layer alignment

[mjmdavis 0]

Hi all,

I've been having some trouble with rough prints on my UM2+ (UM2 with upgrade kit).

I'm wondering what could be causing it or if it's normal. I don't remember this happening in the past...

examples:

Could it be that I have a loose grub screw on my x or y axes?

Are there any tricks to tightening those? During the UM2+ upgrade process it was tricky to get everything aligned correctly. My hands didn't fit inside the printer.

Edited June 18, 2017 by Guest

[Siebet 27]

Hi,

I have the same problem.

My prints are a little bit better but not awesome!

How can I fix this?

This print was made with 0.1mm layerhight...

[6maker 10]

Hi all,

I have the same problem with our Ultimaker 2+ with dual-extruders.

Is it possible that poor cooling of the nozzle generates a non-constant plastic outlet?

Or a poor quality plastic?

Have a good day.

[Siebet 27]

Hi all,

I have the same problem with our Ultimaker 2+ with dual-extruders.

Is it possible that poor cooling of the nozzle generates a non-constant plastic outlet?

Or a poor quality plastic?

Have a good day.

It could be a problem with the cooling. My overhangs are also bad! But my fans are on when printing...

[gr5 2,172]

This is a common problem with printers as they get older. It looks like typical Z axis issues. Sometimes the Z axis doesn't move as far down as it is supposed to and so that particular layer will over extrude and stick out like an expanding pancake. Then on a future layer the Z axis moves too far and you get an underextruded layer. This pattern repeats in a somewhat random pattern. Often at the exact same height for different parts.

Try cleaning your z screw. That is often all you need - just a papert towel and a long fingernail to shove it in the threads (it's a triple helix so make sure to get all three channels). If that helps a bit that should encourage you to take it all apart and clean it thoroughly with wd-40 then dry it then give it a drop of fresh grease. While it's apart move the bed up and down and check the vertical rods and bearings. Sometimes that's the problem. If none of those things help then the Z nut is probably worth replacing. Many people have seen remarkable improvements by moving up to a more expensive Z-nut (typically 1€ or 1$).

[mjmdavis 0]

@gr5 thanks! That seems obvious as an explanation now ^^. Can you recommend a Z-nut for a UM2?

I'm excited! I had been considering printing a bunch of stuff on shapeways for a project but 1 Euro sounds pretty doable.

[neotko 1,417]

I would check the hotend temperature to see if it's really stable or it's fluctuating.

Also um2/um2+ firmware doesn't have PID (temperature control to have it more stable) so I would try to install Tinkergnome firmware that does and relaunch the same print to see if it makes a difference.

More about the banding and sources:

https://ultimaker.com/en/community/20188-smooth-walls

[Siebet 27]

Hi,

I have cleaned my z-rod and I used the Tinkergnome firmware to run the PID setting.

This helped a lot! Chek my new prints! (Green=> before / Gold => after)

Thanks to make my Ultimaker back an Ultimaker!!

Edited June 23, 2017 by Guest

[mjmdavis 0]

While cleaning the Z-Screw, I noticed that the bed bearings are in fact sticky. The bed will stick at certain points when I'm moving it up and down and will require significant force to get it moving again.

Could it be that I have defective bearings on the Z axis?

[gr5 2,172]

Could it be that I have defective bearings on the Z axis?

Absolutely - this is common as well. I would start by removing them and cleaning them with WD40 and drying them thoroughly and see if this helps.

Also it could be that the 2 rods are not quite parallel and loosening the bearings, then sliding bed up and down a bit and re-tightening the bearings to the bed will fix it.

If not contact your reseller or get some better quality ones if you are still under warranty. They are only about 15€ I think if you get them through a 3rd party. Neotko posted somewhere else in this forum I think where to get good ones.

[neotko 1,417]

Sure. Was on this post

https://ultimaker.com/en/community/11123-z-axis-layer-error?page=last#reply-130203

[JohnFox 25]

I have had this in the past, it was due to grease on the Z pillars. Wipe them dry with kleenex and the bearing should roll OK. If they are oily then the bearings will try to slide, not roll.

While cleaning the Z-Screw, I noticed that the bed bearings are in fact sticky. The bed will stick at certain points when I'm moving it up and down and will require significant force to get it moving again.

Could it be that I have defective bearings on the Z axis?