[thursam]

I don't see a rule prohibiting it, but there are some you have to keep in mind...

•R13
ROBOT elements created before Kickoff are not permitted. ROBOT elements, including software, that are designed before Kickoff are not permitted.

Exceptions include the following:
A. BUMPERS,
B. OPERATOR CONSOLE,
C. battery assemblies per R5-A, and
D. software and designs with source files publicly available prior to Kickoff.

•R3
The ROBOT must satisfy the following size constraints:
A. the total length of the FRAME PERIMETER sides may not exceed 112 in. (see Figure 4-1 for examples),
B. a ROBOT may not extend more than 20 in. beyond the FRAME PERIMETER (see Figure 4-2 for examples) (see G24), and
C. the ROBOT height may not exceed 60 in., except as allowed by G23.
D. Any extension above 60 in. may not exceed a 6 in. diameter vertical cylinder (see Figure 4-3 and Figure 4-4 for examples), per G23.

Those are the only rules that I can find that would limit anything on your robot.