I've been using Molex for 40 years. Here goes. Molex "production"
crimper is $115 US in Mouser catalog (www.mouser.com). Their
"prototype" version is $13 (Mouser #538-11-01-0015 for smaller .062"
pins, which also works on the Molex PC edge connectors ala King &
Narco).
Crimping is advantageous because, besides speedy and pretty, one part
of the connector is secured to the insulation by biting into it. But
the "prototype" crimper does a lousy job at that, especially on Tefzel
insulation, meaning that in lieu of the production tool, soldering is
still preferable. Why? Not so much because it will come undone by
itself, but users pulling apart Molex inline connectors may also pull
unconsciously on the wire bundles (Molex don't pull apart easy at all,
making fancy locking arrangements moot). So other than a perfect
insulation crimp is bad.
The rap against soldering is that some may wick into the insulated
part of the wire, providing more bending moment for breakage. Also,
excess solder on the bare wire part of the connection can concentrate
stress at the flat part of the Molex connector, making it less
bend-tolerant. However, good solder techniques minimize all this.
Use absolute minimum solder, train heat on the connector a bit before
heating the wire. Use needle-tip pencil and thin solder wire. The
tangs that are supposed to crimp into the insulation are too long for
neat, needle-nose crimping that will still fit into the nylon
housing. Snip the tangs down a smidge with sharp cutting pliers
before crimping. Work under a magnifying glass or hood, if one's
close-focus ability is showing up as the "second thing" to go with
age.
Stress on any connector soldered or crimped is nil when the result is
properly dressed. I do like good avionics shops do. For avionics PC
edge-mount, route the wires parallel to the connector, and ty-wrap the
wires in several places behind the connector with tiny wraps. If the
box mfr hasn't provided a strain relief next to the connector, add one
using a simple plastic P-clip (don't ty-wrap to antenna co-ax of
course). For inline Molex or similar, you want a service loop
anyway. Use enough wire to fold the result in to a "Z," connector in
the slanty part of the "Z," and ty-wrap the bundles on either side of
the connector.
As an aside, the Molex prototype crimper actually works very well on
those real tiny pins supplied with "D-sub" computer style connectors.
Soldering those things is not easy. Also, if you use inline Molex,
buy the $10 extraction tool. Well worth it.
Regards,
Fred F., A063
Rowland & Wilma Carson wrote:
>
> I had a query a while back from a member who's not online about a
> special crimp tool for the Molex connectors used on KY96A/97A radios.
> He had never seen such a tool and could not find anything like it in
> his Farnell or RS catalogues. The Molex reference number is 6115, but
> I'm now a bit hazy as to whether that was the tool or the actual
> connector number.
> ....
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