Heat Creep on Taz 6 Single Extruder 2.1 - anyone else?

Hey there,

I’m having trouble finding a solution in the threads out there so I figured I’d post here.

I seem to be having a heat creep issue similar to this thread:

The filament seems to be eaten into until the gears cannot grab anything anymore and wont extrude downward.

The above thread states the problem is solved, but the problem is for a Taz5 and though I ordered the same fan and printed the same piece (http://www.thingiverse.com/thing:1461335), the piece does not fit my extruder which is a Single Extruder V2.1

Has anyone experienced heatcreep with the same models as mine and found a good solution? Perhaps a modified version of the piece that fits a 2.1?

I’m a beginner here so I welcome any pointers or calling out my dumb questions =) cheers!

Filament jams can be caused by a number of things. Your Taz 6 has a 40mm filament fan on it already, so that’s most likely not the problem, assuming it is working properly. To more accurately diagnose the problem, we’ll need to look into the type of filament being used, the type of part being printed, which slicer you are using, and what your settings are.

Of course. I am using Cura 21.00, white PLA filament with default standard settings except for a 15% infill setting instead of 20% (needed to speed up my print). The part I am printing is actually 10 miniature container ships for a client (one STL file multiplied and spaced out into 10 rectangular shapes). I’ve had 3 failed prints in a row, all of which begin printing okay then about an hour in the filament seems to have the ‘eating away issue’ where the filament does not seem to want to go through the extruder, then it gets stuck and the gears grind away at one part of the filament and eats away at it.

Strangely I printed the same STLs with PLA four times before this issue started happening with no issue. I have since switched to INOVA-1800 in order to get this order done (with the same 15% infill setting but otherwise default), but the issue persists as soon as I use PLA.

Thanks for reaching out!!

Check your PLA filament diameter and make sure that matches your diameter setting in Cura. Check your flow % too. 95-100% should be fine. Try increasing the nozzle temp about 5 degrees and see if that helps. You may want to try reducing your retraction speed too since there will be quite a bit of retraction when moving between the 10 parts and retracting too fast can lead to filament gringing. Also make sure your idler tension is not too tight which can bind the filament and cause it to grind. Different brands of PLA perform differently and some are more prone to clogging than others. Colorfabb nGen is a great alternative to PLA that prints easy with much fewer clogging problems. Hope that helps.

I have battled heat creep jams during low flow PLA prints on Taz running the stock hot end as well as E3D V6 hotends both with 40mm fans installed. Don’t discount heat creep too quickly. It may indeed be your problem.

If you print a larger part with nice thick layers with the same PLA and heat settings and do not have jams, there is a good chance you are having a heat creep related problem. Switching to 1.75mm PLA has cured nearly all of my issues. The filament doesn’t spend as much time in the cold section and has less opportunity to heat and swell.

I have also had better luck if the room temp is below 75F.

All good points nopick. I gave up on Raptor PLA because of jamming, but switching to 1.75mm filament… fascinating. I may have to try that.

I am happy to add more info to the conversation. I always focus on posts regarding jams because I have had soooooo many problems with it.

As far as testing with 1.75mm, simply inserting a piece of 1.75mm bowden tube in the extruder body below the hobbed bolt has worked very well on one of my Taz 5 machines. That is probably the easiest way to give it a shot.

Sorry to bring up a relatively old thread but I’m having the same issue: my Taz 6 is chewing up PLA on low-flow prints. It sure seems like heat creep.

@nopick: is there a chance you could post a picture of what you did with the piece of bowden tube? Do you mean you stuck it all the way down there until it comes in contact with the metal hotend entrypoint? Were there any other hardware adjustments you had to make (like tightening the idler arm screws more than usual)? I’d be more than happy to switch to 1.75mm PLA if it’ll get my TAZ printing it reliably.

Edit: just realized I was asking someone with the username “nopick” for a pic. :smiley:

I don’t have any pictures handy but, yes, the bowden tube needs to start just below the hobbed bolt and extend to the top of the hotend heat sink.

I have had the same jamming problem on E3D hotends even with larger than stock fans. The solution there was to install the heat brake with quality thermal compound and assemble the heat brake and heat sink while the heat sink was hot. This improves the mechanical connection between the brake and sink as well as adding thermal compound to fill the small gaps. Not sure if the Hex hotend can be assembled the same way, I have never had one apart.

I can send pictures and bowden length this evening if you would like.

Thanks for the reply! I think I get the idea of what you mean, but if you get a minute a picture or two would be awesome. Was that literally all you did to print 1.75mm filament?

