Jump to content
Ultimaker Community of 3D Printing Experts
Kwallnation

Uneven layers? Although I print at .1 mm I am still able to see every layer...help please

Recommended Posts

Hi,

So I've been printing with the UM2 for about ten months now and recently it has been printing uneven layers. It looks similar to how under extrusion looks, but the layers are solidly formed. As a result, I can see all of the layers that it prints. They are not flush up against one another and seem to look a bit staggered. I replaced the Coupler two weeks ago so that is not the problem. I have also done several atomic cleans and am using Ultimaker Filament. Does anyone have suggestions on how to fix this? I suspect that it could be due to difficulty of the feeder to turn the new spool of filament, but I don't know for certain.

IMG_4492.thumb.JPG.c166e5faaff57db69e828bedb92339ff.JPG

IMG_4491.thumb.JPG.73fb990d0b33c1ffd26490f0b3967512.JPG

IMG_4493.thumb.JPG.ef0a06bb2761413002f4962902ccd697.JPG

Thanks for the help!

IMG_4492.thumb.JPG.c166e5faaff57db69e828bedb92339ff.JPG

IMG_4491.thumb.JPG.73fb990d0b33c1ffd26490f0b3967512.JPG

IMG_4493.thumb.JPG.ef0a06bb2761413002f4962902ccd697.JPG

Share this post


Link to post
Share on other sites

I just checked and I did properly grease the z-screw. Also I printed a lightsaber (both skinny and tall) which was the one print that printed extremely well on the almost empty spool. I believe the height of this print would have come out much worse had the z-screw been the problem. Therefore, I am back to believing it is a problem with the spool. Could it be that the filament on the spool is not wound tightly enough?

Share this post


Link to post
Share on other sites

If you are running the stock feeder you may need to pull it a part and give it a good clean.

Have a look at the impression of the feeder wheel on the filament, To much and the filament will be squashed flat which makes it tight in the bowden, not enough and it can slip. About 2 pyramid imprints side by side should be about right.

Share this post


Link to post
Share on other sites

If you are running the stock feeder you may need to pull it a part and give it a good clean.

Have a look at the impression of the feeder wheel on the filament, To much and the filament will be squashed flat which makes it tight in the bowden, not enough and it can slip. About 2 pyramid imprints side by side should be about right.

 

I laid the spool on the floor and the problem seemed worse. Are there any more suggestions that you have?

Share this post


Link to post
Share on other sites

It's a bit of a sod to get at the bolts holding the bearings, one needs fingers the size of a mouse. Not convinced it is due to the bearings though, that fault seems to be under-extrusion on the odd few layers, not over the whole model. However, I would wipe the Z axis pillars to remove any oil just in case. Have you any strands of old filament along the length of the Bowden tube? Just wondering if it is friction along the tube. Do you get any 'tocking' sounds from the feeder drive?

 

I just replaced the PTFE coupler two weeks ago, but I will check the bearings. How would I access the bearings?

 

Share this post


Link to post
Share on other sites

That's probably due to friction on the feeder/bowden tube somewhere.

Looks like highly variable extrusion, sometimes under then over.

Regarding spools of filament, normally the ends of spools are worse because the diameter of the spiral is much smaller and it is harder to push the tightly curved filament down the tube. I have switched to coils because of that.

Could it be temperature variations in the nozzle - anyone?

Did this problem occur before or after you replaced the coupler?

 

Yes, there are some "tocking" sounds but only on the first few layers.

 

Share this post


Link to post
Share on other sites

Have you measured the filament diameter? You may have 3mm filament that is actually 3mm or slightly larger, and the varying diameter of the filament can cause variable friction in the Bowden tube and PTFE spacer, causing random under-extrusion.

For the Ultimaker, you Must use filament that is 2.85mm, not 3.0 mm. Ask the vendor before you buy...

Edited by Guest

Share this post


Link to post
Share on other sites

Probably not the filament at fault then.

Just wondering if you have a problem with the sensor, hence the question about when you changed the coupler, ( and disturbed the sensor cable ). If the sensor is giving false readings, then the controller will try and adjust the temperature to what it thinks is 210C, making it over and under extrude. Going to be hard to prove because the sensor reading will probably show 210C even though its not.

 

We currently use 2.85 mm standard ultimaker brand filament.

 

Share this post


Link to post
Share on other sites

This is most likely your Z stage. It could be that your nozzle is varying by more than 10C in temperature slowly - so check that first as that's easy to test while printing. and it could be filament that varies wildly in thickness. But most likely it is the Z stage. Probably the linear bearings and not the Z screw. You want to keep those vertical rods very clean and no oil is needed - in fact it's better if there is some friction as the ball bearings like to roll and if they don't roll or get clogged with oil it can be a problem.

I recommend taking it apart and removing the 2 vertical bearings and cleaning it out very well with WD40 and drying it completely with rag or something similar and making sure they slide nicely and putting it back together. Other people have had similar problems and fixed it by cleaning the 2 bearings.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

  • Our picks

    • Taking Advantage of DfAM
      This is a statement that’s often made about AM/3DP. I'll focus on the way DfAM can take advantage of some of the unique capabilities that AM and 3DP have to offer. I personally think that the use of AM/3DP for light-weighting is one of it’s most exciting possibilities and one that could play a key part in the sustainability of design and manufacturing in the future.
        • Like
      • 3 replies
×

Important Information

Welcome to the Ultimaker Community of 3D printing experts. Visit the following links to read more about our Terms of Use or our Privacy Policy. Thank you!