The Z Axis motors´shafts lose sincronization slowly, failing the print
My Z axis motor shafts start to loose sincronization after a while. I found in a couple of printing attempts that the extruder was draging through the part while printing ruining the part. I realized the Z axis was completly disbalanced.
I recalibrate the Z few times but the prints keep failing because of the desincronization. On the pictures below you can see a couple of pictures of the failed prints and measuremnts of the Z axis shafts axis at the same time.
¿Do you ever experienced anything like this? ¿Any advices?
RE: The Z Axis motors´shafts lose sincronization slowly, failing the print
i suspect one of your Z nuts is binding or the dust covers are too tight at the bottom of the Z leadscrews
RE: The Z Axis motors´shafts lose sincronization slowly, failing the print
I would also:
Loosen the Z nut screws, both sides. Run the Z axis up and down. Tighten the screws. This lets them align themselves a bit - and is easy.
RE: The Z Axis motors´shafts lose sincronization slowly, failing the print
Substantially loosen the dust covers ... leave them at least 1 mm above the motor.
RE: The Z Axis motors´shafts lose sincronization slowly, failing the print
I tried moving the dust covers up and loosen the Z Nut Screw as you said but it keeps happening. Is like if one side is slowly losing steps and after a while they sum up.
When I print very small parts you dont almost realice that happens but when the print is finished you can easyly see that the X axis is not horizontal because the Z leadscrews are not sincroniced.
Any other advice??
Thanks a lot in advanced. 🙂
RE: The Z Axis motors´shafts lose sincronization slowly, failing the print
Big flat surfaces warp. This happens with all materials. When a part warps, it will lift off the bed or even bend the steel sheet upwards. This has the same effect as if the X-axis is "losing sync" ... and bed adhesion issues are common.
The Z motors losing sync is highly unlikely. The amount of drag would be high enough moving the axis manually would accumulate so many stalls you'd be able to see and hear the differences as the axis moves. The most common cause of these stalls is the dust nut being too close to the motor - which is what your photos are showing. The second most common cause is the T-nut was damaged during install - very common when a person installs and screws the T-nut to the X-frame before inserting the lead screw. T-nuts should be installed on to the lead screw by hand then attached to the X-axis parts.
A fair test would be to turn on the printer, do an Auto Home; then manually (via settings/move-axis) move the Z axis up to 200 mm then back down to 1 mm a few times and measure both side heights each run. Before you start, add a small white dot to each dust cap to help identify any variation or stalls, too. The dots should always be in sync -- if after a few runs they aren't, then check the dust caps again for being too close to the motors.
RE: The Z Axis motors´shafts lose sincronization slowly, failing the print
Hi All again!
The story is long but the problem is solved now:
I folowed all your advices but the prints kept failing....Therefore I kept looking for the root problem... I checked the bearings and founf out one of them was a bit worn, and you could not move it properly.However it was not the real problem ...the real problem came from the lead screw motor! it was damaged but it was hard to see it at the begining. It suddenly started to get blocked while doing Z calibration(see video).After disassembling the lead screw motor it was then easy to feel that it was much harder to move the lead screw manually. I dissasmbled the motor and its rotor was clearly damaged because of friction
- I contacted Prusa and because it was under warrantly they sent me a new motor.The problem is solved now and I am happy out again! the prusa service worked perfectly
RE: The Z Axis motors´shafts lose sincronization slowly, failing the print
Video of the failed Z calibration where the axis fails and Z lead screw missalignment can be seen:
https://drive.google.com/file/d/1BwHyA3kwEpcyyEj4mL17wmJSVHE1P2La/view?usp=drivesdk