Given an exciting event on the weekend where a robot ‘let out the magic smoke’ we (in New Zealand) have been forced to carefully consider the rule <R15> (relevant parts below) allowing teams to repair cables.
The repair of a 3 wire cable ‘gave way’ during a match with the result that the cable shorted and the section between the repair and the cortex got so hot with the high resulting current that the insulation surrounding it melted and substantially smoked. Damage to the Cortex itself almost certainly occurred. The amount of insulation tape used was insufficient to withstand the rigours of competition.
The health and safety implications of having a battery shorted out in this fashion without being able to disconnect it without pulling out the battery cannot be ignored.
Given that insulation tape is regarded in industry as a temporary fix we are not totally surprised that this occurred.
We now believe that electrical tape is not a reliable or safe way to repair damaged cables and presents a health and safety issue. The robot in question could not be turned off and we suspect that the on/off switch was damaged in the overcorrect event.
Ruling in New Zealand
All repairs to damaged wires should be now be carried out using the correct size of heat shrink for the wire. This will involve cutting and soldering wires to repair them. Any repairs that currently use insulation tape should be reworked to conform to this.
Wires that are not repaired in this way WILL fail inspection in New Zealand.
We stongly suggest that all VEX teams follow this standard to protect their investment.