Did the wire fall out of the crimped terminal? I've already had one of my thick 6-ga wires fail in this way (did not pass the tug test during my pre-airworthiness condition inspection). Now I'm doubting all my crimps. Used one of those crimp tools you whack with a hammer. Wish there was a better way to secure large important wires to ring terminals.
The hammer type are very prone to not getting a solid crimp. The best low cost options are one of these from Amazon.
https://www.amazon.com/IWISS-Termin...ocphy=1013950&hvtargid=pla-370713145091&psc=1
https://www.amazon.com/Hydraulic-Cr...la-894165565634&ref=&adgrpid=90730998421&th=1
Any reason we can't crimp then solder the connectors?
Did the wire fall out of the crimped terminal? I've already had one of my thick 6-ga wires fail in this way (did not pass the tug test during my pre-airworthiness condition inspection). Now I'm doubting all my crimps. Used one of those crimp tools you whack with a hammer. Wish there was a better way to secure large important wires to ring terminals.
I have been told by people smarter than me that solder imposes a level of brittleness to a connection that increases its likelihood of fracturing under vibration stress.
Wire/cable for aircraft/cars/other moving units, are made up of multiple strands to allow for flexing of that wire: the strands move on each other not allowing stress to build up on a specific area. This is why we do NOT use solid wire/cable on aircraft. Now: solder that wire and you have essentially turned it into a solid piece and the strands can no longer move on each other. The stress will be concentrated where the solder ends. Stranded wire can move slightly even in a terminal.
If you have solid wire ANYwhere in your airplane, go rip it out.....
Ken
Glad to see that you only had a burnt wire, it could have turned out much worse.
Quick question- did you have a circuit breaker or inline ANL fuse on the B lead,For this exact scenario? If so it it work? Or was the wire just arching across the crack in the terminal fitting?
Regards
Peter
Did the wire fall out of the crimped terminal? I've already had one of my thick 6-ga wires fail in this way (did not pass the tug test during my pre-airworthiness condition inspection). Now I'm doubting all my crimps. Used one of those crimp tools you whack with a hammer. Wish there was a better way to secure large important wires to ring terminals.
And yes, a proper crimping tool is required, IMO. Beating a crimp with a hammer seems kind of neanderthalish, to me.
OK, so do not "beat a crimp (tool) with a hammer". Instead, put it in a vice and crank it down in a controlled manner, to the required crimp height. Worked for me on all the large crimps, with tefzel wire. None of them have misbehaved in 1000+ hrs.
The other important part of this, whatever wire is used, is to properly support the wire all the way out as close as possible to the termination point. This is not a place to scrimp on mounting hardware (ie: do not use zip ties to attach to some engine/engine mount hard point). Use Adel clamps to a rigid part of the engine, engine mount, etc. Yes, they can be a PITA to install (although there are several well documented methods to make installation easier). If the fat wires (or any wire, really) can not move, they can not fatigue, and can not break. And if ya don't want the wire to move, SECURE IT to a hard point.
Take a look under the hood of any modern car. Wire bundles are secured to something. Nothing is put in place, just hoping it will stay there.
Here are photos of my wire runs to the alternator and the starter:
View attachment 27485
View attachment 27486
View attachment 27487
View attachment 27488
These are lovely wire runs and supports and all, BUT...the problem here is not, I think, with the wire run. It's with the *bend* in the wire to take it to the terminal post. The large, stiff wire wants to unbend into a straight run, thus putting stress on the crimped connecter, ultimately leading to a break (or some number of strands break, which then leads to heating in the remaining ones, etc.). At least, that's my guess, based on what I've seen on friends' RVs with the same wires and runs.
The wire did not come out of the crimped terminal.
Any reason we can't crimp then solder the connectors?
Does anyone make a 90 degree lug adapter suitable for large starter and alternator wires/cables?
George: Here's one I found within a few seconds. I know that there are others out there, including copper ones.
https://www.digikey.com/en/products...MIsJjn8LSO_gIVShZMCh0WowcbEAYYBiABEgJ61PD_BwE