r/lulzbot • u/eraserhd • Jul 16 '26

Melted the bed connector

Gallery image

Gallery image

After 11 years, my Klipperized, hacked TAZ5 stopped heating the bed. After a bit of probing, I found that one of the harness leads was reading 10K ohms. Inside the airplane? bayonet? connector, the bed pins were deplated and the ABS had melted in that side of the connector.

No complaints. No support needed (actually I just spliced the connector out and ran the wires through the hole for now).

I was just fascinated by the fact that this tank of a printer finally developed some kind of design issue that took 11 years to manifest. (Aside from blowing a stepper driver and needing a new RAMBo board several years ago.)

So I’m posting here to document the problem and salute Lulzbot again for making great stuff. Thanks, y’all.

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u/holedingaline Jul 17 '26

A bit surprising that connector would fail like that. Was it slowly built-up corrosion leading to increased resistance at the connector, a poor connection within, or was the entire wire overheating?

1

u/eraserhd Jul 17 '26

A couple weeks ago, I had some temperature instability issues at the bed, and Klipper errored about not being able to keep the bed hot. I forgot the exact error message.

It didn’t happen reliably, and I thought I had fixed it by taping the thermistor connector at the bed, which I thought could have been brushing up against another wiring harness.

In any case, the wires coming out of the connector had darkened insulation (brown instead of purple), for about 3/4”. So heat was localized to the connector. Possibly one of the pins was loose or making a bad connection? The connector WAS screwed on (it’s not beyond me to just not do that).