Mintemp Error and Breaking Heatbed Thermistor  

RE: Mintemp Error and Breaking Heatbed Thermistor

I wanted to write my experience with broken thermistor bed cable, but I just saw here that it's not so original! 😀 

My break occurred after some printing of ASA, so I suspect that the higher bed temperature was the the straw that broke the camel's back.

I was thinking about replacing the cable with a much more flexible silicone insulated version, and I see that it's neither a so bad idea, nor so original.

I thought of other minor improvements here:

1. The heatshrinking tube used to cover the joint between thermistor leads and cable is done with poliofelyn, a material cabable of withstaining 125 °C. As I'm on the job, I feel safer in the long run using something made of PDVF or silicone, that are capable to staying for undefinetly long periods at 175 °C and 200 °C respectively.
2. I don't get why insulated thermal paste is not used to improve the heat transfer between bed and thermistore, isn't better to apply it?
   Of course being absolutely sure that it's a not conductive version.

Thanks for the advice on power bed cable, while on the job I'll replace also them!

RE: Mintemp Error and Breaking Heatbed Thermistor

ive got one printer that does this on some prints.  Generally at the same height/spot on & above the bed.  I cant repro the issue without running a print.

super super frustrating.

RE: Mintemp Error and Breaking Heatbed Thermistor

I wrote to Prusa and got very soon a new thermistor for free, as my printer is just few months old.

In the meanwhile I ordered on Aliexpress what I need to build a more reliable version next time it happens, as described above.

I'm replacing also power cables for the bed with flexible and heat resistant silicone insulated version, to be on a safer side.

What I really find frustating is having the MMU2s to work as expected 😉 , this at the end for me was surely annoying, but just a minor issue, easily solvable.

RE: Mintemp Error and Breaking Heatbed Thermistor

@joantabb

Hey - so ive been trying to find the time to manage the issue im having on this one printer of mine - and well... i finally got it on video!

Note that during PRINTING i get "mintemp bed" and am totally unable to repro this outside of a print but i was able to get this video...

the question is - what do i need to replace.

RE: Mintemp Error and Breaking Heatbed Thermistor

I tried to edit the original post but im still a forum noob...

RE: Mintemp Error and Breaking Heatbed Thermistor

I think this cable and the nozzle themristor wires are the most common broken parts on the Prusa.  I treat them as expendable.  

RE: Mintemp Error and Breaking Heatbed Thermistor

@cwbullet

should last more than a month... i have originals running on other printers.

RE: Mintemp Error and Breaking Heatbed Thermistor

@benjamin-5

It depends on the stress you put on them.  I broke my first one in abotu 2-3 months.  I did not take the flex in wiring as it hit the back of my enclosure.