Flexystruder v2 jamming...

I’m using Ninjaflex 85A 3mm in my Flexystruder v2. The first handful of prints worked great, but now the filament is jamming and getting torn up by the extruder drive. The first time I was get it out by back it up manually and pulling. This time, it’s pretty stuck.

I am wondering if this happened because I tried a print at 210F and it getting jammed caused the teeth within it to gum up. I was able to fully clear that jam and the nozzle was flowing well.

Any have any ideas/suggestions?

Your temp is lower than what I use. I have been very happy with the results that I get at 225C. Have you been using retraction? My best results have been with retraction turned off.

If you have the filament jammed in the extruder you may need to remove the hobbed bolt to clean the teeth.

I just had this problem too. I had to take apart the entire Flexystruder v2 to unjam it. I used the red Ninjaflex sold on Lulzbot.com. What I found is that the wheel that pulls the filament in scrapes it enough that the filament breaks apart and becomes too large to pull back through the hole. It looks like a design flaw in the FlexyStruder v2.

This happened to me too.
I’ve just received my Flexystruder yesterday and it’s already jammed…
Remember me old nightmares on cheaper and lower quality machines.
Hope Lulzbot is working on this issue.
I’ll post some ugly pics.
I have to dissemble almost all the unit to get to the hot spot and remove big chunks of NinjaFlex.
Now it’s time to reassemble it. Without any instructions or assembly notice other than the mounting instructions, I have to figure it out using my photos…
Anyway, my first 3 parts were just perfect! Smooth finish and near-perfect print. For the 3 first at last.

Here are instructions on how to assemble the flexystruder:

Yes, I’ve seen this, but what I was looking for is for a service notice to avoid disassembling the hole thing.
Thanks for sharing anyway. :slight_smile:

I’ve successfully built a couple of parts in Ninjaflex last night, but the extruder jammed again… :imp:
Found that the serrated portion of the axe was not inline with the filament path. Played with the washer order (different than the assembly picture) and it was a lot better.
Print a coupe of parts again, but fail on the big one.
Looks like something interfere in the way of the filament. Maybe the FTFE tube. I’ll push it upward to the hubbed gear to leave the smallest gap possible.
I’m wondering if the esteps count is pushing too fast the filament. Maybe I can slow this down in Cura. Not a pro with it, I’m new in business…
If anyone can help.

After many tweaks, here are my conclusion:

The Flexystruder is ok for small parts, but issues are increasing with the length of filament spent.

I fully agree with kirispupis, this design is not ready for sale.
There are major flaws imho.
First: the hole diameter for the main serrated shaft is way too big, leaving a large gap between it and the housing. 8.2mm on the sla file as well as on the fabricated part vs a bolt diameter of 7.8 = .4 mm. Considering that the shaft itself may be slightly misaxed, this could represent an issue.
I’ll try building a corrected part to fix this.
Second: the unit I received was not tuned. The filament path was not in line with the hobbed part of the bolt. Need to play with the washer order.
Third: Cura’s default settings should turn off retraction and slow down the speed I think. Going backward with a flexible filament maybe tricky. I’ve also increased the nozzle temperature to 230 C (vs 222) in order to offer less resistance after the hoobed part.
Fourth: The PTFE part was so badly cut that it’s leaving a really big gap between it and the shaft by more than 1.5mm. This is neatly inappropriate.
Fifth: Construction should be modified to accommodate such maintenance and to prevent damages done on good parts.

Is there a Solidworks part / assembly somewhere so I can rework this? I really need to get this working for the next few days…
I’ve ordered an other PTEF tube and wondering if I’ll build another unit.
I’ve already spend too much time on this. Desperate. :blush: :confused: :frowning: hElP!

Try devel.lulzbot.com

I’ve been able to take the STL and import into SketchUp for modifications and cleanup.

There is another variant. Takes a bit of parts though.

Unfortunately, for the kind of work I intend to do, it is far more easier and accurate to design in context of cad part and assembly.
Thanks kcchen

Very interesting design. Thank you. I keep it as my last chance.
I think the Flexystruder may be a bit simpler design and just need a couple to tweaks to work.
I will post my modified design once finished.

Wish I could help, but I build mine from scratch and have had no problems. :blush:

Retraction and everything works fine, and no jams yet! ‘Knock on wooden head’ for luck.

I think it’s a matter of precision in the opening of the PTFE tube. Mine is just so…!
Can you tell me if your tube is like mine?
What are setups? I’m trying to print big parts, and it’s always jamming after 30 minutes.

Thanks Kmanley57!

My PTFE tube does not even look close to the one in your picture.

Can you send me a photo? I will machine it…

I am unwilling to take mine apart just to take a picture. But yours looks like the tube moved around when they drilled out the hobb bolt section. It should be a nice semicircle cut just like the picture in the OHAI guide shows.

FreeCAD files also available in addition to STLs…

Spend my Sunday on it, but it works! It’s printing for hours now… Hope it will for all of my parts.

  • Tighter tolerances around shaft and housing as well as around the ball bearings. This is really improving quality IMUO. No more shaking.
  • PRECISE cut at shaft diameter on the TPFE tube. I’m using a 3/16 in tube from an older machine.
  • Spacing between the main gear wheel and the housing is adjusted.
  • Opening on the right side of the tube is now closed with a removable piece. This should allow maintenance in case of filament overflow.
  • Addition of viewing openings on the tube. Dark material can be monitored if in.
  • Reduction of overall complexity and radius added for improved stiffness. I’m still questioning about the slight curve on the top.
  • Detail added for removing the ball bearings.
  • Include are my STL files. Still need some tweaks but usable.
    Lulzbot this was not cool. But still love my machine. Thank you. :wink:-
    This make my day! Mean all sunny my weekend… Cheer!
    albatross_extruder_body_bl01_r1.STL (1.12 MB)
    albatross_extruder_body_bl02_r1.STL (71.5 KB)

And for the community, the original TPFE diameter tube version.
Good night! :wink:
albatross_extruder_body_bl01_65_body.STL (1.12 MB)
albatross_extruder_body_bl01_65_access.STL (72.1 KB)