When in doubt, solder it out.
Not to get too pedantic, but a (properly!) crimped joint is actually better than a soldered, or even a crimped AND soldered joint. Crimp connectors are carefully designed to allow just enough movement to prevent strand breakage due to fatigue; this is part of the "strain relief" design that every connector needs. Soldered connections constrain the wire too much, it will flex only at one point and will eventually break just where the strand emerges from the solder. Additionally, crimping a connector causes several small cold welded connections, and the resistance of the connection is actually lower than a soldered joint. NASA and the military do not allow soldering crimp connectors.
Realistically, we aren't building for NASA or even making our own airplanes, so soldering them is probably perfectly adequate. Just be aware that a quality crimping tool might be a good investment, and might prevent a breakdown on the road someday.
Just throwing some experience in..
While this is 100% true and any aircraft mechanic, or automotive engineer will agree.. the problem is that we are not using carefully designed quality crimp connectors. They will never fold over into the wire and compact it until its almost fused into a single part.
There are 2 connections on every wire connector.
Electrical connection
Mechanical connection.
Electrical connection:
If you were to measure the electrical connection carefully before and after soldering, you would see an improvement. Most of the time it doesnt matter, but when you're talking 40+ amps, its a measurable drop. So soldering does help this... however it is NOT a replacement or even a helper for the mechanical connection.
Mechanical connection:
A proper mechanical connection means you can pull the wire and it will break before it comes out. The power of the crimp should exceed the tensile strength of the copper wire. If its not, you're doing it wrong.
That said, the copper wire will break if you solder it, unless there is strain relief.
For most DIY home connectors there is strain relief, in the form of two crimps. if you only solder the first crimp, the one closest to the connector, the second can act as a strain relief. You will never see vibration/flex induced failure as long as you dont solder into or past the 2nd crimp.
but what if there are no second crimps? then you add an additional strain relief. a simple example would be slipping a piece of flexible plastic tubing over the wire and crimp and heatshrinking it in place. If the crimp is on a connector pin, then place the strain relief on all the wires after the connector, and include the connector in the heatshrink.
None of this is hard, but it does require some thought. I have been making custom electrical devices for 13+ years now for other forum/hobbists, and I've never had a wire failure from vibration... and most of my devices and harnesses are on sportsbikes and drag cars... things with large vibration and shock hits... and street cars that see a good bit of miles.
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Topic: <$20 Y-cable build (Read 3319 times)