I couldn’t find anywhere in the rules but we have around a 1/4 inch of space on the front and back
Is there a limit of how much space you can have at the front and back between the drive base and the bumpers?
That’s the limit if that gap is more than 8" wide. See R26. (Emphasis mine.) I suggest you try to get it smaller; the larger this gap, the more the bumpers get beaten up on every collision, and you also aren’t risking a problem with an RI who decides it’s 17/64". No gap is best of all. If the gap is between your wood and the frame, you may be able to add some plate or angle to fill in the gap. If you do this, watch out for R24B.
R26. BUMPERS must be supported by the structure/frame of the ROBOT (see Figure 9-8). To be considered supported, a minimum of ½ in. (~13 mm) at each end of each BUMPER wood segment must be backed by the FRAME PERIMETER (≤¼ in. gap, ~6mm). “Ends” exclude hard BUMPER parts which extend past the FRAME PERIMETER permitted by R24-B. Additionally, any gap between the backing material and the frame:
- A. must not be greater than ¼ in. (~6 mm) deep, or
- B. not more than 8 in. (~20 cm) wide
R24B: hard BUMPER parts allowed per R24-A, -E, -F, and -G must not extend more than 1 in. (~25 mm) beyond the FRAME PERIMETER
Some RI’s use a gauge that is 1/4" thick and is used to check the gap. If it goes in and wobbles around, the bumper fails. You might want to find something that is 1/4" thick or use a 1/4" drill bit to do a check yourself.
Or maybe a 15/64 drill bit…