[KenWittlief]

I would say dont use CF.

The main reason is: your robot is really an engineering prototype. During the final stages of build and test, and at regionals and the championship it is very likely that

A. the robot will be seriously damage and will require extensive repairs (not only on the field, but you have to consider things like your crate being smashed, or dropped off a forklift from 6 feet in the air - it happens! )

2. You will want to make changes to your robot, possibly major changes.

For these two reasons its best to have a frame structure that is easy to repair and modify. Cutting, drilling and grinding on a CF frame in the pits at a regional would put hazardous materials into the air.

Carbon Fiber would be a good choice after the prototype stage of an engineering project. For example, after the year is over, and you have refined your design, and you want to make 1000 robots a year and sell them. At that point all the bugs would be worked out.

Unfortunately, FIRST robots never get to that part of the Engineering Design Cycle.