round prints are oval

[onemorejo 0]

Hi all,

 

I am printing on a Ultimaker 2. bought appr. in 2014.  This is not my first Printer. But to be honest I never build one. I bought them assembled so I am not SO much into it. 

 

I am printing since quite a long time. This off chause does not mean I may just make a stupid mistake. As I have no Idea and as I could not find a topic wich solves my problem I dare to post this as a new topic. 

 

I am printing allot of round stuff. I have printed parts with thread, bottels and all kind of stuff. Also very fine threads with pitch of less then 1mm w/o problem. Allway with perfect roundness and very good accuracy. 

 

Since a few month all my prints are not round anymore. They are more like a oval. Squared objects are not correct in XY measures.

I calculated a little bit and it seems like all my prints are perfect in X axis. A 80mm round object stays perfectly 80.0mm in X axis. 

While the Y Axis measures appr 1% less. So a 80mm round circle measure in Y direction only 79,2mm. 

Wich results in a oval shape. 

 

I checked the belts and they are not loose. I did not use a beld spanner so fare as they realy did not seem to be lose. At least there is no noticable difference in Y and X . Also the motor belts are stiff have strong tention. 

As I have a Ultimaker 2 I tend to think that there should be no movement in the housing, so that I should not need to check angels of the housing..  I hope... 

 

Does anybody has a Idea what may chause this? 

 

One thing wich "may" be related to this is, that every movement in Y the printer ratles. Like if something is scratching somewhere. I am oiling my rails every few weeks so this should not be the reason. 

 

I am very happy to hear your thoughts. 

Thank you so much! 

 

Johannes 

 

 

[gr5 2,268]

Look straight down from above the printer - do the two rods going through the head look perpendicular?  

 

Push the head around with your hand to the center of each of the 4 sides. Do the end blocks seem to stop at the same time or is one block offset?

[onemorejo 0]

Hi, thanks for bringing up this topic... I checkt it actually measured it and found that the axis are not 90°. From what I measured on a distance of appr. 80mm I have 1.3mm deviation from 90° angle of my old scool triangle roller.

 

Wow. I did not expect this. What can be done to solve this.