A little stuck here.

I got my Taz4 a couple days ago and am a little stuck. I installed the software and have aligned the bed (not real happy with the Z-stop, seems a bit inaccurate and finicky but will work on that later). I have pronterface working and planned to start with the files on the memory card. The nozzle is .35 and I am using ABS, and have tried printing the Small Octopus ABS file with little to no success. It seems that by the time it gets through a couple of layers It is having filament feed issues, namely it is wearing a groove in the filament so it can no longer feed and it just prints in the air so to speak. I’ve tried all different tension settings and even raising the extruder temp to 245 with no success. Ive tried Jet ABS and IC3D brand ABS with same results. When the extruder feeds properly it seems to work ok but that doesn’t last for long as it ultimately ends with the feeding problem. I’m sure I’m overlooking something, what else on the machine or in pronterface should I adjust? What about print speed? Pronterface defaults to 300mm/min I believe, is this range realistic? Any help will be appreciated. Thanks, Greg

Don’t raise the temp above 235C (or 240C) on a Buda or you can damage it.

Support can help with your other questions, I just wanted to make sure you knew about the temp.

Take a look at: https://forum.lulzbot.com/t/show-off-your-printer-and-printing-station/48/1

I posted an idea on how to increase airflow through the heatsink of the hotend assembly. You may not need to go to this extreme. So far this is working wonderfully for me.

Many theorize (including me) that jamming may be caused by heat creeping from the heat chamber up into the region where the heatsink is. Heat softens the plastic and deforms it in this region – Thereby creating an eventual block --> Plastic filament has no where to go --> you see knurled bolt eroding filament. The idea of ensuring air flow is to improve the cooling function of the heatsink.

Do Not Increase temperature beyond 230 C as warned by previous poster. If the heat-creep theory above is right, you may be worsening things by going higher. You may want to increase extrusion speed higher than the default 30mm/s. I’d experiment with 10-15% higher for now (who complains about a faster printing speed anyway?). The faster speed allows more material to run through thereby dissipating heat. Also, you do not want to idle your hotend too long before start of print (obviously to help reduce heat-creep again).

No need to over tighten bolts pressing filament to knurled bolt. If the heat-creep problem is controlled, the recommended tension listed in manual will suffice.

Good Luck. Let us know how it goes.

So, I set the temp to 230 and little changed. I’m simply trying to print the small octopus abs file from the SD card, not sure exactly where to change the extrusion speed, as I’ve seen it in a couple places.

One thing that seems wrong is that when raise the extruder and extrude in air, I don’t get a stream of filament but rather a glob on the end of the nozzle. It also takes WAY longer for the material to come out than it does for the machine to feed the filament. What I mean is that with the extruder in the air, I use the ‘extrude’ button in prontface to feed 5mm, which takes a second for the stepper to do that, but the material keeps squirting out for several seconds longer. It’s sounding to me like the nozzle is no good.

It seems as it is now I can’t even get the bed calibration print to work. This thing jams literally seconds into trying to do anything.

you know those two thumbscrews you tighten down after you put filament in? That might be too tight if you cranked them all the way down. I believe there should be 8-10 mm of spring visible.

I have never printed from the SD card.

You should try printing something else and not use the SD card.

Download something small and simple from Thingiverse. They have the octopus there if you really want that. :slight_smile:

Bring it into Slic3r. Use one of the ABS profiles from Lulzbot. Start with the medium setting. https://www.lulzbot.com/support/taz-slic3r-profiles <-- clicky

Create your gcode, then use Pronterface and print.

Sounds like you also have a clogged nozzle. An obstruction is likely causing plastic to extrude at an angle and causing all the curling and bunching. I resolved a similar issue by soaking nozzle in acetone overnight, cleaning all gunk and ensuring an ultra clean nozzle. Even new nozzles need to be inspected and cleaned before install. Use high temp antiseize when reinstalling to make it easier to replace in future. Follow instruction in manual to detach nozzle. Be careful not to cross thread as you unscrew.

How compressed are the two springs on the extruder? Also, in Pronterface on the lower left hand corner, what is the manual extrusion speed set at (mm/min)?

If you think your nozzle is clogged, before you do anything please send in an email to Support@LulzBot.com with the following information:

  • Order number

  • 3D printer serial number

  • Contact information

  • Shipping information



Manual extrusion speed is set at 300, also, I have tried various adjustments on the two screws on the extruder. I’ve just sent the email, thanks.

It’s a good bit harder to correctly dial in your extruder idler tension when manually extruding at such a high rate of speed (300). Turn that down to about 150 and dial in your extruder tension like described in the quick start guide.

Aren’t those extrusion speeds, and feed rates, and pretty much everything else something that is pre-set in the ABS profiles from the Lulzbot webpage that I linked to a few posts back?

I seem to recall seeing settings in those files that had slower extrusions rates for outside perimeters, and faster rates for infill.

That is correct. But what we’re trying to do here first, is verify that the extruder idler is properly tensioned. It’s best to do that at slower manual extrusion speeds (150-200, not the stock 300 in pronterface). Once that’s verified, then the extruder should be able to extrude at whatever speed the gcode asks it to.

If the tension on the idler is incorrect it will fail. If the tension is too loose, it will chew out during extrusion stops/starts, similarly to peeling out from a stop sign. If the tension’s too great, it can chew out the filament during a lot of retraction moves, as the filament’s being moved back and forth over the hobbed bolt. It’s best to do this by minimizing variables, so we manually extrude, at a lower rate, in the air and adjust the tension until extrusion is reliable and repeatable.

Any updates? Any reply to your email? :question:

Sorry about the delay, I work week-on/week-off Thursday to Wednesday and have little time to do anything but work during that stretch. I’ll get back on this Thursday and see how it goes.

Yes, I got a reply to my email. The email contained some things to try but I have not had a chance to try any of them.

Massive leaps forward today. I’m printing ABS at 215C and it’s working great, I wonder if my temp readings are a bit off and what I thought was 230 was higher and causing the heat creep issue. I did the PEI bet upgrade and using some aquanet I’ve had success. My biggest failures have been errors I made modeling the parts, then printing the incorrect part more than once.

On another note, I’m considering a flexystruder, can anyone tell me if ninjaflex would be a good material for RC truck or buggy tires?

Glad to hear you’re up and running.

Ninjaflex it rather awesome, and can work well for tires and such.

Do you know if it can be glued/cemented/solvent welded to ABS?

When printed onto ABS/PLA it bonds exceedingly well. Super glue would probably work for adhering parts together, but I can’t speak of it’s effectiveness.

Ninjaflex would be great for tires.

About the flexystruder - not necessary. I drilled out the filament hole in my stock extruder body and pressed in a piece of PTFE tubing. I cut the top of the tube into a flat wedge that would fit between the hobbed bolt and the idler bearing, but would still leave enough room for the bearing to press the filament against the hob.

I’ve printed ABS, ninjaflex, PETT (T-Glase), and Nylon 618 without a problem using the one modified extruder. It’s nice not having to change extruders when I change filament; plus I expect the PTFE tubing will not wear out, since the side load is taken up by the idler bearing.

Behold: a $0.50 flexystruder!


Fimjabbi, care to share some photos?