Best wire crimper

O.K. The AMP crimpers for P.I.D.G. (Pre Insulated Diamond Grip) terminals have two crimping areas. That for the electrical connection is like this "()" (except that one side of the die is closed on one half, and the other closed along the other half, so the dies open look like this (view with a fixed pitch font like Courier to avoid distortion and confusion): _ _______ |__ |__ (__ )__ _______| |_

so the wire part is crimped between the parens, and the sides keep the insulation from squishing out the sides.

And -- the insulation grip part is crimped with a section more like this (different scale to allow drawing it with ASCII graphics -- again use a fixed pitch font) _________ |___ |__ / \ \___ /___ _______| |_

which produces a diamond-shaped crimp on the insulation grip only.

There are pins holding the halves of the dies with three sets of mis-aligned holes -- your choice of a hole selects which size of insulation the grip will hold properly. Set it too tight, and it squishes out the larger diameter insulations. Set it too loose and it does not firmly grip the insulation

And of course -- this is only barrel style terminals. There are also (uninsulated) "flag" style terminals, in which the flags are bent into 'U's and the ends of the flags dig into the stranded wire. The crimp looks somewhat like this: _ / ) \_)

with the left hand side actually being a continuous curve, but I don't have oversized parens in the ASCII character set. :-)

These flag type crimp terminals are most often used in pins which crimp to the wire and then insert into the connector shell. Perhaps the most common ones are the pins for the DB-25 serial port connectors for RS-232, but there are larger ones for other different connectors, including the Molex ones, and AMPs own design of similar molded connectors. The crimpers from AMP for these various sizes will all say "Type F" rather than "P.I.D.G." or something similar.

The better ones have two sets of flags -- one for the wire connection and another for insulation strain relief -- and the insulation strain relief usually closes to close to a circle instead of the "flag ends in" pattern used for the connection part.

Note that *all* of the above are for *stranded* wire. Solid wire needs a different crimp style to make a reliable connection. And I normally don't use solid wire in combination with crimp terminals.

*That* is where the ratchet controlled crimpers win. You *can't* either mangle the right size terminal or crimp it too lightly. (Well, you *can* mangle it if you don't set it deep enough into the crimper so the connection crimp part misses the connection barrel. :-)

And this is not the best style for insulated crimp terminals.

BTW When you are using crimp terminals, you want the insulation stripped just the right length. With the insulation fully bottomed in the terminal, there should be just the very end of the wire extending out the flag or ring end of the terminal. If it is back inside the crimped terminal a bit, it is not properly crimped.

Yes -- there are places were crimp terminals can't be used, and solder is the right way to go.

And when stripping the insulation, a trick to avoid the ends of the wires fraying out is to just start the insulation off the wire, then note which direction the wire twists (yes, each batch is likely to be different from the previous batch), and twist the insulation in that direction as you pull it off. This causes the strands to lay tight, which is an assistance when putting the wire into a crimp terminal (having a strand point back beside the insulation is the same as crimping an undersized wire), as well as the ability to solder the tip together to prevent fraying under a terminal screw.

Or -- if you use anti-wicking tweezers you can keep just enough length unsoldered, and have the rest tinned, where you can then form the tinned section into a hook, hook it through a terminal eye (e.g. on a tube socket) squeeze it with needle noses for a good firm grip, and then flow solder once you have all the wires on that terminal.

For solid wire, not for stranded, IIRC.

Note that this design is intended to be a field repair tool, not a production assembly tool.

And aside from the ones which have the notched blades for each size of wire, for smaller wire this a similar one called the "Nickless", which has semi-soft plastic jaws which form around the wire and strip without nicking the wire. (Nicks are likely to make the wire more likely to break with vibration.)

Those temperature-controlled irons are particularly nice when dealing with soldering transistors or IC (to avoid over-heating), or when soldering to printed circuit traces, because too much heat will float the traces free of the board -- especially with the older (and cheaper) phenolic boards. G-10 glass epoxy is a lot better with heat, of course.

What about a solder pot for tinning a bunch of just-stripped wire ends at once?

Enjoy, DoN.

Reply to
DoN. Nichols
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On Sat, 28 Mar 2009 18:13:05 -0700, the infamous "Michael Koblic" scrawled the following:

That's always good. I've had great luck with a set of wire crimping pliers like the one on the right here:

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My pair was one of the tools in a $1 box from a yard sale.

In another sailing find, I grabbed a box of 9 stained glass soldering irons, a pound of solder, an eye lag, a packet of 4 lag hooks, a silicone jar opener, a tub of real TSP, a tube of clear 100% silicone sealant, and a quart thermos (stainless, with stainless tumbler top) for $7.30 last Saturday.

Reply to
Larry Jaques

Ah, tell me about it! If I had a nickel for each transistor I fried using the "pistol" soldiering iron...I would be in the poor house 'cos in those days tranistors cost 2% of average monthly salary. After taxes!

Reply to
Michael Koblic

For anyone still following this, here is an image (a bit crappy too, poor lighting setup, too lazy...) of a couple different "flag" or open barrel style terminals:

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The graph paper underneath has 1/6 inch spacing. These aren't very big terminals.

And the working portion on my AMP crimper for same:

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Don's text should explain these pretty well. There are two positions for crimping the insulation area. The ones labeled "E" and "F".

That type of crimper doesn't work very well on closed barrel or insulated style terminals. The open barrel style is usually much thinner material and doesn't take as much crimping pressure to form.

I used to use a lot of these style terminals doing two-way radio repair...

Reply to
Leon Fisk

Leon I have one in the UK it is probably my most used "Nom-Insulated Crimp" crimper. Perfect for just about everything from "D" connector crimps upwards. I suggest that you show a photo of the whole unit so if anyone sees one going cheap they will recognise it and snap it up Bought mine for the equivalent of $5 about 30 years ago IIRC.

Richard

Reply to
Richard Edwards

Well, I figured a picture of the whole tool would be easy to find. But it would show little detail in the crimping area.

Mine was called "Service Tool I" and was made by AMP. This appears to be the same tool, but the image with it is wrong:

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The description seems right and the link for the instruction manual is good:

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and shows the proper tool. I'll have to look that over, I don't remember mine coming with any instructions. I did buy it new too and it wasn't cheap for such a simple crimper.

If you use a lot of open barrel or "flag" type terminals this is about the cheapest way to go. Unless you get lucky and find something used cheap. I rarely get lucky finding stuff like this used...

Reply to
Leon Fisk

That would make it real hard to get your new metal home, wouldn't it?

Reply to
Michael A. Terrell

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