Quote Originally Posted by curious aardvark View Post
looks like a slight wobble.
looking at the machine - no belts all screws - I'd have to say it's a function of the screwthreads and at least one of the threaded rods isn't exactly straight, or perfectly lined up.

Screw drives are all well and good, but don't have any of the built in give or tolearance, that a belt driven system has.

Either that or the threads are out of sync with at least one of the stepper motors.
that said - it's a cool pattern :-)
But I'd bet on it being something to do with the threaded rods.
Thanks for the input. I wouldn't be surprised if my threaded rod isn't straight because, as you may have noticed, the Two Up only has one rod and so the gantry sags on the opposite side and puts a lot of weight on it and could easily have caused it to bend. Does that mean my best bet is to just buy a new threaded rod or is there something I can do to counter the fact that it's not straight?
If this isn't the case however and the problem is that the threads are out of sync with the stepper motors, what would I do to fix this? Is that something to adjust in the settings or firmware or would I want to reseat the rod in the coupler? Not really sure what you mean by this or what I could do to investigate and possibly fix. Thanks