How to Remove Material with Broken Temp Sensor?

[Tafelspitz 5]

Hi all,

 

I'm new to the forum but need some help. I got an UM2+ with a broken temp sensor. I already have a new temp sensor at hand and try to follow the steps in the online manual to replace the sensor.

So far so good, the only problem is that my PLA is still in the printer. However, to replace the temp sensor, I apparently need to remove the PLA from the nozzle. But how am I supposed to remove the PLA with the broken sensor which won't allow me to heat the hot end in the first place? Seems to be some kind of catch 22 to me.

I wonder why the manual doesn't cover this problem.

Anyway, any help would be greatly appreciated!

 

Dom

Edited January 21, 2018 by Tafelspitz

[gr5 2,230]

This is a good question.  There are lots of solutions.  You only need to get the PLA up to about 100C to get it out.

 

The option I would go with is to connect up the new temp sensor to the board under the printer and then heat up the block.  There's a chance you can get it up to 100C before the firmware realizes that something is wrong - it will heat for about 30 seconds before realizing the heater is not heating the sensor.  That should be long enough to get it to 100C.  Put a drop of water on the block to be sure.  Maybe power cycle the printer quickly when it fails (heater error) and do it one more time - that will give you 60 seconds of heating and that should be plenty hot.  In fact be careful not to over heat too much - hence the drop of water.  Anyway you'll also know it's hot enough when the filament pulls right out.

 

 

[Tafelspitz 5]

Brilliant. That did the trick. In fact just one heat cycle was already enough to get it out.

Thank you very much!

[Tafelspitz 5]

Whew, replacing the PT100 was more complicated that I've anticipated. Although I'm actually no stranger to screwdrivers and handywork, it took me almost 2 hours to get everything sorted. Getting the PT100 all the way through the braided sleeve was a tad frustrating and I had to give up about 10 cm before the print head. I eventually poked it through the sleeve and pulled it through, bypassing the last stretch of the sleeve. Definitely not something I want to do on a regular basis.

Obstacles aside, I'm now happily back in business and printing the calibration spacer as I type.

 

Thanks again for the help!