what is the size of the electronics

[Jon Stratis]

Originally Posted by Don Rotolo

Note that last year's rules had some specific language as to which lights needed to be visible, and you need to consider the 2010 rules as well.

Also, for what it is worth, anything you design (or build) prior to kickoff really is not eligible to be included on your 2010 robot, assuming the 2010 rules are similar to all previous years rules in this respect. But this is a good time to think about concepts and such.

Not exactly... What you're talking about is <R24> from 2009 (the number is probably different in previous years, but the intent has always been the same). it states:

Prior to the Kick-off: Before the formal start of the Robot Build Season, teams are encouraged to think as much as they please about their ROBOTS. They may develop prototypes, create proof-of-concept models, and conduct design exercises. Teams may gather all the raw stock materials and COTS COMPONENTS they want. But absolutely no final design, fabrication, or assembly of any elements intended for the final ROBOT is permitted prior to the Kick-off presentation.

Based on the rule, teams are encouraged to do this type of thinking and design in the off-season - you simply can't use any final designs or assembled components.

For example, it's going to be nearly impossible to determine how many Jaguars, Victors, and Spikes you'll use from year to year - so how can you design a box that would include everything?

If the OP takes the dimensions and develops some general designs - for example, by doing some example layouts and determining the pro's and con's of different wiring strategies, some valuable skills can be learned - and when the season starts and the specifics of the robot are known, that information can be put to good use.

Plus, the room available for the electrical system changes every year based on robot design... there's no way we could use the same electrical board year to year. Our team has developed some ideas concerning that (although no detailed designs yet), so stay tuned... it should be pretty nice.

[Al Skierkiewicz]

Pat,
There is a lot to be said for distributing electrical components to minimize the length of wire in high current branches. Often teams will attempt to make things look really nice while causing excessive wire resistance to compromise the operation particularly in auto mode. The addition of 4 feet of #10 wire to one side of your drive can lose you almost 0.5 volts at near stall delivered to your CIM or FP motor. Sometimes it is unavoidable but too often teams forget that pretty isn't always good.

[Jon Stratis]

To support what Al said... back in 2008 (Overdrive) our robot operated more or less like a forklift in order to lift the ball 7 feet in the air. On the lift were two motors designed to "suck in" and hold the ball in place, and later "spit it out". The wires running to those two motors were something like 14 feet long.

We saw a HUGE voltage drop across those wires (so large, in fact, that the motors couldn't do their job). The design of the robot didn't allow any other options for running the wire... so our options were to use a larger diameter wire (which would reduce the resistance, but decrease the flexibility in the wire as well), or run multiple wires in parallel. We went with the second option, which earned us some questions (and then compliments!) from judges and inspectors - each spike had 2 m+ and 2 m- wires, and each motor also had 4 wires going into it. Perfectly legal configuration (and it cut the voltage drop in half), but at first glance it appears as though we were either trying to use 2 spikes to power each motor, or trying to power 2 motors from each spike.

Voltage drop across wires is real, and it can have horrible affects on your robot. Any time you have two motors that need to work together, or extremely long lengths of wire, you'd better consider this!

[Al Skierkiewicz]

Originally Posted by eagle33199

We went with the second option, which earned us some questions (and then compliments!) from judges and inspectors - each spike had 2 m+ and 2 m- wires, and each motor also had 4 wires going into it. Perfectly legal configuration (and it cut the voltage drop in half), but at first glance it appears as though we were either trying to use 2 spikes to power each motor, or trying to power 2 motors from each spike.

Eagle,
I remember inspecting your robot. It is more accurate to say that the rules did not prevent it, than it was legal. Your design satisfied questions I had about safety and electrical circuit protection. It is too hard to discuss here so that everyone will understand but it did satisfy any questions or fears I had under the rules at that time.

[pat.rick.kelly]

Thanks I will keep that in mind