Bumper Length Rules (Another One)...

First, let me apologize for another bumper post. I know there are tons being posted all season, but the rules for bumpers are truly unclear, and my team needs to be 101% sure that our robot is non-compliant before starting a major redesign (at the end of Week 5) :mad: :mad: :mad:

So, the original rule R19 states " If a side is shorter than 8 inches, then the entire side must be protected by BUMPER". See figure 4-3.

In update 5 to the rule book issued on Jan 26, the updated figure 4-3 has three arrows to the figure now instead of two. The middle arrow looks like it is stating that a side less than 8 inches is no longer acceptable? Is this correct?

Your side is not 4 inches in the picture its from #4 on your tape measure all the way to the other side of your robot way over on the left. You need 8 inches of bumper on each corner. You will need 4 more inches of bumper and frame on each side to be compliant.

The side of your robot is greater than 8". When measuring for sides, if you put a string around your robot, that determines your sides and perimeter. Since from corner to corner, that is larger than 8", you need at least 8" on each corner. Hopefully this makes sense.

To summarize and to try to help…for your bot (as for best guess from your picture)

Each front corner will need an 8" bumper side. In other words, The front of your bot will have to have 16" of bumpers with 8" per corner.

The issue you will run into based on what I see, is that the shooter will very likely, hit the bumper as it raises and lowers. So take that into account as I don’t see it working as configured in pic. You may have to make your bot wider (or add 4"+ mounting extensions on side) to avoid the shooter hitting your front bumper or you may have to move your shooter forward so wheels are past the front bumper up to 15" forward of frame perimeter.

There is no way around the 8" per corner of bumper in your case based on what I see.

Hope that helps.

Let’s see if this makes it any clearer. Take a long piece of string (actually, surgical tubing might be better) and wrap it around your frame, pulling tight. From each corner formed in that string, measure 8". Mark the frame in that location. Can’t mark the frame, because it isn’t there? You’ll need to put something there. By the way, that string is the frame perimeter.

Any side of the frame perimeter that is <16" between corners will need bumper along its entire length due to the required 8" of bumper from each corner.

Not to me.

Anyway, your FRAME PERIMETER looks to be about 28 inches (not 4) on the side facing the camera.

Use the string mentioned above to find the FRAME PERIMETER, which is not in any way related to your actual metal frame (aside from both being on your robot). Be sure to do this in your BUMPER ZONE, btw.

Why do I put some words in UPPERCASE? These are specifically defined things…read the rules to see what they mean. If you don’t, then I agree things may be unclear to you. ::rtm::

Bumper Length stuff may have been changed, Click here for team updates.

The Team Updates have been clarifying the the bumper rules. The fundamental principles upon which these rules are based on have not been changed by the updates. Unfortunately, I don’t believe that the updates magically makes the OP’s bumpers (and those of quite a few other teams) legal.


Others have been pretty clear but let me confirm your robot is illegal unless you put 8" of bumper in each corner. There is no gray area.

If the string you wrap around your robot is longer on a side than 8" than you need to have at least 8" on either corner.

So if your side is shorter than 16" then that side needs all bumper.

Sorry but it looks like you need a redesign.

One last thing: the plywood part of the bumper needs to be at least 8".


“Side” is defined… Those pieces in the front of this robot are not sides…
they are parts of a side. Each must be 8" wide…

Just to be exceedingly specific:

The plywood part needs to be at least 8 inches from the corner of the FRAME PERIMETER. As an inspector, I have often come across robots with 8 inches of plywood, but 3/4" overlapping in one corner. This overlap causing one side to be only 7 1/4" and thus illegal.

There may be some methods that will likely be less painful for your redesign should you be interested in entertaining them. If you have some extra inches of frame perimeter, there are some methods you can do to reduce the impact on your intake.

For the record, I am not sure who it is in the picture, but I am very familiar with that look. It is the “Now what do we do” look which often occurs when things get real in week 5.

The great news for you is… Its week 5, you still have a good chunk of time to deal with this issue and make corrections. As an LRI, I have seen this bad of an issue hours before competition was to start, and the team came through and still had a good weekend. Take a deep breath, a hard gulp, and start the work to fix it. Spend 30 minutes and brainstorm all the ways you can “correct” it, and discuss the pros and cons of each, pick a direction and get to it.