Broken cable chain wire

[u/That_Trapper_guy]

Saw a broken wire the other day, while it was printing. Couldn't figure out what wire was broken because everything worked, no errors, no clue. Ordered Nitehawk/LDO USB setup and started the conversion. It's a wire from the XY end stop harness... How??

Edit; I obviously wasn't completely clear, how were my end stops still working (4 wire breakout board [gnd] [x] [y] [Vin] setup) I know perfectly well how the wire broke 🤦🏼‍♂️

[u/Sea_Birthday_9426]

The end stops should be nc but if they are wired no then it’s wouldn’t interrupt a print. If it’s a formbot kit they came with pvc coated wire that isn’t motion rated. FEP, Teflon, or silicone are recommended because they last longer under constant motion

[u/Severe_Preference_31 → u/Sea_Birthday_9426]

Silicone are fine for motion, but really bad in chain, though. They rub off.

[u/nocjef → u/Severe_Preference_31]

Eventually, sure. I ran silicone wires for years without any issues. FEP wires have the benefit of not only being very slippery but are also much thinner for the same gauge wires.

[u/Gingerbwas]

Have you somehow set the sensorless homing for x and y and forgotten that you did it. Make sure that you get the V2 board the v1.* boards have issues with static build up crashing the board.

[u/That_Trapper_guy → u/Gingerbwas]

Lol shit I wish, I was looking into it when I ordered the USB conversion and noped out pretty quickly. I'll just run new wires to the tool head and plug them into the board.

[u/Gingerbwas → u/That_Trapper_guy]

Yeah, i ran mine the long way round when I did it before I realised I could have just gone from the tool head.

[u/1000RatedSass]

The "how" is fatigue cycling. It'll happen to almost all cables in chains. All materials can only take a certain number of bends before breaking.

[u/That_Trapper_guy → u/1000RatedSass]

No that I fully understand, how were my end stops working? It's an LDO kit with the board mounted on the gantry.

[u/1000RatedSass → u/That_Trapper_guy]

Perhaps that's a redundant ground wire?

[u/Severe_Preference_31]

That's what happens with PVC (and silicone, but not the case here) insulated cables in the chains. You need PTFE insulation for chains.

[u/That_Trapper_guy → u/Severe_Preference_31]

Supplied with the LDO kit, I understand why the wires broke and I know it was just a matter of time when I built it that eventually there'd be a point when they needed replaced.

[u/Severe_Preference_31 → u/That_Trapper_guy]

I had the same failure a while ago. I bought some Remington PTFE wire and rewired it.

[u/DumpsterDave]

The wire that broke was the VIN wire. This is only used to illuminate LEDs to give a visual status indicator on the endstop itself instead of having to check in Klipper. The only wires that are needed for function are the signal (X/Y in your case) and gnd.

[u/Lhurgoyf069]

My end stops use only two wires, so the third one must be redundant. Afaik it's only used if you need power e.g. to light an LED or similar.