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Originally Posted by RbtGal1351
Hello all,
I am wondering what fixes teams have come up with to ensure a good connection between the Victor Speed Controllers and its PWM Cable.
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The wadded up extra length of the pwm cable can present an extra
bit of mass that wiggles the cable when the robot moves. We cut
our PWM cables to the required length, replacing the female end with
a Molex C-grid connector, using the "high force" sockets. We don't
use the C-grid connector on the male end, the pins seem to be too
short to make a good connection to the victor/spike.
The cable itself is zip tied to the electronics board right next to the
controller, or the victor, so that the cable comes up and over with a
inverted U shape, providing for stress relieve in the event of impact.
Attaching the electronics so that the force of typical impacts is
perpendicular to the connector, removing the tendency of the impact
to pop it out, is a good idea.
We check all of these connectors between every match to make sure
that none are walking off, and we keep track of any that might be
moving. If it moves a half millimeter when you push a little with your
fingernail, it is walking off and you need to do something about it.
There is no substitute for checking the connectors between every match,
and laying out the electronics to make it easy to do this without bumping
wires, but you can take measures to improve things:
* You can make a bracket that pins the connectors down when
it is screwed to the electronics board. With due attention to the
possibility of a short, the 3 dollar clip available at robot marketplace
would seem to work for a victor, but you need a single bracket to
hold a large number of connectors on the RC. I would want these
brackets to be made of plastic to reduce the chance of a short,
but the aluminum ones on our robot this year were insulated
with electrical tape. If you have th luxury of using every other
PWM output on the controller, you can make a "comb" style of
bracket that will hold the connectors better.
* Another strategy is to glue the female connectors to each other
as you install them on the RC, producing a single connector with
a large pin count. The resulting high pin count connector is almost
impossible to walk off, although you can get if off if you need to.
The drawback here is that if you need to replace one cable for some
reason you get to do some cutting, but it produces a connector that
does not walk off without using a bracket. We use this strategy for
the array of switches used to provide autonomous modes, or inhibit
motors for safety in the pits, that are connected with a single multi-
conductor cable.