Nozzle running through print

[harg88 0]

Hi,

 

Im new to UM and I'm currently having a bit on an issue with a UM2+.

 

The printer has just had a maintenance kit, bed calibrated and running on ABS. 

 

Even though the bed is has been set with the calibration card, the .4 nozzle drags through the print eventually causing a fail.

 

I've uploaded an image of it laying down a raft, it seems burning its way through whilst laying the next layer.

 

Any ideas on what to try?

 

Thanks

Chris

 

 

[gr5 2,224]

This is extreme over extrusion.  I don't know what is causing it.  I've seen this MANY times.  In fact I've had about 10 prints exactly like this in the last 3 weeks.  It was caused by Cura issues in cura 3.2.1 and cura 3.3.1.  I was able to fix it by doing one of 3 things (any ONE of these fixed it): slow to 20mm/sec (yuk!), turn off acceleration control (probably already off on UM2), turn off gradual infill.  Doing any one of those made the print go from this to perfect.  I don't know why.  I'm told there is a bug in gradual infill but I don't see why it would cause this issue.

 

I suspect you have a different issue causing over extrusion.  The most likely causes are Z axis or E axis is out of calibration.  If you print a tiny 1cm cube is it 1cm tall?  Or 1/2 cm tall?  It's possible for the Z to be off by 2X simply by plugging a fan cable into the wrong spot on the PCB.  Or by loading new firmware.

 

Also calibrate your extruder.  Could it be off by 2X?  Maybe move the extruder 100mm and see if the filament moves 100mm in the tube (start with filament for example half way in the bowden tube).

 

Did you change firmware recently?  Did you change feeders recently?

[gr5 2,224]

3 hours ago, harg88 said:

The printer has just had a maintenance kit,

Did that involve changing any feeder components or changing firmware?

[harg88 0]

Hi gr5, thanks for the reply!

 

The maintenance kit was the one containing the bowden tube, fans, build plate ect. now you mention the fan cable location that could be the problem, do you have a list of the ports they should be in? 

 

I cant print anything at the moment, the over extrusion causes the nozzle to pull the part of the build plate.

 

Once i have checked the fans i will look at pushing the 100mm through the bowden tube and measuring it.

 

Thanks again

[gr5 2,224]

Do you man the "plus" kit?  If so you have to download new firmware afterwards because the "plus" feeder has a different number of steps/mm for the E axis than the non-plus.  If you downloaded new firmware it's good to do a "factory reset" which sets all the steps/mm and many other settings back to default for that printer.

 

Anyway, this link shows a good explanation of where not to plug the fan into by erin from fbrc8:

 

[harg88 0]

Hi,

 

No it wasn't the plus kit, it was purchased as a plus model. Just the maintenance kit that replaces consumable items.

 

This afternoon I took the Bowden tube out, ran some G code that extruded 100mm out. I measured it at just under 80mm. Should this be 100mm of filament movement or is it enough extruded 100mm through the nozzle?