3019's preview of our "black knight"

we are getting there At least it looks nice. We have a pretty consistent shooter. More features are still to come

Are those bumpers 8 inches off of every corner? From the view it looks like the are shorter than that. Just want to check so you don’t have a rude awakening at inspection.

We found with too much compression those bag motors will stall so be careful.

The front side does not actually have 8 inches of frame, so due to robot rules we only need that amount of coverage. We looked in the Q and A and they kept referring to the same rule about if a side is shorter then 6 inches

You are incorrectly interpreting the bumper rules. As stated in the manual, if you were to wrap a string around your robot, your frame perimeter would be the polygon created by that string. Regardless of whether or not an actual frame member is present across the entirety of the front of your robot, that line is your frame perimeter. Since that side of your frame perimeter is >8", you need at least 8" of coverage from each corner.

That’s not how the 6 inch rules work think. See section 4.7; right under R19 there are four diagrams showing possible bumper configurations. The lower-left image shows your predicament clearly- you’ll need to add more bumper on that side.

[R2]'s blue box describes a “string” test that will define your frame perimeter. All of [R19] is in reference to this frame perimeter and not the actual robot frame. That the frame is only 6" wide around your front wheels doesn’t have anything to do with how the frame perimeter is defined. I encourage you to seek out further advice before moving forward with 6" of covered frame perimeter corners.

It looks like an extremely easy fix though, given a great and simple design.

I believe you are confused about the rule. The 6" rule is if the entire side of the frame is less than 8"… not just pieces of it. So if you had a robot that was 7" side (total) by 48" long… you could then get away without 8" of bumper on the 7" sides. Your robot is well over 8" wide in the front and back and will need to have at least 8" of bumper/support to pass inspection.

What everyone else said about having at least 8" of bumper. But also remember that you can’t just make your bumpers 8" long. The end will also have to be supported by frame, so you’ll need to extend the frame of your robot to 8" in those locations as well.

The outside edge of your rhino track is defined as a corner. The rule states you need 8 inches of bumper extending out from every corner.

The 6 inch rule is for if you have a robot shaped like thishttp://blogs.solidworks.com/teacher/2014/03/spartan-robotics-frc-team-971-share-their-story-from-sacramento-regional.html scroll a few paragraphs down to the picture without the bumper. They have a side of frame less than 8 inches, so they only need 6 inches of bumper, but then they also have 8 additional inches of bumper off of each corner.

You also might consider having more than one CIM per drive train side.

Looks really nice-- hopefully it will be as fun to watch as it is to look at!

Wow…geez im just the media guy this year (kidding but not…) I actually just looked over the rules and will have to inform my team of this unfortunate mistake we made. In the beginning of the season they did keep saying that if a side was shorter then 8 inches it just has to be covered…I looked at the q and a and the updated manual again…Definitely not one of the rules that should have been vague…

I am interested how some teams did solve the problem?

Also remember that it is 8" of frame length from the corner that has to be covered, not the outside measurement of the bumper itself, which will be longer since it has to go past the corner to mate up with the adjoining side bumper. The corners at the back of the image do not look to be covering 8" in either direction down the frame from the corner. The close ones could also be too short down the sides but not sure. Perspective of the image is making it a little tough to tell.

We made a 30" wide robot and raised the bumpers so that we could get up onto the batter, as well as have a 13.5" cutout (1/2" of leeway).

We’ve accumulated 6 pages of bumper rules in the manual. Trust me; yours isn’t the only team to have made a mistake with bumpers. It’s happened before, it’s happening right now, it’ll happen in the future. I dream of a day that a first week event can get through inspection day without any bumper violations, but I kind of doubt that’s going to happen anytime soon.

I guess we can’t blame FIRST for the crazy bumper rules though. At least half are there to eliminate loop holes and sneaky optimizations teams have come up with over the years.

You’re just having flashbacks to last year.

Any ways, Thank you to everybody for pointoing out this BEFORE we got to bag n tag or even competition. I remeasured the bumpers today and told my team, as disheartened as we are its good to know sooner then later. It turns out almost all our bumpers are wrong…lol, look forward to the entire robot reveal! with legal bumpers!

First off, glad this got caught in time. Second, thank you for taking it so well and not arguing with everyone about it. It is an honest mistake in reading the rules and you are not the first team to make it.

For our team we have a mostly sheet metal robot, and the front brackets got bent wrong and ended up 7.75 inches. :-(. we ended up cutting out 1/4 inch polycarb and adding it to the end of the plate making it 8 inches long.

I hope you guys can find a similar solution.

Best of luck,


Glad that you are going to get this corrected before the inspectors had to give you the bad news. As a former inspector, I HATED having to tell teams that they need to rebuild the bumpers (how many teams actually bring supplies to rebuild them?).

I am looking forward to seeing your bot at both Arizona Regionals (I’ll be the guy scrambling around making sure you are connected to the field)