MakerBot Industries

This is the second Makerbot that i have built, and I had no problems with the first one. On the first one, if I would tighten the plunger down too much on the filament then the extruder motor would jump backward sometimes and make and make a recurring buzzing sound about every second, but I just needed to loosen up the plunger and it would run fine.

On this Makerbot, it won't extrude unless I tighten it enough that it starts doing the whole "jump-backward" thing. I can't imagine that this is good for the extruder motor, but I'm not sure why this one would act this way. I am sure that I have the extruder temperature set for 220, and it is too hot to touch the extruder, so I have no doubt that it is actually heated up (plus, I wait for the readout to say it has reaches 220).

Any ideas why I would have the problem and how to fix it? Everything else works great, so I really want to overcome this issue so I can start printing with this one.

I don't have the other bot here with me because I am in the process of moving (you know you have an awesome wife when she lets you spread a Makerbot's parts across the kitchen table in middle of a move).

I have not tried other filament, but I certainly have more to try. I'll give that a go and post here to say what the results are. Thanks for the quick reply!

No luck. I switched to a new filament and still had the same issue. I bled the old filament out completely (it was a different color so it was easy to see when it was out), then I messed with the new filament for 30 minutes trying to get the plunger just right, but it would just go back to clicking backward again.

I tried doing a build when I felt like I might have it at a good tightness and it completely failed since it was clicking and extruding inconsistently.

@clothbot:
Yikes! Won't that require disassembling the entire extruder stage? I'd be more than willing to do that to fix it, but that doesn't seem to be the problem when I think about it.

If the set screw was too loose, then wouldn't it just allow the motor to easily spin no matter how tight the plunger is instead of causing it to click back? Maybe I'm thinking about it wrong. If you think that the set screw could be the issue then I will tear it down and check. So you think it's worth checking out?

You are correct :-) My bad. Thanks for that.