Fasteners and Frame Perimeter


#1

R1 states that “Minor protrusions no greater than ¼ in. (~6 mm) such as bolt heads, fastener ends, weld beads, and rivets are not considered part of the FRAME PERIMETER.” I realize that minor protrusions are up to the inspectors discretion, however I do have several questions. Would a thin 1/2 inch hex collar on protruding shaft likely pass inspection? And would fasteners attached to articulated elements above, but in line with the frame perimeter pass inspection? Lastly, I don’t see the same protrusion exception counted for the height, am I right that bolt heads above the four foot mark won’t pass inspection?


#2

On the first, as long as the total height of the shaft collar plus any space between the collar and the FP (including spare bits of shaft and bearings) was no greater than 1/4", I don’t see any reason why not. The KoP chassis has a 1-1/8" diameter bearing which protrudes from the FP, and I haven’t seen or heard of anyone failing for that.

I can’t be 100% certain on fasteners on articulated elements above the FP. I have seen fasteners above the bumper zone but on fixed frame elements pass.


#3

My reading of R2

In the STARTING CONFIGURATION…no part of the ROBOT shall extend outside the vertical projection of the FRAME
PERIMETER, with the exception of…minor protrusions such as bolt heads,
fastener ends, rivets, cable ties, etc.

Seems to imply that all parts of the robot are allowed the same minor protrusions, but I would like to emphasize the last part of the blue box for that rule

The allowance for minor protrusions in R2 is intended to allow protrusions that are both
minor in extension from the FRAME PERIMETER and cross sectional area.

The cross sectional area of any protrusions should be small, lest they invite scrutiny on the inspectors behalf


#4

Take note of this though. The thin VexPro shaft collars are 1/4" themselves. If you have any additional bearing flange, shaft protruding out of the collar, or anything else, you’ll be over the limit. You don’t want to have to redo your frame during practice time in order to pass inspection. There’s still enough time in the season to adjust your design. Perhaps replace the shaft collar with a tapped hole and washer in the shaft.


#5

There is no “minor protrusions” exception for height. So keep it all below 48" during starting configuration.


#6

Not this years KOP if you build it as suggested (side rails flipped) for the new bumper mounts. Beyond the bumper mounts, in puts all the fastener heads in the trough of the channel.

Picture the FRAME PERIMETER defining a box, extending up to the max height of the STARTING CONFIG. The 1/4" minor protrusions for fasteners applies all the way up. However, as per R1, this applies to “fixed, non-articulated structural elements of the ROBOT”. R2 covers off other parts (MECHANISMS) and while it does allow for “minor protrusions” it does not specify an measurement. Given R1, I would not suggest having protrusions greater than 1/4", and ideally have none.

As some else already noted there is no exceptions to the STARTING CONFIG height rule.