Thermistor on hotend (solder on a new one)
question; why exactly do we need to buy these custom e3d or prusa thermistors (on backorder). Why can’t we buy the e3d unit and solder on the two leads to the existing connections. Since it is a thermistor, there should be no polarity. So other than having to solder on two leads, why aren’t others doing or have done this?
Is there a reason or risk not to?
how often do you guys change your hotend blocks?
RE: Thermistor on hotend (solder on a new one)
Is this a theoretical question or are you solving a problem?
I agree that soldering one in is probably OK, just stay far enough from the heatblock so it won't weaken or melt the solder. Since all the I3s take the same thermistor, I don't see why one from E3d won't work.
As for changing the heatblock, in 5 years of printing I never have. The only reason I could see for doing so is if it's so caked up with plastic that I can't get at the grub screws to replace either the thermistor or the heater cartridge.
Cheers
-Bob
Prusa I3 Mk2 kit upgraded to Mk2.5s, Ender3 with many mods, Prusa Mini kit with Bondtech heat break, Prusa I3 Mk3s+ kit
RE:
Is this a theoretical question or are you solving a problem?
I agree that soldering one in is probably OK, just stay far enough from the heatblock so it won't weaken or melt the solder. Since all the I3s take the same thermistor, I don't see why one from E3d won't work.
As for changing the heatblock, in 5 years of printing I never have. The only reason I could see for doing so is if it's so caked up with plastic that I can't get at the grub screws to replace either the thermistor or the heater cartridge.
Cheers
-Bob
I have changed the heatblock for exactly this reason, it was caked up with burnt plastic and the thermistor and heater could not be removed. I rebuilt the hot end with Prusa parts though. Thermistors are not all the same. They have different calibrations. Maybe the one from E3d is the same. I don't know. I have added wire to thermistors and there is no issue with calibration. The added wire resistance is small compared to the thermistor resistance. Solder does create a point that is likely to crack if flexed. It would have to be in a location that does not flex.
At least to the US, if you buy two rolls of filament from Prusa, you can add small parts to the order and the shipping is pretty reasonable. The total cost is not that different from buying other high end filament plus parts.
Regards,
Mark
RE: Thermistor on hotend (solder on a new one)
I am only asking because the original prusa part is backordered. I did order one from third parties. We will see. I did order the hotend and the nozzles from prusa and paid for dhl shipping. The cost is not the issue. It is the availability of the part
I was able to get the original heating element out by removing the hex screw and then prying open the hotend with a flat end screwdriver at the gap. Heater came out easily. Original thermistor still stuck and I am chipping away at it
original hotend had caked on filament. Dremel it all away but I will just replace it. Replacing the heatbreak at the same time. Probably can be reused. But I low grit sanded it and now the hotend has a ridged surface, which may be good for filament to attach to, will need high grit sandpaper to bring it back to a smooth finish.
I wrote e3d. They mention the mini is a special thermistor , and regular v6 will not work. Just an fyi.
RE: Thermistor on hotend (solder on a new one)
I am only asking because the original prusa part is backordered. I did order one from third parties. We will see. I did order the hotend and the nozzles from prusa and paid for dhl shipping. The cost is not the issue. It is the availability of the part
I was able to get the original heating element out by removing the hex screw and then prying open the hotend with a flat end screwdriver at the gap. Heater came out easily. Original thermistor still stuck and I am chipping away at it
original hotend had caked on filament. Dremel it all away but I will just replace it. Replacing the heatbreak at the same time. Probably can be reused. But I low grit sanded it and now the hotend has a ridged surface, which may be good for filament to attach to, will need high grit sandpaper to bring it back to a smooth finish.
I wrote e3d. They mention the mini is a special thermistor , and regular v6 will not work. Just an fyi.
The Mini has longer wires I think. At least the heater has longer wires.
Regards,
Mark