Z axis nc control

I am ready doing tests with the MPcnc. The crown test file was done several times without any problem. But milling a stl file of a topographical region let the z movements look like out of control. After a normal beginning it dives too deep into the material and afterwards it does some air milling.
The data is given from Estlcam to Repetier Host, to Repetier Server and then to the MPcnc. I searched the forum and followed the hint “long USB cable”. But a short USB cable did not show any improvements. It still dived sometimes too deep into the material, milled in the air and milled through “mountains”. Is there a setting in the dataflow of Estlcam to Repetier Server which may cause this strange tool path behaviour?

Are your z movements double what they should? like that axis might be in 16th stepping instead of 32nd, did you get everything from me or did you do it yourself?

No, they are not double, I got everything from you. On the pics yo may see the differences of height when diving into the material as the cut mountain.

You zaxis might be the trouble. This wasn’t a problem for the last 8 months then all the sudden a lot of issues. So what you are saying is it goes down fine but doesn’t come all the way back up correct? If that is the case below are the most recent solutions found here in the forums.

The last couple were solved byt tking off the anti backlash spring and small nut, or turning up the z axis driver, or making sure your dewalt is not hitting the middle assembly.

thank you, the test I just made was directly from the Repetier host in a contradictionary behaviour. First it moved to much up, milled in the air, and after a manual correction it dived too much into it. I follow your advice tomorrow asap. Call it a day

I took everything apart, checked , compared, and … after reassembling faced the same problem. As advised I took the spring and the 5_16 nut off the Z nut lock - it works. I am happy that the 5 m USB cable does not cause any problems. I read in the post “Unlocked Z Nut Lock” that you are after a “new z nut lock”. I would like to get a notifier when such important updates to the MPcnc are published. Can I subscribe please :wink:

On the new one I took off the spring and small nut. It seems to cause people to many problems. Those that want it can add it if they want.

In the updates forum, version 2 thread we have been talking about new parts for a while. The parts will be available pretty soon but only for the brave souls who want to give it a test run. after we get some confirmations that it works, and it is actually better I will change the parts on thingiverse and update the instructions, and make new tool holders.