Metal plate below feeder but above extruder off slightly

Has anyone else had the horizontal metal plate that is below the feeder, but just above the extruder off kilter a little? Enough so that it tightens the hole and makes it so that filament can’t get through it to the melting area?

I’m wondering if I should remove the print head and get in there with a 3mm (or so) file to bore it out a little, or perhaps remove/loosen the screws holding the metal plate in place to push it very slightly +X to allow filament through.

I can see and access a screw on the left of the extruder, but don’t see others.

Any suggestions?

Anyone have a link to a diagram showing the screw locations and how to remove (and put back in) that plate?


The screws that hold the plate on to the extruder come up from the bottom, through the plastic, through the plate, into the greg’s wade extruder body. It looks like on the mini that you have to remove the fan to access the screw thats on the right hand side. As far as aligning it goes, you could get it a little loose and then put a piece of filament in to make sure it feeds straight. Then just tighten it up while the everything is still in line. I have never had my extruder apart on the mini. But I have taken the one on my Taz apart several times to clean it and change the nozzles. Be very careful with the screws for the micro fan. They are very easy to misplace. Speaking from experience on that one. Hope this helps. may be of interest

Anonymous - that link is AWESOME! It shows exactly what I’ve been looking for.

The top of the “aluminum plate with hex” is where my filament is having problems. I’m not sure yet if it’s that the hole in the top of the hex is too small for the filament (or rather, possibly my filament has a diameter too great - but I already successfully printed a dozen 2" x 2" x 2" objects before this issue cropped up).

So I either have blockage at the top of the “aluminum plate with hex,” or the filament is too “fat.”

I did get in there and move the aluminum plate slightly, and was able to force through some filament. I yanked it back and forth, but it still feels tight (e.g. it catches). The yellow filament Lulzbot sent with the Mini moves through easier (again lending me to think that the tolerance on the filament I’m using is out of range in the middle of the spool somehow).

I’m going to hold off on disassembling the extruder for a day, as I have new filament (a different brand) coming. I’m hoping that it’s just a problem with filament tolerance, and that it’ll work fine later tonight or tomorrow.

I changed to a different (new) roll of filament - this time Hatchbox 3mm white ABS. It had the same problem getting into the hole at the top of the metal screw (or tube) above the heating piece. After twisting the cable around for a while, I got it into the hole, though it still feels as though that piece doesn’t fit well. Or at the very least, due to the curl of the filament, it has a habit of clinging to the right wall as I push down, and thus hits the metal wall of that tube.

Anyway, I increased the temperature to 240° C and kicked off the print job again. It failed horribly - barely any filament had come out.

I pushed some of the yellow HIPS that came with the Lulzbot into the hole, and was able to get it down to the bottom of the extruder, verifying that there wasn’t a clog. (Which brings up the question - does that HIPS have a smaller diameter than normal 3mm filament? It seems to go in much easier than the justpla PLA and Hatchbox ABS…)

I then realized that the feeder cog was clogged up now that it had chewed through several filament strands. I cleaned that (and rotated it a few times) with the metal brush Lulzbot included with the Mini. (BTW, kudos to Lulzbot for including they tools they include. Big thumbs up to you guys.)

Then, I ran the job again. This time, it extruded filament and printed fine for about 1" tall of the object, but then the entire object shifted a few inches to the side, and it just made a big wiry mess. I clipped the filament, re-cleaned the feeder gear, and increased the bed heat from 60° C to 80° C for the print job, and restarted it.

It’s printing now, but seems to be doing fine. I’m hoping the higher heat on the bed keeps the ABS in place this time.

You probably need to be closer to 85-100C on the bed… at least for the first few layers.

Adjusting the idler will help the hobbed bolt grip the filament…

If the aluminum plate is skewed, disassemble the extruder… you found one screw, the other requires the removal of the fan duct.

Most 3mm filament is actually 2.85mm not sure why. Best to pick up a pair of calipers from your local hardware store. Always good to check the diameter of your filament at multiple places.

After cleaning off the feeder gear and tightening the screws to the left a slight amount, it’s been working excellently. I’ve printed 7 items roughly 2" x 2" x 2" without issue. Had some curling on the corners of the base, but adding a brim solved that problem nicely.

I’m loving the Lulzbot Mini. :slight_smile: