Z axis keeps locking up

[jbalat]

I am doing a 3 day print, after day 1 the printer gets locked in z and keeps printing over itself, basically a big mess
I press pause
After I resume it goes for another day without issues
Day 2 printer locks up again
I press pause and restart then works as normal

I originally leveled the x rail to the frame but after the first lock up one side was 3mm higher than the other, now it’s only 1mm out.

I assume that the x rail becomes skewed but can’t be sure, not sure why after resuming everything is ok again

[William]

Hi, you can see if the z-axis threaded rod is bent,
Regarding whether the z-axis guide is stuck or whether the pulley is worn.

Is it possible to print a test model.

[jbalat]

This is a new printer so nothing is worn

Is there an easy way to check if the z rods are bent ?

[William]

This is a new printer so nothing is worn

Is there an easy way to check if the z rods are bent ?

Hi, It can be removed for inspection on a flat surface.

[SerpentWarrior]

I had a similar problem recently with the Z axis and thought one of my Z axis motors was dying. Turns out (pun) that the coupling that holds the rod to the x carriage was too tight (???) so I loosen it and the printer started working like normal. This didn't happen right away but over time it just started to have problems. How I found the solution was when I took out the Z axis motor that was the problem and tried turning it by hand it moved easier. Not as good as the other Z axis motor so I am assuming there was some damage done. When I tried to turn the rod by hand it still wouldn't turn.

Maybe give that a shot. I could hardly turn the threaded rod by hand. The entire thing felt seized up.

[jbalat]

thank you, i did loosen off all the screws on the brass couplings and i moved the rail down and loosened the z motors and tightened them back up again. I have run it all the way to the top and down again a few times with some lubrication and it seems ok now. I wont really know until I do a very big print again but its printing ok for now.

[SerpentWarrior]

That is great to hear! I would recommend trying to turn the rod by hand after disconnecting the motor wires. This is to get a feel for how much resistance there is. It should be relatively easy to turn the motors. Like you, I tried running my Z axis all the way up after I made the changes. I found my X carriage was canted a bit and caused some terrible sounds as the A30 protested my request.

<rant>
I feel lucky to be able to use my printer again! I have a problem with it rebooting all the time though which is causing layer gaps on smaller prints. It would be nice if there was a way to prime the hotend with filament after a pause or power failure. </rant>