XL hotend — Broken thermistor
As far as hardware is concerned, I've been pretty happy with my XL. The print quality is great, and with a 0.8 mm nozzle feels better than my Mk3S or Minis. And of course, no longer having to calibrate live Z is awesome. Some firmware issues, mostly around connectivity and PrusaConnect but nothing that's a showstopper.
I've been going back and forth between the 0.6 and the 0.8 mm nozzle for different models. The whole process of swapping nozzles is anything but quick and requires removal of the complete hotend. My not-so-great experience of trying to use the nozzle adaptor with my Tungsten Carbide nozzles I wrote about elsewhere in this forum. So standard Prusa nozzles it has been.
Today, after about 10 nozzle swaps, I'm getting a thermal runaway warning. Checked the wires, and yes, the thermistor wire looks a bit frayed where it enters the heater block. Wouldn't be the end of the world if I could actually order XL spare thermistors or complete hotend off the Prusa store, but of course, no dice ☹️ No spares available at all.
Prusa support on the chat confirmed it's a thermistor issue but have to get back to me by email. I hope they'll find an off-channel way for me to buy a thermistor or hotend or my XL is just a nice-looking brick.
I don't know, the whole hotend design feels like a huge step back from the Dragon hotends I've been using on all my Mk3s and Minis. I get it, the hotend needs to support the new sensor that obsoletes live z calibration, but this pulling cables out from behind the print fan to get the hotend out and then pushing them back in feels like a recipe for wearing out the thermistor cables in no time.
Formerly known on this forum as @fuchsr -- until all hell broke loose with the forum software...
RE: XL hotend — Broken thermistor
I have found thermistors are prone to failure more often than I like. I am concerned about thermistor supply for the MK4 Nextruder also. I can't find Nextruder thermistors listed in the Prusa Spare parts or in 3rd party suppliers. Let us know what you find out.
It may not help now that the cable is broken, but I am considering using something like JB Weld High Temp Silicone around the thermistor wires near the hot end to re-enforce the wires. I looked at liquid tape products, but the operating temperature is too low on them.
That is what we get for being on the leading edge. In front of the windshield. All the bugs in the face...
RE: XL hotend — Broken thermistor
Thermistors for the XL are available. They list it as a replacement.
RE: XL hotend — Broken thermistor
Finally back in business. Bought a boatload of thermistors and heater elements. Alas, the heater blocks are still "on backorder".
Replacing the thermistor showed me another flaw of the new hotend. In the standard E3D v6 hotends there's a hole on both sides so you can use an Allen wrench to push the thermistor out. In the new hotend, you have to pull the thermistor out and, not surprisingly, the cable came off. As it was a broken thermistor anyway, no big deal, yet I'm not enamored with this solution.
I'm now swapping nozzles by leaving the cables attached, simply dropping the hotend a bit, and using the Prusa universal wrench and a torque wrench to swap the nozzle in situ. Requires less manipulations of the wires so hopefully they'll last longer.
Formerly known on this forum as @fuchsr -- until all hell broke loose with the forum software...
RE:
thermistor of the XL, super sensitive, broke two in a short time, frustrating