Yep. Insert the tube, tighten up the idler and adjust the slicer filament diameter and retraction settings. I had to retract a little more to prevent stringing.

I will post some pictures tonight.

Thanks! I’ve got a few rolls of 1.75mm PLA just sitting there, can’t wait to give this a try and see if it fixes my jams! :smiley:

Hi all. Thought I would share a couple of thoughts I have on the subject of heat creep and jams. For the purpose of the diagram i’ve created, i’m intending only to communicate generalized associations between ‘Print speed’, Hotend Temperature and filament jams’. I’m also not trying to address any of the clogging situations having anything to do with foreign debris in the nozzle tip. IE, I’m only describing jams typically associated with heat creep, where the filament becomes difficult to pull out of the head even at temperature.

In the diagram below, I’ve tried to describe the correlation between hotend temperature, print speed and risk of filament jamming. And to be clear, when I say speed, i’m simply describing how much filament moves through the heatsink at a rate. The specific numbers (mm/s) are somewhat irrelevant. The fact is this correlation exists for every type of hotend/speed combination.

There’s also another factor that is even more challenging to isolate which is filament glass transition and melting point (2 different temperatures). Technically speaking, these temperatures are not the same across all filament materials. IE, Red PLA from one manufacturer will almost certainly have a different melting point from another manufacturer. This means that the jam risk factor can simply be higher based on choosing a different filament.

Generally speaking, the higher the heat travels above the heater block, the higher the risk of filament jams. While I love the ease of printing with PLA, it has proven to be a little more challenging when trying to print higher quality (slower speed) prints. These are the times that i’ve most often experienced filament jams of this type.

Also, don’t overlook retraction settings. This can be a less than obvious factor as well. The higher the retraction distance and the frequency of how often retraction occurs, can significantly contribute to this prob. Recall, retraction is pulling the already filament back up toward the heat sink. The higher the filament that has hit the glass transition temperature, the greater the chance of it jamming in the heatsink. Example: the combination of a slower print speed and high retraction distance can lead to a jam. It’s entirely possible that without changing any retraction settings, a simple increase in speed can eliminate the risk. Conversely, reducing the retraction distance from .8mm to .4 or .2mm may also eliminate the jams. As you can see, there are a variety of ‘levers’ you can pull in order to change the risk factor of jamming.

One last factor is airflow across the heatsink. In most cases, this may be difficult to alter as the fans on heatsinks are generally fixed speeds and yield a static cooling effect at all times. This is at least in part, why you find quite a few heat sink fan shroud designs.

Sorry to be long-winded. I hope this helps some of you. Here’s Lulzbot’s extensive reference to 3d Print filament if any of you are interested in reading. https://devel.lulzbot.com/filament/.

The tube I cut is one inch long with a bevel at the top. It could be a little longer to keep the top closer to the hobbed bolt.

That’s really interesting nopick. Do you swap it in and out whenever you want to use the 1.75 filament? The method is loosely like the flexystruder however, the ptfe tubing isn’t intended to be removed.

I just ended up building my own toolhead by buying the parts from i-t-w.com as they sell the hexagon hotend with an actual 1.75 heat sink tube with heat cartridge and thermister for $40. I like putting stuff together so this made sense for me. You definitely have to buy some other parts to go along with it but they sell that as well. In the end, I think you can get all the parts for between $80-$100.

I know, i know. I’m a Lulzbot fanboy and a toolhead glutton. But I built every one myself over time for a fraction of the cost. In fact, my Taz is an upgraded Taz4 that I wouldn’t part with for anything. It has upgraded 12mm horizontal bars, upgraded PEI bed, Custom box and 4 toolheads. (Dual extruder v2, flexistruder, and a 1.75 and 3mm V2 toolhead.

Did you switch to hardened rods and lmu12 metal bearings? Just read your thread about your taz 4… and wondering if maybe the upgrade is worth it

OP: try recalibrating your esteps. Follow the lulzbot guide except for the extrusion speed. Reduce it to 40. at 100 it’s possible to count skipped steps from the back pressure created by the fast extruding. 40 is closer to what your print puts out during printing. Found this worked for me on the same toolhead. My esteps from the factory were a little high.

I stuck with the Igus bearings (new set). I know many don’t like but I still feel they are a superior bearing when all of the tolerances are right. They require no maintenance and are virtually silent (relative to the rest of the printer). I got the rods from i-t-w.com when the 6 first came out. They had a bunch of 2nd X-axis assemblies so I grabbed one just for the rods. Definitely a good upgrade for me as my dual extruder was weighing down the original rods.