Backlash using X belt drive

Messages : 3
Enregistré le : 27 avr. 2018 01:40

Backlash using X belt drive

Message par ViiD »

I've been wondering if i did anything wrong, I'm getting 0.5mm backlash on X axis. Belts are very tight, it seems as if X carriage is twisting....

so if the X axis should be like
--------------| |---------
--------------| |---------
| <--- this is endmill
What actually happens, when I go to the left, carriage is like this:
--------------\ \---------
---------------\ \--------
and when I go to the right, it bends the other way
--------------/ /---------
-------------/ /-----------
I've already tried tightening the linear bearings untill they got too much resistance and were hard to move, but the sweet spot between too tight bearing and too loose bearing is at +-0.5mm error, otherwise it only gets bigger when I tighten the bearings more.
Is there any technique for tightening X carriage - what to tighten first and what to look for?

just to clarify, i'm talking about X carriage:

In case its a common problem, i made a python script to compensate the backlash (for G0-G4 commands), which takes .gcode and compensates the backlash by taking additional moves. I would however like to resolve the problem at its roots.
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Re: Backlash using X belt drive

Message par RoMaker »

Personally I tighten the nuts in ways that the bearings rotate even touching them when I move the carriage.

I only see a deformity when I force with the hands, but it is minimal and does not affect the job.
I still planned to stiffen the x carriage on the future version, with new slides for Z and M8 threaded rods instead of M6.