Problems With The Power Distribution Block

[Al Skierkiewicz]

Originally Posted by Brandon Holley

At the winter warzone we had all kinds of problems with the block arc-ing and causing our victors to short out. It cost us the quarterfinals there.

At 12 volts these blocks cannot arc. Intermittant wiring will cause heating and intermittant electrical power can cause problems with any electronics. All termination devices at normal robot currents will have these problems including the interface to the battery terminals.
The Rockwell blocks use quasi-parallel clamps to secure the wires. If a wire is not stripped back enough or if the wire is not inserted far enough, the clamp will squeeze/push the wire out of the terminal. If you take a look at the picture (thank you to the Rockwell site) you will see that a wire that is not inserted to the end of the clamp will loosen and fall out. The specification from the Rockwell Catalog for this series (1492-J16) is "Wire Strip Length 0.63 in (16 mm)". The molded-in wire stop correctly positions the wire in the jaws for best termination. Additionally, stranded wire will be forced to change cross section as the clamp pushes down on the wire. This may force teams to check the tightness from time to time. (robot movement will shake wires and make this worse) For these reasons, Loctite is a bad idea on these blocks.
Some folks have suggested the use of ferrules over the wire. Debate is still raging but i have some Panduit samples coming in the next week or so to look over. stand by...