For this year’s competition, our robot’s frame is designed with two levels (Like a sandwich)… One is the lowermost part of the frame at 28" by 38", about 4" from the ground. The second level is supported directly above the first level with the same dimensions. The rules state that the bumpers on the sides of our robot must be located between 2-10" from the bottom of our robot.
My question is, if the upper and lower levels have the same dimensions, and the upper level is located 10" or greater from the bottom level, will we need to make two sets of bumpers: one for between 2-10", and another for the section of the robot that exceeds 10" in height?
No. Bumpers are only to be mounted between 2 and 10 inches from the ground, where the bumper zone is.
Also note that a 28" by 38" robot, if you aren’t including bolt heads in that measurement, will most likely not fit in the sizing box, forcing you to rebuild your robot slightly smaller. Most teams design an inch undersize in any given direction to allow for bolt heads and other miscellaneous stuff like that.
I completely agree. Design for 27"x37" max. If your bot is in any way not ‘square’ and the top leans a bit, it won’t fit in the sizing box. Also, you need to account for bolt heads and so forth as well (though we typically size our bots 27x37 before accounting for bolt heads.)
Minor protrusions(nuts, bolts, etc.), according to the rules, are allowed beyond the frame perimeter, so you can build close to the frame footprint dimensions if you need to. It is always a good idea to allow for out of square and robot rock to ensure you will pass inspection.::rtm::
Last year we were a hair too long (about 1/8" - 1/16"). We were also over weight (though we anticipated this and had a contingency plan). Cutting your robot to fit in the box is not fun. Thankfully a team lent us a portable band saw and made it a lot easier for us. But still not fun. It took us all of Thursday to get everything running properly again.
I know it might be hard to filter out the answer from above posts. You must conform to the bumper rules in that only one actual bumper system can fit on your robot between the 2" and 10" above the floor. (the dimensions allow only 8" while a bumper that is correctly constructed will be at least 5" high) It is possible and legal however, for parts of your bumper system to mounted low and others to be mounted high as long as all of the rules for bumpers are followed. Specifically, the minimum 8" segment on either side of an exterior vertex and all bumper construction rules.
There is only one set of bumpers on the robot. The things that you mount higher/lower than those bumpers may look and act like bumpers, but they are not. As such, they need to be inside of the frame perimeter and not directly above/below the real bumpers.
Since your upper frame is the same size as your lower frame, a bumper on the upper frame would actually be prohibited. At the start of the match, nothing other than the Bumper may be outside the frame perimeter ([G01]). The bumper on the upper frame may be functionally a bumper, but would not actually count as a Bumper for rule purposes ([R01-2], [R28-E] and [R29]).
So, anything that is not an official Bumper (even if it looks and functions like a bumper) counts as part of the main robot, is part of the 120 lbs limit (excluding battery), and must be inside the perimeter at the start of the match. After the start, a bumper-ish thing could be part of an appendage that may extend up to 14" past the perimeter.
[EDIT] Oops, I didn’t notice the post by LinuxArchitect before I submitted my post. Sorry for the redundancy.
There may be nothing outside of the frame perimeter except bumpers in the bumper zone. All other devices whether they look like bumpers or not, and whether they are mounted in the bumper zone or not, are illegal. The only exception is one appendage that must be inside the frame perimeter while in the starting configuration.