Bumper Question

[EricH]

Without seeing the design, I'd probably be inclined to say no right away...

BUT!

I think you may be reading the rules wrong. That's OK, you're rookies.

So, here's what we'll do: I'm going go through the bumper rules, noting things that can help you. I will also note that anything on CD is unofficial.

So, <R07>, here we come. Parts A through E are construction, not mounting (other than location).

F. Each BUMPER segment must be backed by a piece of ¾” thick by 5” tall piece of plywood. Small clearance pockets and/or access holes in the plywood backing are permitted, as long as they do not significantly affect the structural integrity of the BUMPER.

Those pockets are for bolt heads. If you're relying on bolt heads as structural backing for the bumper, I'd suggest making those pockets, and using the frame as your support.

Back to <R07>, parts G through J are construction/covering. So we skip those for now (though if you want clarification on those, speak up!)

Now, the part you're having trouble with, <R07-K>. There are two parts and some definitions that can be confusing, so I'm going to take this slowly.

BUMPERS must attach to the FRAME PERIMETER of the ROBOT with a rigid fastening system to form a tight, robust connection to the main structure/frame (e.g. not attached with Velcro). The attachment system must be designed to withstand vigorous game play. All removable fasteners (e.g. bolts, locking pins, pip-pins, etc.) will be considered part of the BUMPERS.

Frame Perimeter is in all caps, as are Bumper and Robot. That means that we go to Section 1.6 for the definition:

FRAME PERIMETER – the polygon defined by the outer-most set of exterior vertices on the HOSTBOT (without the BUMPERS attached) that are within the BUMPER ZONE. To determine the FRAME PERIMETER, wrap a piece of string around the HOSTBOT at the level of the BUMPER ZONE - the string describes this polygon.
Note: to permit a simplified definition of the FRAME PERIMETER and encourage a tight, robust connection between the BUMPERS and the FRAME PERIMETER, minor protrusions such as bolt heads, fastener ends, rivets, etc are excluded from the determination of the FRAME PERIMETER.

That, right there, is where you're making your mistake. You're off the Frame Perimeter because of those bolt heads, which are specifically excluded from the Frame Perimeter (but not the sizing box--two different things there; further explanation on request). See the note on pockets above.

<R07-K>, part 2:

The BUMPER backing must be supported by the structure/frame of the ROBOT (i.e. the gap between the backing material and the frame must not be greater than 1/4” and no section of BUMPER greater than 8” may be unsupported). See Figure 3-3.

Bolts do count as structure... but what they're attached to is stronger. Also note that Figure 3-3 shows a 10" long by 1/4" deep gap as being legal.

So, here's what I think about the bumper attachment currently: You're off the frame perimeter, I'm not certain you're adequately backed by frame, but you might pass inspection, depending on your inspector and their degree of leniency.

There is a quick fix, though, so if you can get to the robot before ship/bag, you should be able to be very legal in attachment. With the bumpers on the robot, mark where the bolt heads are. Take the bumpers off, get to the plywood backing, and take an appropriately-sized drill bit to the spots where the bolt heads are, going deep enough to allow the bolt heads to be completely inside the plywood. Do whatever slight tweaks you need to to make your mount match the new location, about 1/4" closer to the frame, and you should be legal just about anywhere, barring other bumper rules violations that you haven't spoken up about (hopefully none).

You may also want to get the Inspection Checklist and go over the robot to make sure that you're in compliance. It's on the FIRST site, alongside the Manual. (While you're at it, do a version check of your copy of the Manual--you'd be surprised at what has changed since Kickoff.) You'll still need inspection at competition, but if you catch stuff even a day before Ship Day, you can plan on how to get within the rules quickly.