Fault line through print

[clinton 7]

I'm only on my second print since I've had my Ultimaker2 printer but on both prints I've had a similar fault. The first test print was the stackable cup and that had a line about 1cm from the bottom where the layers don't seem to have stuck and with very little pressure, the cup split at that point.

I'm now printing the famous articulated elephant and that appears to have a similar line round it but not at the same point - probably about 1.5cm from the bottom this time. All the rest of the print seems OK but it just seems to get the jitters at one point in the process. I'm using the issued grey PLA so the line is visible as a lighter shade than the rest of the print. I installed the latest firmware last night after the cup print and before the elephant.

Any suggestions please?

Thanks

Edited January 13, 2016 by Guest

[SandervG 1,521]

Hi @Clinton,

I think it is more likely that there is something with your bearing than with the filament.

If the Ultimaker is turned off, and you manually move the Z-stage up and down do you feel any signs of friction or resistance?

Do you see any debris or dirt in between the threads on the threaded axis?

You shouldn't need to oil the bearings, as it is more likely it will clutter the balls inside the bearing than make it move smoother.

Looking forward hearing from you!

[SandervG 1,521]

Just in case; do you just use the files from your SD-card or did you modify the temperature or speed or anything else?

[stu_le_brew 42]

I would also sugest checking the two side fans on the print head, they should com on a few layers into the print.

I had a problem like this from the start when my printer was new (two years ago !), the real problem when you are new to this game is that you do not know what the printer should normally do, it took me ages to understand that the fans were my problem

and by the way - welcome to the forum

[clinton 7]

Thanks for your comments.

The cup was taken directly from the SD card with no changes.

The fans don't start immediately the print starts but come on very shortly afterwards.

The sticking Z sounds likely. The printer has been whirring away behind me today while I've been working and I'm sure I remember hearing a clunk early on so maybe it is the Z axis sticking. The elephant is nearly finished so I'll make the checks as you suggest and report back.

It's good to have people to talk to on the subject. Cheers

Edited January 13, 2016 by Guest

[stu_le_brew 42]

its really hard to describe sounds in words - so here I go the z axis is like a "bzzurt" sound and of course will be at the same point as each new layer is started.

The other sound which would be from the extruder feeder is more like a "tock" sound, this would indicate a potential problem with the filament getting to the print head. You do not seem to have any under extrusion issue here though so it looks OK

Edited January 13, 2016 by Guest

[clinton 7]

I'm running another 40 minute print of a right angle bracket it'll have a bit of height quite quickly so I'll see if I get the same fault line.

Just heard the "bzzurt" sound

[clinton 7]

It's done it again. About the same place so it does seem like the Z is sticking/jumping.

I've done a few manual raise/lower the bed runs before this print and it seemed OK.

[clinton 7]

Fingers crossed it may now be OK. I manually exercised the bed up and down a few times near the top of its travel using the wind-round control on the front. The manual raise lower on the maintenance menu didn't take it high enough. This test print is only 20mm high but it's higher than where the fault occurred on the previous prints.

Another bracket print I think for a test.

Edited January 13, 2016 by Guest

[stu_le_brew 42]

starting to look like contamination on the Z screw, sugest try cleaning with a tissue while moving the print bed up/down - look for dirt on the tissue after

[clinton 7]

Several more prints later and all is great. Thanks for the advice stu_le_brew and SandervG. It must have been contamination on the Z screw.

Only had this thing for 36 hours and I wonder how I ever survived before without one! The list of things I want to make gets longer every minute.