Hardware is HARD

I've had very bad luck with 'crimps' - esp when they are exposed to the weather, but even in higher-vibration environments. Wasted lots of time trying to track down problems related to crimps. The worst case was a relative who was into boats ... the connections WOULD show voltage or a ground with today's high-impedence meters. Ultimately had to build a LOW-impedence meter, with a big resistor inside, that pulled a LOAD of about two amps. THEN you could find the faults.

Solder correctly and put heat-shrink over it. You'll be fine.

Yep, it was VERY popular for prototypes back in the day - and for good reason.

I've also just seen plenty of cases where the successful proto just got all its wraps soldered for posterity. Had my hands on a whole LSI-11 kit computer done like that.

Vibration is the 'hidden threat' ... not always an obvious issue to eye or mind, but it'll GET you. Even pure copper wire will eventually develop stress cracks due to vibration. I did a lot of automotive/truck projects back in the day and we learned to strap-down *everything* to keep it from buzzing around.

Most 'computer' people these days are really most entirely 'software'. They can't see mechanical or noise or RF issues that crop up in the Real World. The 'techs' who DO may not be as good with software. It's a problem. There's a window of maybe 1960 to 1985 where 'programming' and 'design/construction' kinda went together. Not nearly as many now who cover one end to the other except maybe the "BattleBots" crowd.

No argument here (my background is systems design and programing on Mainframes, minicomputers and fault-tolerant systems.

The other gang that understand interactions between electronics and vibration are model flyers: radio control models, drones and, the most vibration of all, IC powered free flight competition models: a current F1C class model has a 2.5cc engine putting out around 1.3 HP at 30,000 rpm and carrying electronic flight timers and a GPS-based radio beacon as a retrieval aid. Free flight models regularly travel 2km or so in the course of a 3 minute flight, especially if the contest is being run on Sculthorpe, an ex-RAF/USAF base in Norfolk,UK. This area is known for its fresh sea breezes.

I still remember a very interesting one in the 1980s with a joystick for a Sinclair Spectrum. The box proudly proclaimed the use of gold plating in the internal connections. They used fully (i.e. not selectively) gold plated crimps onto stranded tinned copper wire. One of the joints, although completely mechanically sound, was not conducting electricity. Yes, that really was the interface between the crimp and the wire.

I ran solder in and it was fine.

There is a known, but unfortunately not widely known, problem in the interface between gold and tin.

The lesson boils down to:

2) If you're using gold plated connectors, use selectively gold plated crimps in them.

David

I did a lot of microcontroller-based projects back in the day. This was "end to end" design. You had to not only program, but implement the hardware - with attention to all the real-world annoyances, and there might be software tweaks required to HELP with those Real World issues. Actual electronics/soldering was involved.

Since that time, software/hardware have kind of become distinct specialties ... but that middle ... where it all has to come together ... seems to have been lost.

An actual hydrocarbon-fuel engine WILL create a lot of very buzzy vibration - which WILL take its toll on every connection. It's amazing how quickly some connections will fail - chips can even work their way out of conventional sockets.

And then, if an ignition system is involved, transient electrical noise ! :-)

(which is usually high-voltage/micro-amperage, which makes opto's esp useful)

DID have one ! :-)

Yep ... crimps SOUND great - until you hit the Real World.

Crimps are a cheap quick fix.

Material compatibility IS always important.

Gold MOSTLY works with everything but, by experience, not ALWAYS

Soldering IS a bigger pain in the ass, no question. But it's MUCH more sure. It'll last 20-50 YEARS under really crappy conditions.

My old old HOUSE is mostly SOLDERED electrical connections - not even sure how they DID that conveniently back in the day. However I'm NOT worried about any of those connections - mostly in the attic/ceiling - overheating like modern screw-terminal connections that oxidize or where the copper compresses and becomes loose.

A couple extra hours in 1950 meant 100+ years of reliability. When (likely soon) the house is destructed the ELECTRIC will still be 100%

Anyway ... BAD experiences with 'crimps' under a variety of conditions. Soldered is much more sure. Solder, add heat-shrink to spread out the mechanical stress and weatherproof ... electronic nirvana ! :-)

Sorry, I'm very old-school in this respect. I really design for 100 years safe service.

Yep. Some of those "old world" solutions can STILL be good solutions !

And, when everything's 100%, you can always solder the wire-wrap.

As said somewhere, one employer had a *kit* LSI-11 box. It had BASIC, but everything of use was writ in FORTRAN. They'd worked out all the wiring issues and soldered the wire-wrap. From there on it was just a software box. It's STILL around in a storage spot somewhere, I'll bet on it. And it'll still WORK - (assuming the 8" floppies can still be read). Oh, dual 8" Shugart floppy unit ... weighed about 75 POUNDS, BIG transformer :-)

High performance model engines have no ignition: they're either diesels (COMPRESSION IGNITION burning an oil/kerosene/ether mix) or gloplug ignition (battery heated plug with platinum coil to start, when running combustion keeps the plug hot and burning methanol/oil mix, sometimes with added nitromethane for more power.

