Whats up 3D printing world! I’m having some issues with my printer. Up until recently, everything was printing good. However, I’m now having a random issue, where the first few solid layers will print very well, but as soon as the infill starts, my printer stops extruding and starts stripping the PLA filament. I’m thinking maybe I accidentally changed a setting or something and I’m wondering what could be causing this to happen every time, really early on in the print.
A) Read both of the guides in my signature for helpful strategies on how to deal with issues like this
B) You need to provide more context - which printer, extruder and hot end?
C) From my limited experience with a TAZ 4/KITTAZ and Budhashnozzle with 3mm PLA filament I’ve experienced this “eating of the filament” issue 3 times and all 3 times it was due to printing too fast and not having enough tension on the Wade’s extruder’s tension springs. Read the guides, SLOW DOWN first and then, as a second step, apply more spring tension. Once you have it sorted slowed down and more tension, then you can start to gradually ramp up the speed again. That’s where I am now and I’m able to do 5+ hour prints at >60mm/s with PLA with no problems.
First things to check would be your -
1:Print speed
2:Retraction Settings
3: Tension on the Hobbed bolt
I’ll bet your issues lies in those things.
Can you post your slicer configuration? Chris’ suggestion of retract speed is a good one, for PLA make sure that is on the low side, I print 25mm/s retract for PLA. With KISSlicer you can have a separate speed setting for prime (the opposite of retract) so I run at 25mm/s retract, 50mm/s prime. I’ve written a lot about PLA and it’s thixotropic properties and why fast retract is bad and frequently leads to plugged hot ends. This would most likely appear printing infill so a good catch by Chris.
Hey guys, thanks for getting back to me. I’m still really new to this so I only have half a clue what your talking about, however I can get more specific. I have a Taz 4, uses 3MM filament. I also upgraded to the dual extruder, and I just put it on a week ago. That’s when I started having this problem with PLA as well as ABS. I posted a picture to show you guys what it’s doing. What is the hobbed bolt??? And should the nozzle diameter be set to 5mm or 3.5mm for the ninjaflex dual extruder?
The nozzle diameter is dictated by… well the diameter of your nozzle opening. 
I think its .5 for the flexystruder… Check the product page of the dual extruder.
The hobbed bolt is a special bolt with teeth cut into the side and is attached to the large herringbone gear. Its purpose is to grip the filament and feed into the hotend. More info here.
The idler applies pressure on the filament to ensure the hobbed bolt grips the filament. See assembly instruction above for more info and visual.
Looking at your picture, it looks like the filament isn’t extruding because of a clog or the temp is too low. If the temps are too low, the filament won’t melt fast enough to keep up with the required extrusion speeds. If clogged then you won’t get the proper mount of material. PLA has a tendency to burn if extruded at high temps. Or more commonly, if you heat up the filament and just let the hotend sit there without extruding any material… it will burn.
To clear the clog, you need to do a “cold pull”, which “cleans” the interior of the nozzle using the filament itself. The process is to heat up the hotend to the get the filament liquified, then cool the hotend and pull the cooled filament out. The idea is to pull any debris inside the nozzle out with the cooled filament. Obviously, cut the end of the filament off so you don’t put the debris back into the hotend. A detailed post of the cold pull process can be found here.