Layer offset when printing large prints

[cnc_paasan]

Hi,

I am having issues with offset between layers when the print is quite large and consists of straight lines.
Smaller prints and prints with flowing lines or circles do not get these issues.

The problem print is shown next to smaller prints taht do not show the layer offset.
http://imgur.com/xz93T5M
http://imgur.com/ZbJHLQ6

Outer wall at 35mm/s and infill at 40mm/s on the print.



Details:
I have tried two different filaments:
- SeeMeCNC Arctic White PLA
- 3D Prima - PrimaValue White PLA
both printing at 200C with 50C or 65C bed temp


Rostock Max V2
Stock with exception of Astrosyn dampers

Mattercontrol 1.4
matterslice
Standard quality profile from SeeMeCNC download page



Best regards

[Polygonhell]

Slow your travel speed and acceleration way down and see if it goes away.
Motion further out from the center requires the carriages to move much faster and the limits in the firmware are on the effector motion, not the carriage speed.

What's a little odd is it looks like it's not actually skipping steps, because there is no obvious lean in the print, it's possible the skipping is consistent enough that your losing offsetting steps, but that seems unlikely. The other thing it could be is some sort of resistance to motion on one or more of the towers over some portion of it's travel, or a binding UJoint, that leads to backlash. If it is something like this you should be able to feel the difference, by moving the carriages by hand with the machine turned off.

[cnc_paasan]

Thanks

At the moment:

Accelerations = 1850mm/s^2
Travel acceleration = 3000mm/s^2

I will bring them down and to some tests

Max jerk= 35mm/s. Can it help to bring this down as well?




Edit: Fixed typo