Detatchable Bumper Frame

Our team has bumpers that are attatched to a exterior metal frame, not directly to the frame of our robot. To switch from red to blue, we are planning on removing the entire metal frame. If the frame is identical, do we need to include the weight of both frames in the weight of the robot, or is it considered a “replacement part?” My team thinks that they will be replacement parts, but we want some other opinons. Thanks!

I’d check <R07-J> and <R07-G> first, then ask Q&A about the configuration if you still have questions.

An interesting question. My first instinct was “yep”, they’re seperate configurations and need to be included in overall weight… but the “replacement parts” argument was interesting.

If you look at the definition of a replacement part, however:

REPLACEMENT PARTS – A COMPONENT or MECHANISM constructed as a functional duplicate of an existing part of the ROBOT, for the purpose of replacing a broken or defective part.

and specifically the section I have placed in bold, I don’t think that swapping out perfectly functional bumper mounts is within the intent of the definition of a replacement part. You could ask the Q&A forum, but in this case, I think the rules are pretty clear.

Your bumper mounts are only a replacement part if you use them after the original bumper mounts fail, not if you use them as a matter of convenience.


If I understand your question correctly, you have some sort of device that goes between your bumper and the rest of the robot. You could connect and disconnect only the bumpers themselves from this device, and leave it permanantly attached to the frame. But for simplicity, you have constructed two of these devices and would leave the two colors of bumper sets connected to their respective devices.

I would think this falls under <R13>:

<R13> When determining weight, the basic ROBOT structure and all elements of all additional mechanisms that might be used in different configurations of the ROBOT shall be weighed together. Included in the weight limit are the robot control system, decorations, and all other attached parts.
Example: A team has decided to design their ROBOT such that, before any given MATCH, they may change the configuration of the ROBOT based on perceived strengths or weaknesses of an opponent. The team accomplished this by constructing a basic drive train platform plus two versions of a GAME PIECE manipulator, each manipulator being a quick attach / detach device such that either one or the other (but not both) may be part of the ROBOT at the beginning of a MATCH. Their ROBOT platform weighs 107 lb, version A of the manipulator weighs 6 lb, and version B weighs 8 lb. Although only one version will be on the ROBOT during a MATCH, both manipulators (and all components of the manipulators that would be used during the MATCH) must be on the scale along with the ROBOT platform during weigh in. This would result in a rejection of the ROBOT because its total weight comes to 121 lb.

It sounds like your devices are two separate pieces, only one of which can be installed on your robot at any given time (like the two separate manipulators in the rule example). You would count the weight of both pieces in your total robot weight.

<R07 D> also seems relevant, at least to me, prohibiting that configuration. But, that’s just my opinion, which is worthless at any competition.

There is no simple answer to this question. If the bumper design seems to include significant robot structure and it appears you are shifting weight that should be included with the robot then the weight cannot legally be included with the bumper. If the structure is to make it easy to attach the bumper then the weight can be included in the bumper weight. Each complete bumper set must be less than 20 pounds. It should be apparent to the inspector that the design is not trying to reduce the weight of the robot by shifting structure to the bumpers. Each design is different and no definitive answer can be given on these multitude designs. Please review the bumper rules and as a reminder, bumpers must conform to rule R07 in it’s entirety not just some of it’s parts.

Al, to avoid confusion, shouldn’t that read "each set of bumpers must be less than 20 pounds?

Edited, thanks.