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

[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.

[Chris is me]

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.

But this isn't true - there are allotments for bumpers going over various sized gaps in the perimeter.

[Al Skierkiewicz]

OK Ladies and gentlemen,
Time to quote the rules from Section 01 Introduction...
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.

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.

This kind of says it all. Language similar to this was the rule last year as well. Hold a string around the frame and that describes the FRAME PERIMETER. The FRAME PERIMETER must be protected by bumpers and this year the rule under Section 04-The Robot R07-K allows some leeway that was not present last year, i.e.some gaps and some unsupported bumpers. The "T" robot last year and "hourglass" robot shown above fall under the same rule. A string wrapped around the robot at the height of the bumper zone would bridge the opening and therefore require bumpers attached to the robot everywhere the string exists. I failed a "T" design last year for the violation. I explained the rule and assisted the team in becoming compliant. As they were under size and underweight and had time to complete the needed mods, they played. In light of other game rules, (cough herding cough) it is easy to see why the FRAME PERIMETER is so defined.

[Mr.G]

It doesn't say the string has to be taught.....You could pull the string around the robot much like a seamstress would use a measuring tape to measure in their job. I took the string as more like a level line.

It is the exterior vertices part that means you can't have inside corners.

Not to argue this anymore, but this is just a badly written rule. It would be much better to just say "inside corners are not allowed"

Originally Posted by Al Skierkiewicz

A string wrapped around the robot at the height of the bumper zone would bridge the opening and therefore require bumpers attached to the robot everywhere the string exists. I failed a "T" design last year for the violation. I explained the rule and assisted the team in becoming compliant. As they were under size and underweight and had time to complete the needed mods, they played. In light of other game rules, (cough herding cough) it is easy to see why the FRAME PERIMETER is so defined.

[Molten]

Originally Posted by Mr.G

It doesn't say the string has to be taught.....You could pull the string around the robot much like a seamstress would use a measuring tape to measure in their job. I took the string as more like a level line.

It is the exterior vertices part that means you can't have inside corners.

Not to argue this anymore, but this is just a badly written rule. It would be much better to just say "inside corners are not allowed"

I disagree with the phrase of "inside corners" as I had to read a fair amount on this thread to know what that means. However, adding the word taught would be a much better solution.

[Al Skierkiewicz]

Kevin,
Not to be hard on this but it doesn't say "wrap the string around your frame and push it in where ever the frame goes in". It simply says "wrap the string around... ". The above rule is specific to 2011 only and does not allow for interior corners. If the GDC changes the interpretation, I will inspect for that new definition.

[Mr.G]

Definition of wrap

wrap verb
a : to cover especially by winding or folding
b : to envelop and secure for transportation or storage : bundle
c : enfold, embrace
d : to coil, fold, draw, or twine (as string or cloth) around something

Al, I am just having fun now, but I disagree per the above definition. When "wrapping" an oddly shaped present you would cover each segment as I have stated for placing the string around the robot.

Cheers.

Originally Posted by Al Skierkiewicz

Kevin,
Not to be hard on this but it doesn't say "wrap the string around your frame and push it in where ever the frame goes in". It simply says "wrap the string around... ". The above rule is specific to 2011 only and does not allow for interior corners. If the GDC changes the interpretation, I will inspect for that new definition.

[Al Skierkiewicz]

Kevin,
Good thing I am in a good mood today.
Good Luck!
Al

[Andrew Schreiber]

Originally Posted by Mr.G

Definition of wrap

wrap verb
a : to cover especially by winding or folding
b : to envelop and secure for transportation or storage : bundle
c : enfold, embrace
d : to coil, fold, draw, or twine (as string or cloth) around something

Al, I am just having fun now, but I disagree per the above definition. When "wrapping" an oddly shaped present you would cover each segment as I have stated for placing the string around the robot.

Cheers.

Except that paper would not be touching the interior vertices. Instead it would be touching the outside vertices of the concave polygon. Any frame that is a concave polygon is illegal because all of the vertices on the polygon are not touched when you wrap a string around the bumper perimeter. I don't like the rule but I also don't like several other rules, doesn't mean I can break them.

If you want to align yourself consider making an asymmetrical frame and deploying a single bar out. That way half your force is taken by the bumpers. Alternately if you are just worried about another robot ramming it you can place it up in the air and only deploy it when you are going to score. Or you can just build it strong enough to take hit... you know, like we had to do back in the day when we didn't have these fancy bumper things.