pic: Legal Frame ????????????????

[joeweber]

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[thefro526]

I would ask the Q and A for an official ruling, but my understanding is that the bumper perimeter has to be a convex polygon as defined by the definition of frame perimeter:

Originally Posted by Section 1 of Manual

FRAME PERIMETER – the polygon defined by the outer-most set of exterior vertices on the HOSTBOT
(without the BUMPERS attached) that are within the BUMPER ZONE.

[alectronic]

This has come up in past years and was not allowed, but you could always try running it past the Q&A again.

This is kind of on that same track:
http://forums.usfirst.org/showthread.php?t=15188

[Chris is me]

If that "T" had any concave areas, it shouldn't have passed inspection.

This looks illegal. A FRAME PERIMETER cannot be concave (barring the allotted cutouts)

[alectronic]

You are correct Chris, and in the FIRST Forums thread there they talk about how it should not have passed.

[jethrow]

i would say yes as long as the bumpers are ok.

[MrForbes]

Originally Posted by jethrow

i would say yes as long as the bumpers are ok.

Then you might want to spend some time reading the robot rules. Specifically, see Section 1 of the Game Manual, read the definition of FRAME PERIMETER. Also study section 4, specifically the information about bumpers.

http://usfirst.org/roboticsprograms/...nt.aspx?id=452

[Vikesrock]

Originally Posted by jethrow

i would say yes as long as the bumpers are ok.

That's very interesting considering your signature. The FRAME PERIMETER of this frame would be a rectangle with the 4 outermost vertices as corners. The bumpers need to be placed along this FRAME PERIMETER with the maximum unsupported distance being 8".

[Mr.G]

We were the team that had the tee design last year and won an award for it at our first event. At the first event the ref's questioned the design but concluded that they couldn't see that it was positively in violation of any rule. But asked if we would ask the GDC to verify and we did here: http://forums.usfirst.org/showthread.php?t=15188 As you can see they never responded even after many phone calls. We showed up at our second event and they told us we couldn't compete. We could have fixed it in the fix it window if they had responded. But instead were forced to fix it at the event. Redoing the frame and bumpers was not easy.

The whole thing was handled very badly with FIRST. I was very sad to see the rule in the rule book again this year. It is a very confusing rule that really should just say "no inside corners are allowed"

After much arguing at the event they finally told us what part we were in violation of. They interpret it as: The outer-most exterior vertices (aka corners) are the perimeter. Thus if you have an inside corner it is not outer-most and thus is not allowed.

They tell us not to lawyer the rules but then they don't write them like an engineer would and it forces us to lawyer them.

Here are this years rules:
BUMPER PERIMETER – the polygon defined by the outer-most set of exterior vertices of the BUMPERS when they are attached to the HOSTBOT. (To identify the BUMPER PERIMETER, wrap a string around the BUMPERS at the level of the BUMPER ZONE - the string describes the polygon.)

FRAME PERIMETER – the polygon defined by the outer-most set of exterior vertices on the HOSTBOT (without the BUMPERS attached) that are within the BUMPER ZONE.

In blue: To determine the FRAME PERIMETER, wrap a piece of string around the HOSTBOT at the level of the BUMPER ZONE - the string describes this polygon. Note: to permit a simplified definition of the FRAME PERIMETER and encourage a tight, robust connection between the BUMPERS and the FRAME PERIMETER, minor protrusions such as bolt heads, fastener ends, rivets, etc are excluded from the determination of the FRAME PERIMETER.

[MrForbes]

I'm an engineer, when I read the rules it's easy for me to understand that they mean "no inside corners".

If you're not an engineer, yeah, I can see how it could be confusing. Although it was discussed to death here on CD....

[joeweber]

Apparently it is better to not have a concave bumper system than to have an aluminum mechanism drop down after start to give the same desired contact design. That will mean other robot will be running into our mechanism through the match and the bumper behind it will be just for looks and rules

[ptan]

We had already asked the GDC about this design (yes, we thought of doing it as well). The answer was no.

http://forums.usfirst.org/showthread.php?t=16259

[Sunshine]

Originally Posted by joeweber

Apparently it is better to not have a concave bumper system than to have an aluminum mechanism drop down after start to give the same desired contact design. That will mean other robot will be running into our mechanism through the match and the bumper behind it will be just for looks and rules

Totally agree

[jimsmith2354]

Originally Posted by squirrel

I'm an engineer, when I read the rules it's easy for me to understand that they mean "no inside corners".

If you're not an engineer, yeah, I can see how it could be confusing. Although it was discussed to death here on CD....

I have been an engineer for over 30 years, and in Section 4, I see the definition of a perimeter. It would have been much clearer just to add that the bumpers must continuously touch this perimeter. Hopefully we will see this in an update, as I suspect many teams would like to use the "V" design in the original post to help center the robot on the tower base. The people at FIRST have a tough job in writing rules, but not giving any hints or design directions.
Jim

[maltz1881]

Originally Posted by jimsmith2354

I have been an engineer for over 30 years, and in Section 4, I see the definition of a perimeter. It would have been much clearer just to add that the bumpers must continuously touch this perimeter. Hopefully we will see this in an update, as I suspect many teams would like to use the "V" design in the original post to help center the robot on the tower base. The people at FIRST have a tough job in writing rules, but not giving any hints or design directions.
Jim

They turned us down. We figured it was a 50/50 chance. I have to give the people of FIRST a lot of credit for giving us the answer on a Sunday. That was the point of the "V" to line up at the pole. One of the kids already have something up their sleeve to solve it!!

The same way teams get rewarded after posting how they design their robot, send the plans to their sponsor, and recieve a kit back with all the parts cut, brackets bent and metal skins laser cut. A simple bolt together and they are hard to compete with.

I say more power to them!! Last year we had 2 engineering students on the team ( still do) and we won the Excellence in Engineering Award at both districts we went to. Again it is because we have crazy imaginations that we encourge in the garage. We make our parts ourselves and we don't have ANY fancy machines and our budget is right around $1,200 for the year. ANYTHING is possible.