Victor-PWM Cable connections

[eugenebrooks]

It is indeed the case that we are having a lot of problems with intermittent connections on the victors, and presumably the spikes as well (our team is not using them this year). A new cable does not work, you take it out and inspect the crimps and it is perfect, you plug it back in and it may work, or it may not. Get another cable, it works, and then if the cable is moved or replugged, you find it does not work.

We are finding that the fit of the metal pins on the cable into the corresponding socket on the victor or spike is loose when this problem happens. In addition to all the recommendations above with regard to proper tie down of the cable to prevent movement, you can spread the metal pin a little in order to cause the socket to get a better grip and produce a little insertion force.

If you look at the metal pins, they are made of stamped metal and have the shape of a U. If you can find a suitable tool (a wire cutter that has a flat side on one of its yaws works, or a small end nipper with one jaw ground flat will work), you can spread the U just a few thousandths and as a result you will note that the socket will increase the previously non-existant insertion force. At this point the connection should not be intermittent. It is important that you don't overdo this, just a spread of a few thousandths will produce a little insertion force and then the gold plated contacts will do their job for you. You can measure the spread with a dial indicator to make sure that you are not overdoing it, you don't want the spread pin to force the socket contacts past their spring limits.

It would be nice if IFI would use "high insertion force" sockets when victors and spikes are made, or carefully screen the components that they use for this critical, and very problematic, connection. The high insertion force sockets and pins I buy from Mouser have a good grip for a single pin, so it would seem that a good grip could be obtained with the socket in the victors and spikes by using high insertion force parts.

With a little insertion force on the socket, you will find that the connection will have less tendency to walk out and become unplugged.

Have fun,
Eugene

Originally Posted by Donut

This is a year old thread, but the problem for us is arising this year.

We have had extremely bad unseating issues with some of our spike relays on this year's robot. Sometimes there's no connection, sometimes there's only a connection for forward or reverse, and sometimes they work fine. Do any teams have methods of attaching PWM cables to spikes better, or know of any "alligator clips" that will work with Spike Relays?