BP horizontal attachment

According to Joseph Gwinn :

That can work -- but it can be a bad choice if the terminal is subjected to vibration. The solder wicks up to the insulation and stops right there, and any flex from the vibration is concentrated in that one spot -- resulting in eventual failure at that point.

The crimped terminals leave a bit more length of solder-free wire, so the flex occurs over a longer stretch, and the wire lasts longer.

And the *good* crimped terminals -- the pre-insulated ones with a P.I.D.G. crimper will collapse the rear of the insulation sleeve to grip the insulation, thus reducing the flex at the terminal. In particular, the AMP terminals for the P.I.D.G. (Pre Insulated Diamond Grip) have a sleeve of metal shim stock around the terminal barrel and inside the insulation, with the last bit folded back to the edge points towards the terminal. This bites into the insulation to grip it more firmly than possible by just collapsing the plastic insulation to form a grip.

This is why these terminals are particularly preferred for aircraft applications -- when it is quite awkward if certain electrical connections fail while you are aloft -- and they *never* seem to fail on the ground. :-)

Enjoy, DoN.

In my experience, the biggest problem with failure of crimped terminals is that the installer did not use a proper crimping device, or the unit was not calibrated with a go no go gauge. The cheap stamped out crimping might be ok for household use but they spring and don't do a secure crimp. A good T & B forged crimping tool is a lot better way to go than the stamped ones if you can find one used in good shape. The best crimpers are the ones that have a racheting system that will not release until the proper pressure is put on the crimped terminal, but these crimping tools must be checked periodicly with a go no/go gauge. Overcrimping is as bad as under crimped terminal. Overcrimping cuts the wire and although the terminal looks like a good crimp a number of wires are cut and the terminal is held on mostly by the insulation. On the high end crimping tools, there are identification marks that are on the crimper that leave the same mark on the crimped terminal so the inspector can tell if the terminal was crimped with the right tool.

John

I used such a ratcheting crimper when I was installing Cat6 cabling as part of upgrade of my house to Gigabit Ethernet. I was very impressed with the consistency and quality.

That is logical - often done in cooler areas. How about silver solder. The lower temp versions are just perfect. Then if the joint gets hot due to heat sinking an arc the joint will be solid for a higher duty cycle.

Mart> >

Don - must use your Anti-skating tools that keep the stranded wire free from wicking. That is mil spec requirement since lets say years before the moon. :-)

Martin

Mart> According to Joseph Gwinn :

We had a set of drawers cabinet - roll around in the R&D lab - that held drawers in the bottom of different sizes of crimpers and the other dozen held the crimp dies for the many handles.

Martin

Mart> >> go than the stamped ones if you can find one used in good shape. The

They are -- at best -- emergency field repair tools, and the crimp should be re-done with a proper tool when you are back home (or wherever the proper tool is).

This describes the AMP tools which I was suggesting upthread.

Right -- red (22-16 ga) is one dot, blue (16-14 ga) is two dots, yellow (12-10 ga) is back to one dot, but there is sufficient difference in size so there is no way that a terminal crimped with one size of one dot tool instead of the proper one dot tool would pass the simplest visual inspection.

Once you get past 10 ga, the rest (all hydraulic in my set) emboss the actual gauge number in the insulation barrel, because it is now big enough to read easily.

Enjoy, DoN.

According to Martin H. Eastburn :

You mean anti-wicking tweezers? Yes, but I don't think that I have seen any large enough for the 6 ga wire which he described as having soldered terminals to -- and he certainly did not mention the use of such tooling.

If you *must* use solder -- such as when connecting to the solder-tail terminals on a relay socket or something similar, then the anti-wicking tools are mandatory -- at least in any kind of application where the assembly is subject to vibration, and a person's life depends on the circuit continuing to function.

Enjoy, DoN.

Yea them - several terms I suppose. My George C. Marshall Space Flight Center booklet from Quality division circa 1961 gives them a general term of Heat Shunt.

Can be wide tweeters or the custom sets by gage wire as Don mentioned. The skating term - is Air force. Solder wicks up the strands - or skates. (I suppose).

You could wrap a bunch of tin foil tightly around the end -

Martin

Mart> According to Martin H. Eastburn :

I didn't bother, as the application was both stationary and not safety-critical. The application was connecting up a new stage-light dimmer panel at a high school.

Joe Gwinn

But the insulation will have long since burned away?

The code, which is very conservative, allowed use of soft solder. I asked a friend who is an electrician and contractor if solder was still allowed by the code, and he said that he believes it still is. My copy of the code is old, so I cannot check.

Joe Gwinn