Layers are moving on Y axis

I have to print a tamper I designed for a client and I am having some problems with the print.
First I printed a 0.5mm thin wall calibration and all went well until a specific layer where the filament was too liquid(melted). I had the same problem with 3 calibration tests and I cannot figure out the problem.
I tried to print the tamper but at tle same layer as the calibration tests, the printer started to move the layers to the rear of the machine.
I dont understand if this is a Slic3r problem or my machine has gone crazy.
tamper
tamper
Settings in Slic3r:
- 0.1mm layer
- 0.9 infill
- 5 perimeters
- Randomized starting point
- Perimeters 30mm/s
- External Perimeters - 70%
- Infill 50mm/s
- 3mm filament
- 200C extruder
- 60C Bed
- cooling after the first 15 layers

Edited 1 time(s). Last edit at 07/14/2013 09:13AM by Șap7e.

At the risk of stealing Chris's expert thunder:

If that displacement on the circular part is 2.5mm your belt has slipped a complete tooth.
The walls of the other parts look uneven. I had this occur as a precursor to missing a complete tooth. The belt rides progressively higher in the pulley until it slips over.

Suggestions:
Check out [forums.reprap.org] and [forums.reprap.org].

Turn off the motors, and move the bed by hand. Check for tight spots whilst observing the passage of the belt carefully as it rides the pulley. Chances are you will see it "bulge" when the motion gets tighter.

(I assume your belt tension is roughly correct; a twangy bass note when plucked.)

I think you are right. I did not used the printer for a few days and when I move the X and Y axis I get some resistance at the point where the two axis stayed for so long time, respectivly in the HOME position.
I did moved the axis for a wile and the belt is not showing any resistance in that point, but what I observed is that if I move them fast, the fan of the power source is moving counterclockwise, is this normal?

Yes, when you move a motor it acts as a generator and puts power onto the 12V rail.

I can't explain the other effects, or how a belt can ride out of a pulley when it is tensioned. It simply can't stretch enough to clear a tooth when it has steel cables in it..

Edited 1 time(s). Last edit at 07/15/2013 07:03AM by nophead.

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