Surface patterned defect

I was not able to find any discussion of this defect.  There is a regular pattern appearing on all vertical surfaces.  The angle and pitch vary with the layer thickness and the perimeter of the model.  On none constant cross-section models the pattern changes when the layer perimeter length changes.  The pattern has not been observed on grossly irregular models like "busts".  A pattern has occurs with various colors of Z-abs, being most apparent on black because it show detail well and least on white that hides details.  Looking back at early prints, 10 months ago shortly after I received the printer, the defects were there but I was focusing on solving other printer performance issues.  The defect may have been getting worse over time.  

  Sample prints:

      Material: Black Z-abs     Firmware:  V0.0.5      Software:   V0.0.9.6

      Speed: normal               Infill:  light 

      Fan:  auto                      Seam:  normal

      Layer thickness: 

             Exp. 75   0.14 mm  (on the left)

             Exp. 77   0.29 mm  (in the center)

Any ideas before I submit it to Zortrax Support?                        

Looks like a basket weave. 

I haven't had that issue on the sides. The sides of the prints I do are usually smooth and the top is not. I wish the top would be as smooth as the sides but it has a weave like that just not as pronounced. 

I can't even think to as what would cause that. Sorry

What does it look like in Z-Suite zcode?

Just an idea…

Could that be some kind if slip stick effect from the linear bearings in the head? The bearings are held in place with set screws. Try loosen them up a bit. If they’re to tight the bearings can bind and that could potentially cause some kind of chatter… Btw…You have to remove the stepper to get to the screws that hold the upper bearings…

Also make sure to lube the brass bearings in the belt blocks.

The Z-code for this test model looks fine in Z-Suite.  The defect is apparent on every thing I print to some extent.  I have never been able to get as smooth a finish as with an UP!.  I usually print at 0.14 mm layer thickness,

The Z-code for this test model looks fine in Z-Suite.  The defect is apparent on every thing I print to some extent.  I have never been able to get as smooth a finish as with an UP!.  I usually print at 0.14 mm layer thickness,

Post the STL. I'll try it on mine.. We'll see what happens..

Here is the STL for the test model but all my prints have this defect.

Can't seem to get the attachment to work tonight .  Will try again in the morning.

Here is the STL for the test model but all my prints have this defect.

Still not seeing it..

It should be visible now. Btw there's new option to quick preview stl file with link [preview] ;)

@Old Frog,

Please fill the support form at http://zortrax.pl/support-form/- your main board needs to be replaced.

It looks like it, me or computer, is working this morning.  The file is attached.