How to fix the thermistor cable?  

RE: How to fix the thermistor cable?

I wouldnt want to use most tapes that near to the heatblock. Kapton tape may be ok! but not PVC electricians tape, heatshrink sleeve would be my choice...
I believe the electrical  joint should be crimped, it may be possible to remove the old heat shrink, to expose the crimp, re insert the wire and crimp harder....

soldering was old school. might tide you over while you get anew thermistor and cable.
probably won't like exotic filaments...

But if you are going for exotic filaments, now may be the time for a pt100 thermocouple, amplifier and firmware revisions.

regards Joan

RE: How to fix the thermistor cable?

The thermistor wire might have been crimped or soldered.  It may even have been spot welded.  But you can remove all the old heat shrink, throw some new shrink on, pushed back away for the connection, then try recrimping (per Joan's suggestion) or find an electronics parts store (where is Radio Shack when you need them) and buy a small crimp style connector pin and insert both ends into it and crimp.  You could try soldering, but if the thermistor end is steel and the plating is gone, oxidized from frit processing into the glass, solder may not wet properly.  Twisting the wires is probably bad for the health of the thermistor end... but you don't have a lot to lose at this point.

I'd vote to open my wallet, and try to somehow recrimp while waiting for DHL.

RE: How to fix the thermistor cable?

Thanks for the tip, it wasn't hard to remove the sleeve, and after cutting the shrunk ends I can even put it back on so it can be heat shrunk again (the middle part is big enough to cover entire exposed wire). But no crimping tool. Would a LAN Cable crimping tool work? IT guys at work probably have one of those I could borrow.

> But if you are going for exotic filaments, now may be the time for a pt100 thermocouple, amplifier and firmware revisions

No way, this is my first printer. I'm not upgrading anything until everything has been working fine for while 🙂

RE: How to fix the thermistor cable?

Seriously, any crimp connection requires a specific tool and die to ensure the proper pressure is applied based on wire size and compressibility/deformation qualities.  In this case, needle nose pliers will work well enough. Get the wires in place, and squeeze. If there is room, squeeze in two places.  Tug lightly on the wires, they should stay together - if they slip loose under a gentle pull, try again but squeeze harder.  

ps: No - a LAN tool uses a different style crimp, and will not help. 

RE: How to fix the thermistor cable?

One of these might...

RE: How to fix the thermistor cable?

Posted by: Tim

One of these might...

if you can find enough slack without destroying the connections to the thermistor lol... 

is it possible to extract the thermistor while you try crimping to prevent further damage?
the thermistor is held in position by a tiny grub screw and possibly molten filament... be gentle

if you are buying spares, especially from Prusa, consider getting two hot end thermistors, a heater and a heatbed thermistor, to make best use of the delivery costs .,then after doing the repairs, you should have a set of spares for next time!
(oddly, having spares on hand, seems to delay, the next problem... )

Joan