I've set up a pick and place system.
After a poweroff (the next day) when I turn the robot on and calibrate it again, the coordinates are not the same as before. All axis are between 5 to 10 mm off.
I've tentioned the belts. I don't feel any play when the robot is powered on (maybe a little play but not much).
And it is with all axis so if one belt was loose you would see a difference in X or Y.
It is not a problem with the encoders because the program works fine when in operation. Only after power off it looses the coordinates and I have to teach all positions again. I have not found a pattern in it yet. So e.g. Z is 10 mm off every time.
Any ideas of what I'm doing wrong?
It is not usable this way.
If it is off by 4mm after powering off and back on I suspect the arm is moving slightly when powered off? as the motors do not have brakes it must remain undisturbed or be recalibrated. I am concerned that previously you said after calibration its off again. I would recommend replacing any damaged switches and adjust the calibration offsets using a digital level or angle gauge to ensure each axis is 0 or 90 degrees when in the home or "L" config and then when you are confident it is calibrated and all axis at 0 in the home position touch up your points and then verify it can repeat after recalibrating. Please keep me posted on this. You can also email me at info@anninrobotics.com as I check my email regularly and can respond more quickly.