Layers skipped, possibly Z axis hangs?

[lizzard77 0]

Hi folks,

I had hoped my first message would not be one about a malfunction of my cute new UM2GO, but sadly, I'm experiencing problems. My prints show a gap at certain (constant) heights:

I've already cleaned and greased the Z axis trapezoid screws. Manually moving the print bed up and down, I can't feel extraordinary resistance at a certain point. I've also set all currents to 1200 mA, as advised by Ultimaker's German support rep, to no avail. I tried like five different filaments, different temperatures etc...

I'd be happy if anyone had a suggestion - I'd love to be able to print anything higher than 12mm.

Thanks, Phil

[SandervG 1,095]

Hi,

Thank you for your post and welcome to the forum.

I was wondering if you had this under extruded line on the exact same length every print or does it vary? It kinda looks like it varies, and on some of your prints it looks like generic under extrusion. Which makes me think it may not be the bearings.

Could you tell me what settings you are using?

What material are you currently using, and what materials have you used in the past?

Looking forward hearing from you!

[oppyfromoz 0]

I have a similar problem at 14mm on every print. I have tried to log my issue yesterday but i notice it is not logged. I will keep track of your responses and hopefully I will resolve mine at the same time.

Cheers

oppyfromoz

[lizzard77 0]

Hi -

thanks for the warm welcome.

The first skip occurs at 10mm in most prints (there were two out of 10 prints that didn't have this one), the second at 13mm height (in all prints I made in the last few days). From there on upwards I've also had the impression of constant underextrusion, but this might be due to my tuning efforts.

I've used the following filaments (all PLA @2.85mm): Ultimaker's own (silver), Prima Value (black), Das Filament (pink), eSun (brown). Currently I'm printing the same test cube from the SD card using the brown filament from eSun.

Could "simple" underextrusion occur at the same height every time?

Thanks for your time and efforts!

Phil

[lizzard77 0]

PS: Settings are back to default - PLA @210°C, no alterations to the machine's default in regards to material flow, retraction etc.

Phil

[SandervG 1,095]

Hi Phil,

Because you have tried so many different filaments, can I ask you try an Atomic method to make sure your nozzle is clean from the inside?

You can find a tutorial here on how to do it.

It could be that small particles/dirt are interfering with your material flow.

Alternatively, I would suspect the bearings on your Z-stage but first things first

Lets get that hot end nice and clean first!

[lizzard77 0]

Hi Sander,

I really appreciate your help!

Alright, I cleaned the nozzle, the first run did remove some dirt apparently, the second was clean, no more residue on the filament piece. Then I printed one more calibration cube (guess what, I have about 20 of them sitting here on my desk) - no change, there's still a gap in the very same place.

I tried something: I ran Pronterface (the version included with Cura 15), moved the platform way up and then ran sequences of G01 Z30 and G01 Z-30 commands to slowly move it up and down, up and down. I've made a video where you can hear that there's something non-linear in the movement:

 

Maybe this helps find the reasons behind the problem?

Regards, Phil

[lizzard77 0]

Hi @all,

I'm still struggling with the problem. What I saw today is a screw protruding from the back part downwards:

Is this normal? Should I try and tighten it?

Phil

[lizzard77 0]

Okaaaaay,

this is weird, but I think I solved it: I re-flashed the firmware from Cura 15.04.4, did a factory reset, and so far I did three prints without any problems. Maybe this helps others as well - just try it.

Cheers, have a nice weekend -

Phil

[peggyb 142]

leave the screw like this, it triggers the lower z limit switch. There ia a corresponding hole in the bottom of the printer.

Great that it prints well now! Other than moving the platform with Pronterface (is the difference in sound gone now?) you can move the platform by hand. Grab it at the back and slide it up and down. Do you hear or feel anything strange?

[lizzard77 0]

The different sound and the correlated hang of the platform were only showing when moving with Pronterface. Manually moving the platform did not make any sounds, any stops, anything.

So far, I made three more prints, and all turned out fine - thanks @all for their efforts and time.

Have a nice sunday!

Phil

[taleo11 2]

Okaaaaay,

this is weird, but I think I solved it: I re-flashed the firmware from Cura 15.04.4, did a factory reset, and so far I did three prints without any problems. Maybe this helps others as well - just try it.

Cheers, have a nice weekend -

Phil

 

Hey Phil,

I've been having the same problem as you with my umo+ where cleaning the z rods also didnt work for me. How did you re-flash the firmware and do a factory reset? I'm still kind of a noob when it comes to firmware issues.

Thanks!