busted extruder?

So I have had the printer for about a week now and it has worked well. I have been using the e-sun PLA.
Between today and yesterday I have been experiencing a lot of failures.
First, I started getting faulty prints. I would come and there would be jams. I thought it was odd considering how smoothly the printer had been running in the past.
Here is an example:

Then, I experienced a couple of jams. I have had a couple of printers and was able to clear it out easily.
However, today I came home to this:

And after that my extruder was completely clogged. I have been able to get a decent amount of the filament out but its been hard.
It seems like there is a pretty well melted piece in there and there is no way for me to get it out.
Here is a pic (sorry for the bad quality but its hard to get in there):

I am kind of blown away considering how smoothly the printer had been running until yesterday and today. Can anyone tell me how I could potentially clear that? it looks beyond jammed in there. Kind of bummed also, new printer and seems a bit early to be having such a nasty problem :-/ anything helps.

Someone will comment on clearing it out… but in the meantime…

It looks like your lidler setting is way out. One turn screw is turned much further out than the other. Perhaps it’s the angle of the photo.

I was going to say the same as Teddy. That screw on the left is backed out quite a ways. I wonder if that’s contributing to your failure to extrude.

Sadly this does happen and just happened to me again the other day. The tension screws on the idler had backed off just enough to start slipping and before I knew it, the hobbed bolt had taken a nice “bite” out of the filament and was no longer pushing the filament through the extruder.

I am not sure that is what happened in your case because I do not see the teeth of the hobbed bolt filled with plastic.

As to clearing the jam here is what I do:

I have a long small diameter Phillips head screw driver that just happens to be 3mm in diameter. I heat up the hot end and use the screw driver to push the majority of the left over filament through the hot end. If that does not work (i.e. the nozzle is clogged) I remove the nozzle from the extruder while it is hot. (Extreme care is needed to prevent burns.) Once the extruder has cooled down again I take the hot end out of the extrude and very carefully use a pin vise and hand drill the remaining filament out. I generally try to recover the nozzle by holding it up side down with a pair of needle nose pliers while heating it with a propane torch. You need to be careful if you do this as flaming molten plastic may come out of the nozzle.

You should then be able to reassemble and start printing again.

If the problem started with a failing heater block (i.e. you are no longer able to heat up the hot end) you will need to replace the heater block. Since it sounds like you have a fairly new machine, contact Lulzbot support for a replacement.

The last thing that I can think of that could cause the problem is a failure of the hot end heat sink cooling fan. Make sure that the tiny squirrel cage fan is rotating and continuously blowing on the heat sink. If this fan is not operating correctly, contact Lulzbot support for a replacement.

I hope this helps.

thanks geburges, I will try some of those.
By any chance, are there videos or photos to those steps? would help a bit. Don’t really know how to disassemble the extruder for the mini yet.

I am not aware of any videos but it is not difficult.

  • Disconnect the tool head from the wiring harness
    Remove the tool head from the X carriage (one 3mm machine screw)
    Remove the material cooling fan duct (no need to remove the fan from the duct)
    Remove the extruder from the extruder mount (two 4mm machine screws)
    Pull the hot end out of the extruder (it may be a tight fit)

Be careful with the wires. The wires on the heat sink fan are especially fragile.
Re-assembly is the reverse of dis-assembly.

It is a Mini.

Try here

We have a couple of Ohai kits for replacing Hexagon Hot Ends and they may be helpful for the disassembly steps.

You can find the TAZ Tool head here and the Mini Tool Head here

We hope this helps!

Tried pushing down. Got some success but not too much, primarily because my 3mm screw driver is not long enough. Going to try again and see if I can push more out.

You can print a handy spacer to help set the idler spring tension, which should be 8mm from the outside faces (a bit tighter doesn’t hurt too) https://devel.lulzbot.com/Easy_TAZ_Mini/daffodil/jigs/extruder_latch_jig_0.3.stl