sonny junell

sonny junell

Well Known Member
Why should i used the pin / socket insertion style d-sub's (solder "or crimp" then insert pin in to the sub frame) vs the solder pot style where my only step is solder and be done?

Thanks for any input.
 
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The machined stlye pins/sockets are the best, crimp and install, no solder required. They are more reliable, easier to work with and of course... a little more expensive :D
 
Easy replacement if a pin fails or breaks, easy addition of new pins if you haven't filled them all, easier to attach wires and then insert into connector as opposed to trying to solder in close proximity to other pins. Those are my top 3.
 
Keeps the wire flexible

We use the crimp style at work because the solder can wick up into the wire making it more brittle at the pin. This is not a problem if you have a good strain relief but if the strain relief is loose you can stress the wire to the breaking point. In the old days the Air Force did not allow soldered pins for this reason
Hope this helps,

Paul
YMMV
 
But even NASA...

pczar3 said:
We use the crimp style at work because the solder can wick up into the wire making it more brittle at the pin. This is not a problem if you have a good strain relief but if the strain relief is loose you can stress the wire to the breaking point. In the old days the Air Force did not allow soldered pins for this reason
Hope this helps,

Paul
YMMV
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...does allow soldered joints if done to specification.

Check 6.14 here - http://workmanship.nasa.gov/lib/insp/2 books/frameset.html

Soldering is OK if the wires are supported correctly in the shell strain relief. However, the dimensions are small in the solder cups and you might actually find the crimping easier.

Lots of electronics has historically been soldered and has worked fine under all sorts of vibration and stress, including all of the early stuff on the moon and Mars - my first US job in the early 70's....:)

PS - the Air Force also used lots of Hughes Aircraft missiles, satellites and radars with lots of soldered joints in them...:)
 
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... and when you are upside down underneath your panel, it's hard to hold a soldering iron in your teeth, solder in one hand and the wire in your second hand.

The solder splash burns take a while to heal.

Vern
 
Third hand...

vlittle said:
... and when you are upside down underneath your panel, it's hard to hold a soldering iron in your teeth, solder in one hand and the wire in your second hand.

The solder splash burns take a while to heal.

Vern
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LOL - Never tried holding the iron in my teeth! And of course holding the connector (or whatever it is you are soldering to), in your third hand.
 
vlittle said:
... and when you are upside down underneath your panel, it's hard to hold a soldering iron in your teeth, solder in one hand and the wire in your second hand.

The solder splash burns take a while to heal.

Vern
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HAHAH Yeah , that would definitely happen to me,


OK I am sold on the crimp pin / socket style thanks for the feedback
 
After making wiring harnesses both ways, I will never use a solder cup connector again if I can help it. Once you have the tools, it's quicker, easier, cleaner, and requires fewer hands (only two!).

As mentioned, strain relief is important (for either method), but there are also issues with flux residue that is chemically active and can corrode the wire years down the road.

If you're new to it, it will take a while to get great crimps every time, but after a few hundred crimps there is no going back.
 
sonny junell said:
That is a great site< THANKS
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Lots of good info there.

One note of caution...there's a tendency to say "Look! NASA allows _________ so it must be okay for just an airplane!"

NASA does not just allow anything...be it crimp or solder, one type of connector vs. another, various wire types, one alloy or metal as opposed to another, EVERYTHING is engineered, analyzed, modeled and tested to make sure the correct decisions are made.

The mere fact that NASA has a standard that allows for solder joints (or crimps, or anything else) does not mean that a technician is free to choose whatever he wants. The engineers decide what's to be done based on very, very rigorous work.

You can't use NASA standards and specs out of context. They are part of larger *systems* of engineering.
 
vlittle said:
... and when you are upside down underneath your panel, it's hard to hold a soldering iron in your teeth, solder in one hand and the wire in your second hand.

The solder splash burns take a while to heal.

Vern
Click to expand...

Hi Vern, Just a note too let you know your AMX-2A I purchased a couple of years ago is still going strong! Love it. Thanks! And, to keep this on topic, I did use crimp style pins.

Steve
 
N282S said:
Hi Vern, Just a note too let you know your AMX-2A I purchased a couple of years ago is still going strong! Love it. Thanks! And, to keep this on topic, I did use crimp style pins.

Steve
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Thanks for the support Steve.

Of interest, back in the late 70's, I was designing the DC drive controller for an electric vehicle. I had an eager young lab assistant with me. I was in an awkward position and asked her to pass me the soldering iron, which she did.

I still remember the sizzling flesh.

She ended up with a PhD, working for Hewlett-Packard. Go figure!

V
 
True...

Ironflight said:
Thank You Steve! Very succint, very true,and much shorter than they way I was thinking of posting a similar thought....;)
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...but if you are going to use a specific technique, the NASA standards do show how to use it to a high standard, with good/bad examples and numbers.

For example, how many builders here know that for a 20g or smaller crimp on a D-sub pin (this thread...:)..) that there should be between 0.010 and 0.030 of bare wire exposed at the entry to the pin?

If you do not have this dimension, then structural issues could occur by building crimp joints out of their original design spec.

A lot of the specs in the NASA document are for "piece items", and yes they are called out for by the system drawings, but they also exist as individual techniques.

There may be discussion on crimp vs solder, but both have been used in many high stress aerospace situations.

When I started in aerospace, crimp pins in military connectors did not even exist, and yet interconnections managed to get made.

Crimp and solder cup are both acceptable techniques, and that is why military (aka high stress) connectors are still made in both versions.

Whichever version you use, assemble it per the manufacturer's instructions, or for more generic parts, the NASA documents show "good" techniques.

Don't knock well made solder joints, they made it to the moon and Mars on my designs, and the vibration spectrum of a rocket launch (Saturn/Titan) easily out vibrates our Lycomings....:D
 
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Thanks for grounding the discussion Gil...

Occasionally I see we get all twisted in a level of discussion that goes way beyond what's required. When I started my build a year ago I said, ''Whats a D sub and does it have anything to do with the Navy?" I am now crimping Dsubs and appreciate the NASA reference as a guide to good vs bad work. I have a box for my ''bad'' work. :)
 
One additional reason to use crimp pins vice soldered cups I didn't see mentioned here is that crimp pins can be pulled through small pass-thoughs, like grommets or plastic bushings in sheet metal. I can think of many applications where I have one connector on one side of a bulkhead or firewall and another connector on the other side. With soldered connections maintenance requires the connector to be cut off to remove the cable. With crimped connections you can remove the pins from the connector, feed them through the pass-through, and reinsert the pins. Big advantage in many cases!
 
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