3D Printers, Makers, DIY hacks, solutions and post printing tools

Created by Emil Pop on 13 April, 2018

Printing with PLA, no socks, no problem.

Printing with ABS, no socks, sometimes boghery clogs over the nozzle and it sticks somewhere on the print, nozzle drags over, nozzle trips over, nozzle gets stuck a few seconds while the stepper motor keeps going as it skips a few steps on the belt... layer shift.

Printing with PETG... this beast needs higher temperatures, the bogs are more than ABS, gotta clean the nozzle often or ignore the bogs hoping no layer shift occurs, you know, don't focus on the bogus.

And all of a sudden thermal runaway is triggered.
So what is thermal runaway?
It is when the temperature goes higher or lower than set way too steep.

(does anybody knows who triggered my font on big here and how to bring it down?)

OK twice on enter and went down, but not what it is done, this platform needs improvement.

so thermal runaway is not mintemp (that would be when your sensor reads below the minimum threshold, which is either because is too cold in the room (rarely) or a cable is cut or unplugged or the sensor is bust) nor is it maxtemp, when it runs over the maximum set as safe in the Configuration.h file.

It is when the hysteresis is not respected. What is hysteresis, well apart of mintemp that usually is 5Celsius and maxtemp that is a "no go over" and for the bed could be 150Celsius or up to 300 for PEEK ready printers while for the nozzle usually is 270Celsius or up to 500Celsius for PEEK ready printers, you have another range, and that range is set around your actual printing settings, say you go PLA, so you print it hot, 230 Celsius, your hysteresis is max 232 Celsius and minim 227Celsius within a reading of "n" seconds given as safe. Usually N is 2 seconds minim and 20 seconds maximum or similar.

What happens if my temperature goes too high in too short time? Or too low? Runaway temperature kicks in and kills the print.

Apart from bad configurations in the safety lines in configurations.h and configurations.adv.h there can be some mechanical causes why the sensors read and send that data.

If there is an air draft from an open window suddenly cooling your bed (large surface, easy to cool, hard to heat) bingo... thermal runaway _BED.

If the heater of your nozzle cannot fight an air draft maybe coming from a fan that points wrong... you got it, thermal runaway _ H0. (that stands for heater number 0, your nozzle, if you have more than one, the next will be H1)

So you need to go dentist mode here, fully knowing that the patient suffers no pain.

I tried silicone socks over my hot ends. It sucks. They are not as sturdy gripping to the block as they should, more, with high temperature they get loose, peel off, get lost on the bed... thermal runaway _ H0 again.

Hence if the issue is mechanical, I went mechanical. Tied them up. Was thinking of the zip ties, but when the head is hot, they give in, no good.

And I went for a classic, took a bit of cable, some 10 centimeters, peeled off the plastic and got in my hand thin copper wires. Lots. Pure gold, trust me.

And tied them up with copper wire to prevent them from falling again.

May God have mercy on my not so modern soul.