circle turned in to ovel

[karandex]

I have made a mantis like machine,
first i want to clear problems i have

1 the x axis motor is not screwed tightly, if i tight them due to my machines wrong construction lead screw stalls.
2the nut on x axis is placed with epoxy and a metal strip.(just like in vid)
but now the nut wobbles in y axis

the picture is of circles for test
outer is 40mm dia and progessivly 2mm decrease

Help me to find which one of the thing is causing problem.

PS i want to use drawer sliding for my next cnc, (just 2x mantis) whats your say when comparing to rods ?

[karandex]

please help me guys

[gmfoster]

please help me guys

Well you need to isolate your moves and figure out why you are going father in one direction than the other. The lines are meeting somewhat closely so it seems that more is wrong than just missing steps.

I would write gcode to draw a ruler and then run it going from left to right and then from right to left..

This 'could" be something as simple as the step pulse duration.

If you move a distance left then back the same distance right do you go the same distance..

And the first thing you need to do is find why you have loosen the motor, that means there is binding somewhere and no one can help you with that..
Garry