Nozzle runs into print

Hello,

The current issue that I am working with my printer is getting the nozzle to not run into the print while it is printing. I have read a few other threads about this same topic and none of their suggestions have been a solution to this issue for me. Essentially, the nozzle is just too low.

Here is what I have tried:
1. re-calibrating the z-axis
2. Changed the 3rd parameter of _MAX_FEEDRATE from to 2
3. Changed the 3rd parameter of _MAX_ACCELERATION_UNITS_PER_SQ_SECOND to 10
4. In Sli3er I have changed to Lift Z from 0 to 0.5
5. Also in Sli3er I changed the extrusion multiplier, however, I wasn't seeing a difference so I just kept lowering. Currently at 0.5 which seems crazy low but there wasn't much of difference when it was at 0.9 to begin with...

I'm not sure what else to try. The nozzle is so close to the print that it will often knock the print causing the whole thing to fail, or be so close the the filament won't come out smooth.

I can provide images, video, and other details if that helps.

Have you calibrated the extruder?
If you went from .9 to .5 that should make a HUGE difference.

Oooooohhhhh! That's what I was forgetting! Will attempt tomorrow and report back.

Okay, I have re-calibrated my extruder @ (i.e. 10mm extrusion is actually 10mm of filament going in) and the prints look better, however the nozzle tip is still rubbing against the top of the printing object. The rubbing is audible, and at that point I just stop the print because the filament isn't able to come out well since the tip of the extrude is too close.

Any additional suggestions?

Do you mean the 2nd layer is the issue?
What is your layer height, nozzle size, Z offset etc. ?

Yes, well its more a a 3rd+ layer problem the second layer is acceptable.

Layer height: 0.3mm
First Layer height: 0.3mm
Nozzle diameter: 0.4mm
Z offset: 0mm

Does fit with a poorly calibrated Z axis. If you request movement to z=100 do you get 100. Since you have zero in the Z offset (should be the distance between the bed and nozzle when homed [set during bed levelling]) usually about -0.15 for paper, your 1st layer is theoretically too large but if your z is calibrated low it will effectively counteract this until layer 2 or 3 when you are effectively over extruding. This may also explain while the multiplier is having less effect.
This assumes if you request 100mm you get a lower value.
Is Z missing steps (clicking), this can be due to insufficient current and could be due to a PSU issue. Calibrate the Z axis with the hot end on to ensure you have the same power drain as when printing.

Thank you for the suggestions. Great idea to calibrate the the z-axis with the hotend on. That actually did change the distance displaced. It moved about an extra 8mm. So with that fixed, I managed to get the absolute best print I've ever done! Everything is fixed! For now...


Thank you!

8 mm? Holy Moly... I think you wanna say 0.8mm, this is still alot.

Nope, 8mm.... I know, yikes. My printer does some funky things.

Wow. The difference from non heated bed & extruder to both heated at my Mendel is about 0.4 or 0.6mm. Anyway, you get good prints now, congrats!

Edited 1 time(s). Last edit at 07/05/2017 05:04AM by Inhumierer.