Scraping prints

[canadabear07]

Hello, I cannot get my printrbot 1405 setup right. I use cura and sometimes the heated tip seems to dig into the print. I can never seem to get the Z Asix so that it is just right. What do I need to do?

[Agent0range]

The lower nut on your z prob is about to fall off. Then recalibrate your z high.

[canadabear07]

Did. Same results as before

[frankv]

Check for play in your axes, especially Z. Make sure that the Z-coupler at the bottom of the threaded rod doesn't have any movement in it.
Make sure all zip-ties are tight and don't allow any movement.
Make sure all belts are guitar-string tight.
Make sure all screws are tight, including those attaching the extruder motor to the carriage.
Once your Z-probe is right, add a blob of glue or something to stop those nuts moving.

Your orange print looks like the bed is out of level (low at the back, high at front, maybe also sloping down right to left a bit). Maybe now you've locked your Z-probe in place, this is fixed? I actually think it's easier to fix it properly than deal with problems introduced by the compensation. I first tried shimming the bed with bits of paper, but found it was *much* easier to use some springy rubber between bed and end and use the screws to level. This also means there's a bit of give before your nozzle starts gouging into your bed.

Your white print looks OK?

[canadabear07]

Seems like every print I do I have a messy first couple layers but then they clear up as it builds up. Everything looks tight. Thanks for the help guys

[canadabear07]

Anyone know what else could be wrong?

[PxT]

If the nozzle is dragging through the print the most common cause is over-extrusion. Have you checked & calibrated your extruder?
Ref http://help.printrbot.com/Guide/How+to+ ... Printer/81

Don't worry about calibrating X, Y or Z, just skip ahead to the last step and calibrate E (although read the earlier steps to understand the calculation). You should extrude about 30mm of filament in step 5.