back left and front right. If it was an oval I would say steps per inch is off. If it was staggered between layers I would say losing steps. I've adjusted the v wheels, increased the stepper current, nothing seems to eliminate it. Anyone got any ideas?
As @JustinTime said we really need a pic, but also some information about your machine would help - what machine - belt or leadscrew drive - controller. They might all give us a clue about what to suggest might be the cause. Alex.
I'll try to get a picture, it's 0.03 off, enough to make things not fit right but hard to capture! As for the type of machine, it's a openbuild electronics kit smashed up with a millright carve king (so, trash) that is leadscrew, dual y-axis motors. It uses delrin anti backlash nuts that arent great so maybe that is the issue. The tricky thing to me is that its not X axix, or Y axis, but two of four combinations of directions...just weird is all. I'll try to get a pic!
If it's an consistently an oval but rotated in C by 45 degrees, that is a weird one. Backlash in one axis would typically show up in the quadrants though, so it seems to be that. Could be the backlash nuts, could be the motor/screw couplers. If it's not either of those, that's when it gets interesting. If the screws are skinny and the nuts are super tight, it could be torsion of the screw itself, too- stick-slip behaviour in the nut and the motor twisting the actual screw until it turns. Backlash shows up in all kinds of crazy places.
Yeah one of my main complaints with the design of this machine is the ABL's for the Y axis are unable to be adjusted once the machine is built, so you have to line them up PERFECTLY early in the build. I think I am going to drill a couple small access holes to be able to adjust them in-situ because I have suspected since I built it that it isn't aligned great. I think I also have more work to do with the ABL's in terms of adjustment. It's nearly impossible to tell once the thing is built how much grip they are putting on it, not sure if I have too much or too little... Also good idea about the couplers, I didn't really check them as part of this.
