Circles not Round on Arduino UNO R3 controlled CNC

Hello, i was struggling with my machine not cutting round circles but instead they were oval. My solution was to adjust the bearing and nut where the LEAD SCREW rest on the outer plates. There was about 3-5 mm of play. I am posting the video which is in spanish, i am working on a much cleaner version in English
Thank you

It's a bit difficult to offer a suggestion when you have not told us what software is running on the Arduino.

Presumably the relationship between distance and motor-steps is not correct for one of the motors.

...R

The usual suspects are:

  • misconfigured steps/mm for the axis
  • mechanical play (you've already found one source of it)
  • backlash
  • misalignement of the axis (not perpendicular)
  • motionplanner tolerances are set too big

If you are going to make real cnc stuff, then get a decent cnc controller (e.g. linuxcnc)

epnicass:
Hello, i was struggling with my machine not cutting round circles but instead they were oval. My solution was to adjust the bearing and nut where the LEAD SCREW rest on the outer plates. There was about 3-5 mm of play.

Yes, that's not good. There should be zero end-play if at all possible, which means using a preloaded
magneto bearings or similar, where there is already compression between two bearing races to eliminate
any slack completely. For leadscrew systems its normal to use such a zero-end-play bearing at one end of
the leadscrew only (to permit thermal expansion of the leadscrew without jamming).

Any single standard deep-groove ball bearing has endplay.

Another technique is to use a thrust bearing and a spring to keep it under compression. So long as the forces
don't overcome the spring, again no end-play. However you still need an ordinary bearing as well to keep the
leadscrew centred.