You quickly learn how to protect in-model electronics and associated wiring from the engine's vibration - if you don't you'll have lots of more or less spectacular crashes. An F1C class model can climb vertically to around 120m with a 3 second engine run.

Yea - but those are MODELS. Compression/glow + fuel still means a lot of vibration. It's just not so important. Now in actual 18-wheelers, 737s, M1 tanks - it IS very important.

Soldered is THE standard. Kinda mush the strands together and solder and make sure you have some heat-shrink about 2X the width of the exposed copper for stress relief. If the env is "buzzy" then you have to strap down the wiring too.

I live in an old house. All the wiring was initially SOLDERED. Not sure HOW they used to do that efficiently. The connections where then either put in early twist cons and/or covered with the olde-tyme rubbery "friction tape" (which they STILL sell). The big wires are all industrial-qual early ROMEX with the fiberglas shield inside and mostly in metal conduit.

It's a house with a lot of WOOD - no drywall crap. I am NOT worried about what's in the attic or walls because the cons are SOLDERED. They'll be good for 200 years. No oxidation, no loosening probs associated with 'compression' connectors.

Anyway, as they say, you get what you pay for. Modern cons are "adequate" - but not for 25 or 50, much less 200, years. The wiring WILL oxidize or loosen - then get HOT. For real-world equipment soldered IS still best as well for reliability.

Recently replaced a plug socket. Put SOLDER over the ends of the wires and used the SCREW DOWN terminals rather than the "push in" ones. A little extra effort PAYS OFF longer term.

Just sayin' ... there's "to code" and then there's GOOD.

But best practice documents say using soldered/tinned wire in screw connectors is bad due to differing expansion rates of the brass fitting and solder. With enough sufficient thermal cycles the connection loosens causing bad connections.

Obviously the experts should have consulted with you.

Don't expect any problems with a microns-thin solder coating. The main goal there is to shield the copper from oxidation/corrosion. My environ IS a bit corrosive. House fires due to older connections is NOT unheard of. Breakers protect from overload, but cannot detect a degrading connection.

Now if you just glob LOTS of solder on there ...

There ARE some kinds of 'goop' that claim to protect the copper, but I'll stick with what I know is good. Some of that goop is hydrocarbon based - basically gasoline if it gets hot. The silicone-based ... I'd have to see some good studies as to HOW much that restricts current flow and whether it can degrade PVC insulation long-term.

They should have. I have lots of real-world experience with marine applications.

Sounds like a recipe for a fire. I've seen screw terminals on 3D-printer motherboards that were scorched after tinned wires had been put in them, and they only carried maybe 100-200W at 12-24V.

The proper way to connect stranded wire in a screw terminal is to crimp the wire in a ferrule or a fork or ring terminal (depending on the screw terminal type) and then attach it to the terminal. If your crimping tool isn't working reliably, either you're using it wrong or it's a crappy tool that should be replaced. (The slip-joint pliers in your tool bag aren't a proper crimping tool. Long-nose pliers aren't, either.)

Solid copper wire can be safely attached directly to screw terminals.

Never ever use screw terminals onto stranded wire that you've tinned. Solder suffers from creep, so the pressure slowly relaxes until the joint is loose. As stated above, a recipe for a fire.

David

True !

But be aware that electrical-quality copper ALSO 'creeps'.

Had a mystery power prob at my home a few years ago - it turned out to be that the old screw-down connections in the MAIN BREAKER had 'crept', loosened, over the years. The electrician I'd hired put on rubber gloves and re-tightened everything HOT. Good for another 20 years I suppose.

For awhile I was responsible for control panels in 20-50 horsepower industrial devices. Once most were 10+ years old I decided to test the old power connections. They were ALL getting loose - the copper had 'compressed'.

DO sometimes run into home sockets and such where the screw-down has a sort of bronze/brass PLATE under it. Put the wire under the plate. It creates spring-tension that'll greatly reduce the 'compression' issue.

Note that 'tinning' the stranded wires DOES seem to slow down the 'creep', if you 'tin' correctly (meaning JUST enough solder to solidify/bond, not big blobs). IMHO, house-wiring should be done almost entirely with SOLID wire though. Alas CORROSION like you'd get on sea-coasts can STILL ruin things. For that a VERY thin coat of solder serves well - wipe on a little flux and LIGHTLY tin and wipe. Just a few microns.

The most horrible mistake was back when they first introduced aluminum wiring for homes. The metal in the sockets/switches/etc were NOT super-compatible. Esp in 'corrosive' environs the connections would fail quite early - and start fires.

Remember - breakers protect against SHORTS, but can NOT detect bad connections - which get hotter and hotter as the resistance increases.

You get what you pay for. The 'discount' stuff from Home Despot or whatever will be 'functional', but for HOW LONG ? Alas, if/when it fails, it really might burn your house down.

Anyway, enough of Practical Power Electrics in a Pi group :-)