Diagnosing cause of vertical lines

Hi,

I'm having a problem with my prints. There are vertical lines running up and down the print. These occur at the same place on each layer so I'm guessing that it may be a problem with the firmware or how the models are being sliced. Aside from this issue the printer seems to be printing well.

Its hard to see but you can just make out the lines in this image.
[www.thingiverse.com]

Has anyone encountered this before? I'm running Marlin on Ramps1.4, Slic3r is generating the gcode.

Thanks in advance.

... some of this can be from changing tension in the belts when 'rolling' over the single teeth of the pulley - the printed pulleys aren't perfect, so when rotating them, the belt will perform a longitudinal 'wobble' for every passed tooth ...

---

Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

Try also changing to a prime number toothed pulley, this might help move the imperfections, if any, to random positions instead of being in line.

---

_________________________________________________________________________________________

Richmond, New Zealand
Thingiverse ~ YouTube

I have this in my prints as well, running 1.8 degree motors at 1/16th micro steps.

I'm running a TB6560 driver board and Mach3, completely different setup than yours, and I get this patterning from Skeinforge, Slic3r, and KISSlicer.

I'm gonna guess that it shows more when printing at higher speeds, and shows up much more on curved surfaces and diagonal faces than it does on a flat x or y vertical face?

I believe it comes from the step signals to the motors, causing the repeating pattern.

Not personally confirmed, but I think 0.9 degree motors would have a finer pattern due to the doubled number of steps/mm.

Here's a youtube video of a reduction geared y axis.

[www.youtube.com]

I believe a setup like that would also reduce the vertical pattern size.

I think its a 'side effect' of micro stepping and motor degrees.

Edited 4 time(s). Last edit at 11/03/2012 11:36PM by Dirty Steve.

Wired1 Wrote:
-------------------------------------------------------
> Try also changing to a prime number toothed
> pulley, this might help move the imperfections, if
> any, to random positions instead of being in line.


This only works with gears or closed loop belts that complete full rotations, not the open ended belts used on our printers. Every tooth on the belt will always engage with same corresonding slot on the pulley.

Your vertical bands could also be caused by the hotend pushing inside the perimeter when doing infill, which would explain why it's always at the same place. Could you post pictures of a printed part with vertical features ?

You can try to :

- add more perimeters.
- reduce the infill perimeter overlap setting if your slicer software have one.
- slow down the infill speed.


You can immediately determine if this is what is happening by reverting print order to do infill before perimeters. If your slicing software allows it.

---

Most of my technical comments should be correct, but is THIS one ?
Anyway, as a rule of thumb, always double check what people write.

Not an infill issue for me, also visable in circles plotted with a pen mounted to the X carriage, and in single wall prints.

I get faint vertical lines too.

This coincides with the pitch of the GT2 belt, when the part is held against the belt.

I use an active tension device (I mounted the tensioner pulley on a beam with a spring to provide tension) and it rises and falls each time a tooth hits the Idler pulley.

It has been suggested that if I printed a gear ring with GT2 teeth and a bore = to the RS608x bearing, then it would smooth out the passage of the belt over the idler.

At the moment I'm not getting good enough prints to try it.

However it will change the length of the belt required.