PWM Extention Cables: 4 Shall Be the Limit

[Joe Johnson]

From an e-mail between FIRST VEX Challenge teams:

Hey all,

This is TJ from team -Stickshift FRV 51- (First 1688) .
...<snip>...
We are experiencing a problem that I think you all might be having. The
rules say that were only allowed to use 4 pwm extension cables for the
servos and motors. These cables are nowhere near long enough to power the
manipulator to the full extended length and still have enough left to power
a drivetrain (with a 24 inch chassis....we would need at least 10-12 inches
of cable on each motor to safely route the wiring to the control module. Any
takers on this one, because were stumped as to why using more than 4
extension cables would be banned (as per the FRV robot inspection sheet). I
don't know if were missing something..maybe we are...if so....shout out to
us...



Thanks

~TJ

Dr Joe's Answer:

...<snip>...
As to his question, the 4 PWM extention cables are part of the design challenge.
I think it is probably an unreasonable restriction giving the size of the
robots (it effectively limits/makes impossible the use of powered end
effectors), but it is one of the limits. I could go with FIRST changing the
rules (in fact, I recommend it), but if they don't, teams will have to work
around it.

Joe J.

Hope this helps.

If you have questions or answers or opinions or whatever feel free to join the conversation.

Joe J.