[engi_nerd]

I currently work as an aircraft telemetry and instrumentation engineer, and have also done similar engineering on rockets. So I spend a lot of time thinking about (and have been trained very thoroughly about) connections and how to do them.

> Hey, that's how you're supposed to use heatshrink! Wow, I've been doing it wrong for years.

Out of curiosity, how have you been doing it? The way shown in this manual is the standard way to do it in my world.

> Mildly surprised that they don't want crimped connections soldered

I'm confused as to why you would think about soldering a crimped connection. Properly crimped connections will stand up to a good deal more vibration (and are pretty much gas-tight, staving off corrosion) than soldered connections. Plus, crimping is quick and easy with the right tools. Maybe there are some niche applications where you'd do both. I've never seen it.

> Wow, had never heard of "connector saver" jumpers before. Sounds bananas

Totally not bananas when you look at the spec sheet for something like a D38999 series connector. Connector savers are a normal thing in the aerospace world. Most connectors are only rated for a few hundred mate/demate cycles (Usually 250 or 500). Every time you mate or de-mate a connector you run the risk of damaging a pin or socket. So the connector savers are sacrificial for when you test. They get mated to the real connections once at the beginning of your tests, and demated at the end. Then you give your real connections a thorough check at the physical level and hook them up.

[HeyLaughingBoy]

I'm confused as to why you would think about soldering a crimped connection

Because most crimped connections (at least in the hobbyist/DIY world) are crap. So after crimping, the only way they hold together is with solder.

There are no applications where this is better. Every connector manufacturer I know recommends against doing it. You can get away with doing it if you support the soldered end against vibration, but you should do that anyway.

It's really a training issue. People haven't been taught better and there is a lot of bad advice floating around hobbyist forums. I have only been using good crimping tools for the last few years since I started making a product with a 50-conductor harness. Until I spent $200 on a crimping tool and took the time to research how to make good crimps (Molex has an excellent document), I never realized how they were supposed to look. Now most of my tools are used, purchased at auctions of dead companies, but I have $400 crimping tools I paid pennies on the dollar for. Even so, I normally farm out crimping to a company that does it with automated machinery, better and faster than I can do by hand.

[asynchronous13]

Most of the crimpers I use are $1000+. I was totally shocked at the expense when I first switched from home hobby to professional work, but the quality of the crimps is simply incomparable. Very much worth it for reliability.

[HeyLaughingBoy]

I don't think I've seen a manual tool that was so expensive. Are you using some kind of pneumatic crimper? I thought of getting even better tools, but I found an outfit that will cut and strip wire to my spec. and crimp on any contacts I need, and they do it cheaper and faster than I can.

[engi_nerd]

No, that's about how much a good manual crimper costs. But man, the results you can get out of them are fantastic.

[engi_nerd]

Yeah, this is the difference between the hobbyist world and the aerospace world. As I've said before, that's where I spend my time...But I can understand why people don't have crimp tools and dies at home because just the die for a certain type of crimp connection can be several hundred dollars. That's just not doable for the vast majority of hobbyists.

Thanks for pointing this other side of the equation out.

[nialo]

I work with 1000-1200C resistance furnaces, and my understanding is that the internal connection between the heating element and the power leads is both crimped and welded. It is probably a niche application, and welding and soldering aren't quite the same, but it does happen.

[engi_nerd]

And this is one reason why I love HN, and why I threw in that caveat, because I knew someone would come up with a scenario where it's done. Thanks.

Like I said, I come from the aerospace world, where as another user here said, we solder as little as possible. Sure, components on PCBs are soldered (and even then, they are often covered with an inert, non conductive coating or RTV to fix them in place), but when it comes to wiring and connections, solder joints are asking for trouble when they get vibrated.