Taz Workhorse fails to maintain nozzle temp during printing

How much fluctuation is there supposed to be on the print nozzle during printing? I haven’t always paid attention, but recently we’ve noticed that after prolonged periods of printing the printer says the nozzle is only 220 degrees instead of 230 (We’re printing Polylite PLA) and it never seems to reach 230 or even 228. It seems to run between 218 and 224. It starts printing at 230 and then the temperature just falls off.

We’ve had some unusual jams occur and are thinking this temperature drop could be the reason. The jams occurred in most prints around the 1 hour mark. Previously we’ve been able to do 24 hour+ prints.

230°C is a bit high for PLA.

I am guessing the fan is kicking on and causing the temperature to drop.

I would suggest using the preconfigured PolyLite PLA profile in Cura LE.
Otherwise, you would want to lower your fan speed and see if that resolves your issue.

Thanks for the suggestion, but the default Polylite PLA profile for the workhorse is 230 b/c of it’s hardened steel nozzle.

I also am wondering if the fan is over cooling, but am curious as to why it didn’t seem to be an issue before. My other thought is that maybe it is the heater block failing.

Does your Workhorse actually have a hardened nozzle? Production on the Workhorse was switched to the standard nozzle some time ago because of the temperature issues the hardened nozzle causes.

Everything included claims its the HE toolhead… The nozzle looks like it’s hardened steel to us and our the Workhorse was purchased in early 2020.

Sounds like you do have an HE then. Just wanted to be sure you knew what you had.

One thing you might try is a PID tune on the extruder. Use the console in Cura to enter the gcode to do the PID Autotune and you might get more stable temperatures. It’s something like “M303 E0 C8 S230” to tune extruder 0 to 230 degrees for 8 cycles (more cycles gets a better result). Then use M301 command to set the PID values to the numbers that came out of the autotune results, and an M500 to save the changes.

If you aren’t sure about PID, here’s some helpful steps / tutorial


Thanks I had been reading about PID tuning and wondering if this is what was needed. I’ll give it a try.

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The only downside I see is that this will change back anytime you change print heads, since the PID values are part of the firmware.

There is normally a printer profile for each toolhead so you can add the M301 command to the start gcode (which is what I have done).

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So I tried PID tuning with the 8 cycles and entered the numbers. Saved it, but still get this.
workhorse temperature

Any ideas? I tried lowering fan speed to a max of 75% and still had this issue.

I’ve had the same issue on our Workhorse with the HE purchased around the same time. Only thing I’ve found to completely resolve the issue is turning down the part cooling to 50% or less. I am ordering some silicone socks for the hotend to block the air coming from the cooling fan and insulate the heat block. That would be my best suggestion, only other thing would be to print slower. If you are printing at large layer heights and/or at a relatively fast speed, it may be pushing more material than the heat block can melt.

Thanks we have been using the Fastest print setting a lot more often now than we ever used to. I’ll try reducing the fan to 50% and see what happens. Also please let me know if those silicone socks work for you.