Jump to content
Ultimaker Community of 3D Printing Experts

Undesired horizontal ridges on regular distance

Recommended Posts

For all items printed, I find regular irregularities.

For a cone and two vertical cylinders, ridges are seen at regular 3 mm interval. These object should have a smooth surface.

I made 2 pictures from 3 object, one with light from above


the other with low light.


I started printing last october with Cura 13.10, now I am using 14.01 / 14.03.

Ridges are present for all prints, and circular. A ridge is wider over the full circle.

Any idea how I can prevent these ridges from occuring?


Share this post

Link to post
Share on other sites

@illuminarti: it is an Ultimaker 1

@Dim3nsioneer: I have the same idea. The pitch of the Z-'screw' is 3 mm also.

When moving in the z-direction, commanded from the Ultimaker controller, a regular movement is seen and felt.

The regular bands or ridges start to irritate me, as the surface should be smooth. It happens with all objects.

There seems to be an overextrusion every 3 mm, or the plateau doesn't move regularly.


Share this post

Link to post
Share on other sites

Your z movement is not linear. If you graphed commanded-z-position versus actual-z-position it should be a diagonal line but it has this same sine wave pattern. It's not easily measured. What happens is for the thick areas, you command .2mm Z movement and it moves .18 and extrudes as though it is .2mm and over extrudes by 10%. Then 1.5mm later you command .2mm z movement and get .22 and get 10% underextrusion. I guess you could calibrate it and fix it in software by tweaking all the Z movements.

The proper fix is to rebuild your Z stage. I put a bunch of shims in my Z stage and tighted it up and locked it very tight. I even added some hot glue. I had to play with it for hours to get it so that it moved perfectly.

Of course it's also possible that your Z screw is not straight. Take it out and put it on a table and make sure you can roll it and it is straight. If it is bent, then bend it back to straight.

DSC 6888

DSC 6886


Share this post

Link to post
Share on other sites

@Nicolinux, @gr5: thanks a lot for your comments, links and suggestions.

This week I didn't have time for 3D actions, today I did some investigation.

I took out the Z screw - keeping the rest in place. The Z screw is perfectly straight. -> OK

In the plateau, I could manually move the Z nut in foreward and sideward direction. -> OK

The aluminum connector which connects the Z motor and the Z screw shows no 'flexibility' on the motor-side, but it has on the Z screw side. This causes the screw to be slightly excentric when tightened by the little screws, and can cause the wiggle I see on the top of the screw. -> NOT OK

Unfortunately the small tightening screw are not symmetrically placed, so I have to think about something to have the Z screw centered in this connector. No idea yet... Any suggestions?


Share this post

Link to post
Share on other sites

Thanks, I wrapped a little aluminum foil (household quality) arount the bottom axis of the Z crew, and yes now the axis doesn't have excess room no more. Unfortunately, the axis still wiggles (a bit less), and when the plateau is at the bottom, the wiggle really is too much.

Improvement? Yes, a bit.

Problem solved? Not yet, I'm afraid.


Share this post

Link to post
Share on other sites

Thank you all for many insights,

I have this problem on both the UMO and the UM2.

Thinner layers increase the problem.

As I see it gr5 is right:

"Your z movement is not linear."

The result is both under and over extrusion.

When you have a sledge, there will always be some friction resisting the movement of the sledge.

When you have a screw and a nut, you must have some free play, else the nut is stuck on the screw.

When the buildplate is lifted, the direction of movement is always against the friction, so the play does not disturb accuracy.

The vertical arrangement has two possibilities.

-The weight og the sledge gives a downward force able to overcome the friction so the play is always in the same direction.

-The weight of the sledge is less than the friction, thus the sledge stand still until the screw has turned so much the play is gone in the other direction. Then the screw "pulls" down the sledge opposed to the sledge "falling" constantly from the very first movement of the screw.

So I added 400g of weight near the back of the buildplate, to get more force to overcome the friction, and it reduced the banding.

Another option is the rebuild to get less friction, a better solution, but also more time consuming.

Share this post

Link to post
Share on other sites

Unfortunately the links to the original pictures don't work anymore.

ekh: your analysis could be right. So I made 2 cylinders 2.5 cm high. One 'as usual', the second with a load of 450 g at the backside of the buildplate. As the banding problem has been much reduced already, not much difference is seen, if any.

Still your analysis is correct: without much force the buildplate can be rotated is (very) little, so when the friction comes from the left and right axis, the plate could lower in an irregular pattern.

This could mean that the design would have to be changed to a setup having two screws. Difficult to realise in the existing UMO, but worth considering for future design.

So now the big question remains: how can it be sure that the buildplate lowers regularly and remains perfectly horizontal?

  • Like 1

Share this post

Link to post
Share on other sites

Thank you for your thoughts :-)

I have not thought of uneven lowering, as I expected the vertical linear bearings to be OK.

So I tried the free play on both my machines, and there was a free play sufficiently large to be a factor in the print quality.

I do not agree that 2 spindles will be the solution, because the angle precision of a motor step and uneven spindle picth could be a problem in itself.

I think the solution is adjustable linear bearings like this example:


As the link disappears in time I post a picture here:


This could be made as an upgrade to replace the existing vertical linear bearings.

Free play on the x y bearings will also result in banding.

I have seen that manufacturers also produce 6 mm adjustable bearings.

If we had adjustable bearings, we could minimize the free play without increasing the friction.

We could also adjust from time to time to compensate for wearing of bearings and axles to a certain extent for the axles and full extent for the bearings.

Adjustable bearings are attractive, I will post that in my thread to keep these ideas in the same place.

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

    • Ultimaker Cura | a new interface
      We're not only trying to always make Ultimaker Cura better with the usual new features and improvements we build, but we're also trying to make it more pleasant to operate. The interface was the focus for the upcoming release, from which we would already like to present you the first glance. 
        • Like
      • 130 replies
    • "Back To The Future" using Generative Design & Investment Casting
      Designing for light-weight parts is becoming more important, and I’m a firm believer in the need to produce lighter weight, less over-engineered parts for the future. This is for sustainability reasons because we need to be using less raw materials and, in things like transportation, it impacts the energy usage of the product during it’s service life.
        • Like
      • 12 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!