Thermistor cable rupture/break and changing wiring to the better
Hi guys
Yesterday I started printing the nice bird feeder which Yury posted here. Things were looking fine so far. But at a certain height (at about 110mm) I was worried about the cabling from the extruder part hanging down too far and may break away the supports or get in contact with the model. To give it a easy and quick fix I used a cord which should hold up the wiring a little. The cord was fixed on the cabling with a small loop and on the other side to the spool holder. There was very low tension on it and the wiring had an angle of max. 10° upwards from horizontal. So for a normal wiring this is really not an issue.
I went back to the couch because it looked fine. Shortly after I heard that one of the fans is oscillating. That does not make sense. Went back to the printer and watched what was happening. I then saw that the printer stopped extruding in some regions and that the extruder cooling fan (the 30mm fan) is oscillating in its speed. WHAT?!? Then I saw that the temperature of the hotend is oscilating as well. Conclusion: Expected thermistor cable break
I estimate that the printer was running about 50h until now. The wiring should hold much longer!
I didn't take it apart because it was already night time. But a thermistor cable rupture/break would be the only logical explanation. I think that the wires used are not specifically ment to bend or move all the time. That why I was looking out for some wires which are used in cable chains. They have certified and guaranteed bendings and are usually more flexible.
Due to the fact that I want to change the wiring anyway to the nice cable chain solution which Aaron posted here I'm thinking about rewiring all the wiring from the extruder assembly as well as the wiring from the heated bed with some cable chain certified cables.
Question:
Is there anything I have to take care about which I might miss to think about?
Does anybody have another/better suggestion?
Re: Thermistor cable rupture/break and changing wiring to the better
So no suggestions or warnings until now.
I will check what's required and give it a go then. 😎
Re: Thermistor cable rupture/break and changing wiring to the better
hmmm... i don't think that the cable broke because you've attached your little "hold-it-up cord".*
something in the wiring (or even the connector at the rambo) must have been pre-marred and messing around at the cable might have forced it to get loose completely. could have had happened during normal print as well, i guess.
*) by the way: did the same here: attached a chain of small rubber bands to the cable trunk and fixed it at the spool holder 😎 .
dem inscheniör is' nix zu schwör...
Re: Thermistor cable rupture/break and changing wiring to the better
I will check everything when I dismantle the cable harness comming from the extruder assembly. I will have to check the conductor cross-sections anyway to select the corresponding cable chain certified cables. 😉
Re: Thermistor cable rupture/break and changing wiring to the better
Having had to tie the cable bundle upwards does tend to indicate that your cable management is not ideal.
My cable bundle naturally rises upwards at all heights. Yours should too.
Peter
Please note: I do not have any affiliation with Prusa Research. Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage…
Re: Thermistor cable rupture/break and changing wiring to the better
If the fan is oscillating check out this thread to see if you are having the same issue. http://shop.prusa3d.com/forum/prusa-i3-kit-building-calibrating-first-print-main-f6/after-45-days-of-continous-printing-1st-maint-need-t3107.html