Second print head skipping

[cregenpri 0]

Hi everyone,

First of all, sorry if this has been posted before, I tried searching for hours to no avail.

I've had my UM3ex for a week now, printed a few things with single extrusion, and 1 part with dual extrusion using PVA which turned out pretty well.

I'm trying to print a business cards, and the second print head, which is AA like the first one now, both with PLA, is slipping and not printing well, for example, letters are not fully printed, just parts of them.

I calibrated the table 4 or 5 times in the last 24 hours, I think I'm doing it well, because single extrusion printing works good I think. The first part of the card came out well, but when it came to switching heads, it wasn't as good. I will try to attach as much as I can to help describe what my issue is exactly.

I turned autoleveling off completely.

The card base is 1.5 mm thick, the embossing is 0.63.

Maybe it's just a design fail on my part? I've read something about Z hop? maybe I need to configure that? Print settings were default High Quality

Video of the beginning of the print (there is a weird noise, which I think is the print head touching the glass? it is better now, than it was):

https://1drv.ms/v/s!AuHDxxAooCFChoZOeA01qOF7X08a1w

Video of the second print head slips:

https://1drv.ms/v/s!AuHDxxAooCFChoZQPVWENJHBBIP9qg

This is what it looks like in Cura:

https://1drv.ms/i/s!AuHDxxAooCFChoZU4a7Vr_eQ42iX9w

This is what came out printed:

https://1drv.ms/i/s!AuHDxxAooCFChoZTb_rtAJDK0llV9g

Thank you in advance!

[Nicolinux 288]

Hi,

it could be that the letters are too thin and Cura "slices them away". In Cura select the "layer view" on the left side (the button with the eye on it).

There you can scroll through layers and see what will be printed. This view is super useful - you should always check it before a print.

[cregenpri 0]

oh my gosh. that was it! in layer view it shows up exactly like it was printed. THANK YOU SO MUCH! may this be the cause of the skipping as in the video also?

[Nicolinux 288]

I didn't spot any skipping in the video. When you talk about skipping, I think of the case where the filament can't exit the nozzle because of a partial clog or other problems in the bowden tube. The extruder motor then skips back because it can't push the filament further.

[cregenpri 0]

Apologies then. I'm not sure what the correct word would be. In the 2nd video, when it starts printing with the 2nd head, it moves like as it would slip. the head moves slowly and then it's like it slips on ice and moves fast to the next point. It shows best at 0:45 I think. Also, the beeping, is it a bad thing? I assumed it beeps when it collides with something or the motor faces heavy resistance

[Nicolinux 288]

This is ok, no need to worry. The fast moves of the head are called "travel moves". You see them in the Cura layer view as blue lines. That's when the print head needs to go to the next area and print there.

The beeping is a retraction move. This is no problem either. Retractions are performed mostly in combination with travel moves in order to avoid oozed filament to get in the way and stick to the printed object.

There are tons of slicing parameters in Cura which can influence these moves. But it is recommended to stick with the defaults until you feel comfortable with the printer.

When you are ready, access the settings in Cura and enable some (or all) slicing options. Then softly say "OMG so many!" and then faint

Edited March 2, 2017 by Guest

[cregenpri 0]

Okay.I was having doubts about my calibration. It's just that sometimes the whole frame shackes and it scared me. Thank you!