Yea I had this issue with PLA filament. Pla is much dryer than ABS. So I had to print a dust collector and in there I put a sponge with olive oil. It will last quite a while until you have to reoil it. You aren’t soaking the sponge in oil either. It doesn’t need much.
try to tighten the extruder gear. I have a similar problem and this helped, although it still happens from time to time. I noticed the gear eats into the filament and then stops to push it through. It could also be that the gear shifted on the stepper motor shaft and is not aligned properly anymore. Does the gear perhaps slip on the shaft as soon as it gets hot?
It could be the heating block. If your heating block is not insulated well the heat will travel up. If the heat travels up that means the plastic in the motor gets a little mushy. If this happens your motor will usually just barely be able to push the filament and might make it come out stringy or not at all. I recommend the fargo 3d printing blocks if you want to try that. They are silicon covered instead of the default ceramic which I thought broke off pretty easily.
Wow! I am overwhelmed at the generosity of the people on this forum! I tried several of the strategies proposed here, and I currently have a print going that has gotten a lot further than anything has gotten in a while.Thank you all so much!
Mine is a 2X and I’m printing with ABS, so it may be a different issue for you.
I checked my fan (the 2X just has one fan per extruder) and it seemed to be working fine, so I swapped the drive gear (the gear that pushes the plastic through) from the other extruder, switched to a different reel of filament, and dipped the end of the filament in 3-in-1 oil before I loaded it. Since then, I’ve added a few drops of oil to the filament at the point where it enters the tube when I start a print. I’m not sure which one or ones of these did the trick. I ordered a new drive gear from Makerbot in case that was the issue. It was just $12 plus shipping. Anyway, I hope this helps you!
Just an update, I changed the fan and it didn’t solve it.
I was finally able to fix the printer by changing the spring on the plunger, I believe the tension wasn’t enough to drive the filament. so changing it did the trick.