D-Sub connectors

[Geoff_H]

I definitely believe so.  Same technology just very different sized crimp machines.  The  high voltage cable swayed came with petrol driven hydraulic pumps and piston driven swage dies.  My crimper is mechanical advantage crimp that is getting harder to use as old age sets in 😒

[Geoff_H]

I should point out that when comparing HV cable connection it was with respect to corrosion in the joint, not electrical conductivity.  HV cables come with a steel cable for strength with conductors ( often anodised aluminium) wrapped around the outside.  At these voltages electrons repel each other and crowd the outside skin.  At these voltages you don't get electrocuted you get burner as the electrons run down the outside skin of the body. 

As another aside the aluminium conductors are often coloured to fit in with the surroundings, that makes them hard to see from the air as well.  Makes low level flying really dangerous.

[Jabiru7252]

Interesting comments on soldering. I worked for DSTO and we built many air-borne pods and other 'things' that were aviation in nature. We soldered. A good solder connection should be supported with mechanical support of the wiring. Some folks think they know how to solder, but they don't. Some think solder is a glue. I've been in the electronics game since the seventies, take it from me, soldering (done properly) is safe and reliable. Even satellites have soldered connections.

[spacesailor]

Glued soldered joints !.

DRY JOINTS.

Alway fail, especially  when temperature varies.

spacesailor

[onetrack]

You probably need to talk to some old PMG/Telstra lineys to learn about faulty soldered joints! Some of things I've heard them discussing - trying to find a line fault in a street pillar, and suspecting a dry joint, but being unable to find it - then having a heavy truck rumble past, and the dry joint promptly presented itself, with the vibration from the truck wheels! Or having an untraceable dry joint fault in a country phone line - so they'd pull off a couple of live 240V wires in the nearby exchange, and just touch them momentarily to the phone cables, to arc the faulty joint, and fix it! (the copper network normally ran on 48 volts DC).

[Jabiru7252]

Old PMG/Telstra lineys that would have been working on old PMG/Telstra soldering. And, if the liney couldn't find the dry joint until a truck went past, he should have resigned and taken up fruit picking.

[IBob]

On 18/01/2022 at 12:30 AM, spacesailor said:

Can l give you a long length of wire !.

Proberly  4 metres green anywere you cut it, was over 15 metres but tried very hard to find that elusive good end to crimp another terminal on.

Sea water travels uphill to ruin copper .

 Even up on roofs that copper will be GREEN.

spacesailor

 

Non-aviation thread-drift anecdote:
Back when I did industrial automation work, it was usual to install pressure transducers in the base of large tanks as a means of logging tank levels.

One freezing works I serviced had repurposed a couple of 10metre tall tanks for warm water, and I was called in to a failed level fault, determined that the transducer had failed. The duty sparky swapped the transducer, came and told me there had also been water in the transducer connector plug, which was unusual as the connector has it's own gasket and cable gland, and is normally watertight.

 

Meanwhile, the new transducer was blowing fuses, and when we opened the connector, we again found water. So the sparky stripped the insulation looking for dry wire. Then he stripped some more. And when he had stripped back 15metres along the run and we were still finding water, we gave up and put in a new wire run.

 

What had happened was that the diaphragm in the original transducer had failed, allowing water through the body of the transducer and into the connector block. And from there it was pushing it's way steadily up  our signal wire, due to the 10m head of water in the tanks.
Had we left it, it would eventually have made it's way all the way to the PLC cabinet that controls the water systems: yet another very good reason why we never, ever, used top entry for wiring in automation cabinets.......

[Geoff_H]

Soldering can be done properly, but the joint has to be restrained, that's extra weight in the aircraft.  It has to be done properly, a crimp tool takes almost all of the chance of error out.  Space craft don't vibrate after the trip to orbit, long term fatigue cracks would not have time to occur, atmosphere almost certainly not corrosive.  

[Geoff_H]

4 minutes ago, IBob said:

Non-aviation thread-drift anecdote:
Back when I did industrial automation work, it was usual to install pressure transducers in the base of large tanks as a means of logging tank levels.

One freezing works I serviced had repurposed a couple of 10metre tall tanks for warm water, and I was called in to a failed level fault, determined that the transducer had failed. The duty sparky swapped the transducer, came and told me there had also been water in the transducer connector plug, which was unusual as the connector has it's own gasket and cable gland, and is normally watertight.

 

Meanwhile, the new transducer was blowing fuses, and when we opened the connector, we again found water. So the sparky stripped the insulation looking for dry wire. Then he stripped some more. And when he had stripped back 15metres along the run and we were still finding water, we gave up and put in a new wire run.

 

What had happened was that the diaphragm in the original transducer had failed, allowing water through the body of the transducer and into the connector block. And from there it was pushing it's way steadily up  our signal wire, due to the 10m head of water in the tanks.
Had we left it, it would eventually have made it's way all the way to the PLC cabinet that controls the water systems: yet another very good reason why we never, ever, used top entry for wiring in automation cabinets.......

In explosive atmospheres the explosive gas can and will travel up the wire into a safe area ( not so safe then).  For safe installations there are sealing kits that use systems to stop the gas, only a few inches long but stop wire transfers.

[facthunter]

The crimp to be as tight as you say it can/must be would have to be much more substantial that required if it was soldered.  The tinning wouldn't have to extend far up the wire at all. If it does it destroys the covering/insulation.as well as making the wire rigid. Water can capillary along a stranded wire. Nev

[spacesailor]

Heavey restaining parts for holding your wire !.

Try ' super glue ', a little  ( a half inch ( American )) between the wire and what it leans on, works SUPER.,

spacesailor

[facthunter]

Like with any use of cannon plugs, the multi wire loom must be secured to something solid a few inches from the plug to avoid the wires breaking under vibrations that all engines have.Nev