Bumpers and the Frame Perimeter

[LinuxArchitect]

Your wheels must be inside the robot frame.

[R01-2] The Robot must have a Frame Perimeter that is comprised of fixed, non-articulated structural elements of the Robot.

The bumpers then directly attach to that frame. Standoffs are not allowed.

[R33] Bumpers must be supported by the structure/frame of the Robot (i.e. each end of the Bumper must be rigidly attached to the Frame Perimeter, the gap between the backing material and the frame must not be greater than ¼ in. and no section of Bumper greater than 8 in. may be unsupported).

[GaryVoshol]

Standoffs would be allowed provided they are no more than 8" apart. You can have up to 8" unsupported plywood on the bumper. The ends of each bumper segment must also be supported (they don't want them cracking off).

[Jeff Pahl]

The frame perimeter is defined by wrapping a string around the outermost vertices of your robot. This means you need to have hard corners that stick out farther than your wheels for the string to wrap around. These hard corners will also serve to support the ends of your bumper segments, as required. Then, as mentioned, you have to have structural support standoffs with a spacing of less than 8" between them. They need to be structural enough for the inspectors to believe that there is no risk of them collapsing or causing the bumpers to fail.

For example, it would be hard to convince me that a standoff that was a single 1/4" bolt or rod on an 8" spacing was structural.

So no, your drawing is not legal. You don't have to bring frame out all the way around your wheels, but you have to bring something out at the corners and out past the wheels every 8" to support the bumper. This should not be too big an issue unless you are using 8" or larger wheels.

[Bob Steele]

I would have to respectfully disagree with the idea that the wheels have to be within the frame.

They do have to be within the frame perimeter (which is a fictional line found with a piece of string.)

You could have wheels outside the frame as long as your attachments for the bumpers (which could be place above the wheels or between depending on the wheel size) allow for bumpers that are of the correct height, construction and proper support as detailed in the rules.

The frame perimeter doesn't have to have anything in common with the actual
"frame" of your robot...it usually does but it doesn't have to.
Take a look at the West Coast Drives from the past several years...
the wheels are cantilevered outside the "frame"

I think your drawing is pretty good except that the "string" would mean that the corners of your robot would have to have another "stand off" to support the bumpers there also...

good luck!!

[Tristan Lall]

The disagreement in principle detailed above is simply a reflection of the fact that FIRST has failed to define the frame.

I'm inclined to believe the frame is whatever the team tells me it is, within reason, seeing as it's their design. I'm not too concerned about how structural it is.

(Whether the bumpers are securely fastened to that frame with a tight, robust connection system is a separate issue—there structural integrity might matter.)

[nnfuller]

Can you please quote a rule that says the bumpers must be supported on the corners? I do not see this in the bumpers section. Also, as a good practice, quote rules when asked about legality.

[bhsrobotics1671]

See Team Update on January 17

[R33]
Bumpers must be supported by the structure/frame of the Robot (i.e. each end of the Bumper must be rigidly attached to the Frame Perimeter, the gap between the backing material and the frame must not be greater than ¼ in. and no section of Bumper greater than 8 in. may be unsupported). See Figure 4‑7.

[LinuxArchitect]

Originally Posted by Bob Steele

I would have to respectfully disagree with the idea that the wheels have to be within the frame.

True, you could have the wheels located in the allowed frame gaps. Not sure why such a design would be desired, but who knows.

The wheels only have to be inside of the frame perimeter.