Re: Is this legal (Bumpers)?
 

Ahh, i understand your concern now. As it turns out, we have a little, but probably not enough, backing to the bumpers outside of the basic kit-bot frame. The wheel mounts, for example, provide some of that support, but only on the lower half - and currently we don't have anything supporting it above the center line.

We are planning on making some "roll bars" to go over the top of the robot, and those could supply some of the structure you indicate. Would you recommend having a horizontal bar along the top/bottom of the bumper for the full length of the bumper, or would some vertical supports (spaced maybe a foot apart, used as part of the roll bars and thus reinforced to take the impacts) be sufficient?

I don't think anyone on our team has considered these types of off-centered impacts, thanks for bringing it up.

~Jon

Re: Is this legal (Bumpers)?
 

Jon,
As you pointed out in your previous post...

<R07> M - specifically the statement that the bumper has to be supported along its full length.

This is the rule your inspector will be confirming during inspection.

Re: Is this legal (Bumpers)?
 

Jon,

May I suggest you consider the attached image. In addition to providing increased vertical support, it removes any ambiguity as to where your frame perimeter is defined.

Regards,

Mike

Re: Is this legal (Bumpers)?
 

Mike,
I am not sure that even that implementation can handle the contact we will experience.

Re: Is this legal (Bumpers)?
 

Al,
Your posts are making me slightly nervous. I understand this game will result in some impacts we are not used to seeing in FIRST. However, it seems that in your interpretation (being an inspector, and a great inspector at that ;) ) is almost any implementation of a single beam along the back of a bumper will not be robust enough. Now in your opinion would you approve the 2 previous design/sketches posted in this thread for inspection?

-Brando

Re: Is this legal (Bumpers)?
 

Brandon,
As Mike Betts has pointed out, the drawing on this page does fulfill the rule of a "fully supported along it's length by robot structure". With the hits we will experience, damage to the bumper and robot could be minimized with a better support behind the bumper. A team needs to consider the risk of having a bumper dislodged, broken off or a robot damaged in the design of the entire robot. If you are asking "Is it legal?" the answer would seem to be yes. (based on drawing only) If you are asking "would you do something different?" then yes I would back it up with more frame structure.

Re: Is this legal (Bumpers)?
 

I was asking both those questions. Thanks for answering.

Re: Is this legal (Bumpers)?
 

Understood... the kit-bot frame would still be supporting it along the entire length, several vertical projections would be placed as supplementary supports to prevent the bumpers from twisting on that frame and possibly pulling the bolts out of the plywood. Since a picture says a thousand words, take the attached image, showing views of the sides and front/back surfaces of the robot. All parts shown are intended to be flush with the frame perimeter (the kit-bot chassis running through the middle), and can be assumed to be sufficiently supported to be considered structural members.

With this design, the bumper is supported along its full length through the kit-bot frame, with vertical projections designed to provide additional support for the type of impacts you've brought to our attention. The top and bottom sections of the bumper are not supported for the full length, but supports are placed roughly every foot to help absorb the impact and to prevent the bumper from twisting and putting extreme stress on the attachment points going through the kit-bot frame, as indicated in the previous pictures.

So i guess the question is - does "being supported along its full length" include top and bottom members that traverse the full length, or would something similar to this be sufficient?

Re: Is this legal (Bumpers)?
 

That's the design of the AndyMark bumper kits.

Re: Is this legal (Bumpers)?
 

Brandon, et al,

The inspectors will inspect for safety and adherence to the rules. Al's very sound advise goes further in getting you to consider more failure modes.

Just realize that, with the exception of safety concerns and rule violations, the inspectors will approve designs and implementations that, in our opinion, are likely to fail.

We may make suggestions on forums or at events based on our experience that are optional for the teams.

We really want all the teams to succeed and the students to have a memorable experience.

Whether those memories are good or bad will depend on many factors...

Regards,

Mike

Re: Is this legal (Bumpers)?
 

Thanks Mike. The goal of my question was to clarify if Al thought the design was illegal, or not robust enough. Obviously in the example you posted (the andymark mounting style) there could be more done to stabilize those bumpers. However, is it necessary would be the question I have to ask. Thanks for helping to clarify.

-Brando

Re: Is this legal (Bumpers)?
 

Is anyone else considering bumpers at differing heights on the several sides of their robot? All bumpers still within the zone of course; there is a whole inch of room for deployment. We're thinking of maximum height for the kicker's end and minimum height on the other three sides.

Re: Is this legal (Bumpers)?
 

Wildstang is, and it is in fact legal. Q&A ruled on that yesterday.

Re: Is this legal (Bumpers)?
 

I'm just wondering about the corners where the elevation difference will happen. It's only an inch, but which side should get the cushion extension into the corner. Also wondering if the whole corner should be filled at 6" total.

Re: Is this legal (Bumpers)?
 

We are?

Bill,
All other rules still apply. No hard parts in the corners. A 1 inch difference is not going to make the design less successful nor fail to pass inspection per the Q&A.