y-axis translation during printing

[secondsky 0]

Hi all, are just a few days that we use ultimaker and today we tried to print the stanford bunny.

The overall quality does not look bad, whereas we have not calibrated yet the machine.

But we had a problem on the y axis, which is sometimes shifted abruptly from one layer to another.

The first time was very showy, and I thought it might have touched the sensor limit and have messed up, because was very close from the origin.

But then I moved the model and it happened again.

What it is usually in these cases?

I have some hypotheses:

-sensor end of stroke

-error in the gcode (made with netfab for ultimaker)

-replicatorg error (I downloaded and installed SkeinPyPy but I still can not connect)

-a belt can be skipped (but should have happened on both sides)

Thank you all!

[ddurant 0]

Almost definitely caused by your motor losing some steps.

Common causes for this include:

- your x/y rods not being lube'ed

- too much extrusion, which can cause a blob and mess things up when the head smacks into it

- too fast feed rate..

[Daid 306]

possible cause is lose belts.

Check if the long belts are tight (they should make an *ploing* noise) and the small belts should be really tight. These can "jump" over the pullies if they are not tight enough causing the exact problem you have. I had this same problem because of a lose small belt in the Y direction.

[secondsky 0]

Honestly was not possible for taut the belts as in the video guide, and are quite soft.

I also unscrewed a bit 'the screws internal to these components to increase the tension as much as possible, but I do not understand how to get higher.

[joergen 2]

possible cause is lose belts.

Check if the long belts are tight (they should make an *ploing* noise) and the small belts should be really tight. These can "jump" over the pullies if they are not tight enough causing the exact problem you have. I had this same problem because of a lose small belt in the Y direction.

loose belts is one option, but that would show as rather sloppy prints.

maybe the printer knocked the print twice and shifted the plexi over a bit?

[Daid 306]

I printed 4 of these:

http://www.thingiverse.com/thing:10082

for my machine. Did wonders. But my belts didn't need much extra tension.

There are more options:

http://www.thingiverse.com/search?q=belt+tension

I like the design of this one:

http://www.thingiverse.com/thing:19892

but I haven't tried them

[hedis 0]

 

http://www.thingiverse.com/thing:17058

That one is really good!