Asymmetric Print Quality issues

Hi everyone,

I work for a small engineering group and we purchased a RepRapPro Huxley as our first entry/foray into 3D Printing for making small parts here and there (and thus avoid time consuming/expensive machining in our workshop).

After a 5 month battle with calibration, print settings, slicing software, printing software, controller firmware and all manner of things - we finally have the unit printing at what we could consider an "acceptable" quality... however... we are still having some small (but not insignificant) print quality issues that are to us - inexplicable...

I am hoping people on here can shed some light as to what is happening. First...

1. Our Setup:

* RepRapPro Huxley.
* Hardware Calibrated to high degree of accuracy (X, Y, Z axes).
* Sanguinololu 1.3a running Marlin Firmware (not sure of version sorry).
* Slic3r 0.7.2b.
* Pronterface (not sure of version sorry).
* Settings we use:
- Slicer Settings (Download)

2. What we are trying to print:

* Print Files:
- STL File: STL File (Download)
- GCODE File: GCODE File (Download)

3. What we get when we print:

So basically the issue is this. One side of the print is immaculate/as we would expect. The other is quite terrible. Note the area where the holes are located - everything seems fine on the bad side!

However above and below these holes, things get ugly! This is the crux of our problem, and what we need help with!

* What we expect (the good side of the print) - note that the holes have support material inside - which is fine:


Click image to enlarge.

* What we didn't expect (the bad side of the print):


Click image to enlarge.


Click image to enlarge.

We even did a GCODE simulation in Repetier-Host and it looks just fine... so the GCODE should be OK? Note that we also ran the STL through netfabb cloud and it seemed fine...


Click image to enlarge.

In short... what the hell is going on?!?!?!?

Take hold of the assembly which moves along the X-axis and see if it wobbles - it shouldn't and if it does, this could be the cause of your problem. I had a similar experience which was solved initially by packing this assembly with a couple of small pieces of PLA on each side of the top bearing to stop the wobble. After some time, I replaced the part with this one from Thingiverse: [www.thingiverse.com]
Alan

It's probably a mechanical issue, probably backlash in whatever direction the asymetry is occurring in.
The reason it's only on one side is that the path takes up the backlash in one direction and you see it as it reverses direction.
Check your belts, watch the print and see if something seems to stop moving before it should.