TAZ Workhorse PLA jams almost every print

I usually print with PETG, but I have been trying to run a PLA print this last week. Almost every time the print climbs to 2cm high, the filament jams in the head. I have to tape off the fan and crank the temp to 250 to free it.

I have tried printing as low as 195, but then my prints aren’t so great. And I’ve had to unclog the head about 4X.

Any ideas what to do here?

I would try doing a cold pull, possibly with some cleaning filament, to make sure that there isn’t any other remnants causing the clogs. I’d then want to make sure the filament isn’t too wet by drying it out, and make sure it isn’t too old. PLA should be pretty easy to work with, definitely easier than PETG in my experience. It also requires a little bit more squish, so I run a little higher z offset and a slightly wider first layer extrusion for PLA vs. PETG.

Classic symptoms of heat creep. Good article here: How to Fix Heat Creep (3D Printer): Tips & Tricks | All3DP
Assuming your fan is already running at 100%, and it and the heat sink are clean, the simplest solution is #3, print faster.

I’ve been trying all day. This is what I am seeing…

(I ordered cleaning filament, but it won’t be here for a couple days)

I’ve tried up to 60mm/s. I’ll take a close look at that article though, thanks.

I believe I pushed it faster when I was printing face shields. If you’re interested, I can look at my Cura profile late tomorrow.

Our Workhorse doesn’t do PLA well. Most of our problem was a bit of PLA jamming in the heatbreak when changing back to a higher temp. filament. In hindsight, that was probably due to heat creep, too. Maybe the Workhorse heartbreak fan is underpowered or otherwise inefficient.

Maybe drop the bed temperature to 0. This should reduce the fan’s intake air temperature, giving you more margin. (You may have to use PVA to stick the print.)

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I print PLA on the Workhorse (using the factory HE 0.5mm head) at 230°C. So it may be that your temps are too low.

230°C sounds high for PLA … but keep in mind you are (a) using 2.85 (3mm) filament and not 1.75 and (b) using a hardened steel nozzle that doesn’t transfer heat as efficiently as a brass nozzle.

Ultimately… each time I use a new filament that I haven’t used before, I print a “Temperature Tower”.

Such as: Smart compact temperature calibration tower by gaaZolee - Thingiverse

You can search Thingiverse for ‘Temperature tower’ and get lots of variations on this. Each section of the model would be printed at a different temperature … and you inspect the quality of each section to decide which one looks best.

It takes a bit of setup. In Cura you set the print temperature based on the temperature of the base layer. Then use: Extensions → Post Processing → Modify G-Code. This opens a sub-window. click ‘Add a script’ and use ‘Tweak at Z or Layer’. Pick either the height (in millimeters) or the layer number where it should change temps. Then click “Tweak Print Speed” and set the new temp.

That changes the temp just once when it reaches that layer.

Then repeat… do another “Add a Script” and add the same script again (Tweak at Z or Layer) and set the layer number and the next temperature change.

And repeat until done.

Run the job through the printer and watch the quality as it goes. The models include features like bridging, overhangs, etc. and often include a feature that you can use to test for strength.

There are loads of variations on the temperature tower (and they come with different temperature layers so if you’re using a material that needs a hotter or cooler temperature range, etc. ) but it’s the best way to help you dial in the printer to the optimal temp for the filament you are using.

Keep in mind two different vendors that make PLA will not necessarily have the same ideal temp. I’ve even seen differences based on changing the color of the PLA from the same vendor. Basically they change the additives in the PLA and that changes the characteristics of how it behaves.

It’s all part of the fun.

I had a lot of problems with PLA. For years! Installed an air conditioner / heat pump… helped a lot! But the Pro PLA was too hard and brittle and jamed a lot or broke. Switched to ColorFab PLA/PHA which is softer. Good results so far.

Thank you all for your suggestions.

  1. I have been using polymaker PLA. I am just gonna give up on PLA for now. Nothing I do seems to work.

  2. I have ordered a replacement 40mm 5v fan. I’ll see if there’s more flow on that one.

  3. I am considering monitoring the cooler with a thermocouple. May or may not do this.

  4. Unfortunately, this seems to have messed up my head for PETG too. I have been clogging this now, and can’t seem to get the head cleaned out, even though I was able to run 2 sticks of cleaning material through it. I’ll keep trying.

Just a thought, pending more evidence, but if your PETG is jamming in the same way as your PLA, maybe it was never the PLA.

I think I may have followed poor advice and ran petg too hot through it too. Between both of those materials jamming things, the feeder may have clogged up.

I ran cleaning filament at several Temps all the way up to 275 and that seems to have enabled petg pretty solidly.

Still have some retraction strings, but not bad at the moment.