Z axis loosing steps ***SOLVED***

I started a topic about a problem during leveling but the real problem was that the Z axis is loosing steps as addressed by nopick.
https://forum.lulzbot.com/t/autoleveling-does-not-level-the-print-bed/2003/1

To keep some order in the forum I have started this new topic with the real problem Title.
Here is a example of the results that I am having… as you can see the problem is not always present at the same Z but some kind of random…




Piercet, The printer is lubed and aligned, the screws of the z axis couplers are OK

I got a couple of good prints at the beginning so I do not think that the motors are not aligned…and the connectors seems to be OK.

Could it be something related with the firmware?

If its happening mid print that’s either a couple slipping issue or an electrical short in the z motor cable. Definitely not firmware. The z steps value never changes mid print.

Electrical spikes or brown outs? Maybe a UPS that handles brown outs (not all do) would help. If it does, you’d have the added bonus of being immune to small power outages.

If the axis is binding or the motor has issues it will miss steps. If it was a power issue he would have problems on all the axis’s.

I noticed that the fan of the power unit was having a bad contact (probably the printer was dropped inside the case during the overseas shipping). The fan was stopping sometimes during printing proces allowing the board to heat up too much…
I connected it again firmly and the first print after that is being nice and smooth… :smiley:
Does it makes sense for you?

If the fans operation or lack of operation in the Control Box allows the motor drivers to get too hot it will drop/skip steps. Or at least it does on my Taz. :sunglasses: