Re: shielding for steppers

Hi,

I respectfully disagree. A proper crimping tool cinches the connector
metal around the wire strands and curls the ends into the wire
strands. This forms a circular, gas-tight seal between the wire and
connector.

Pliers "flatten" the pin termination around the wire. The result is
there is very little if any contact pressure because the connector
metal is cantilivered.

You can test this for yourself by pulling on the "connected" wire.
Almost certainly you will feel some back and forth play between the
wire and the pin, if indeed the wire does not come free of the pin
altogether.

Soldering presents its own problems. While certainly making an
excellent contact, it makes the wire much more prone to fatigue
failure if there is any flexing involved. This is because the bending
radius will much smaller and this will act as a stress concentrator.

There are a few things that can be done to insure the best possible
solder joint.

Do not use a knife to strip the wire insulation. Any resulting nicks
in the wire strands will concentrate stress even further and
prematurely fail the connection. Use hot wire strippers or even your
teeth instead.

Use a good rosin-core solder(Kester 44)and allow the solder to wick
up the wire under the insulation if possible. This will permit a more
gradual transition from soldered to unsoldered wire strands, allowing
for a larger bending radius. The insulation will offer strain relief.
Finally tie off and anchor the wire harness way beyond the solder
joints to prevent flexure at the connector. If it cant flex, it can't
fatigue.

Mariss


--- In CAD_CAM_EDM_DRO@y..., "Carol & Jerry Jankura"
<jerry.jankura@s...> wrote:

> With the exception that an "improperly" crimped terminal might not

fit into

> the housing for which it is designed, I don't think that you'd have

any

> problem by using a plier to crimp the terminals to the wire, and

soldering

> them to the terminal is a plus. Now, this is for standard electrical
> connectors. If you're talking about something like BNC connectors

that

> require a proper "impedance" it's a different issue. With these

connectors,

> you've got to be very careful that the wire is crimped properly so

that the

> impedances match.
>
> -- Carol & Jerry Jankura
> Strongsville, Ohio
> So many toys, so little time....
>