Chief Delphi - The arena

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When they say "The rungs are located 30 in., 60 in., and 90 in. off of the floor."
do they mean the middle of the rung is located at 30in above the floor ? or the top part or the bottom part ?

From the drawing of the pyramid in the game manual, it appears 30" is the middle of the bar. However I can't find a written clarification of that.
Does anyone who has built their own pyramid know where 30" sits relative to the bar?

It's the middle. See the attachment for the full mathematical details.

All dimensions are from 2013_Game_Specific_Drawings.pdf, parts GE-13022 and GE-13024.

I believe it is 30 inches from the floor to the middle of the lowest rung.

To extend this question. Where is the 30 inches measured from? Is the 30 inches measured from the level at the center of the field (where the carpet is not raised up), the top of the carpet that covers the raised portion of the floor protector that the pyramid sits on, or the carpet that covers the top of the pyramid base plate?

Thanks very much dcarr. Looking closely at the CAD of the pyramid, it is clearly 30 inches from the centre of the low rung to the bottom of the steel plate at the base of the leg.
It is my understanding from the game manual that plate is velcroed directly to the level of carpet that covers the entire field.

Quote:

Originally Posted by Nadav (Post 1217788)

When they say "The rungs are located 30 in., 60 in., and 90 in. off of the floor."
do they mean the middle of the rung is located at 30in above the floor ? or the top part or the bottom part ?

It's to the top of the bar.

I wonder how far off the real pyramids will be, compared to what we think they'll be? I think it might be wise to build the robot so if it's off by an inch or so up or down, your robot will still work.

Quote:

Originally Posted by MrForbes (Post 1221117)

If your robot has a tolerance of less than an inch for climbing, then you've got other problems besides the pyramid...

Quote:

Originally Posted by Game Manual Section 2.1

The competition ARENA is a modular construction that is assembled, used, disassembled, and shipped many times during the competition season. It may undergo wear and tear. The ARENA is designed to withstand rigorous play and frequent shipping, and every effort is made to ensure that the ARENAS are consistent from event to event. However, as the ARENA is assembled in different venues by different event staff, some small variations do occur. Fit and tolerance on large assemblies (e.g. the LOW GOALS) are ensured only to within ¼ in. Overall gross dimensions of the entire FIELD may vary up to 4 in. Successful teams will design ROBOTS that are insensitive to these variations.

Emphasis mine.
I imagine that the Pyramid would fall under a large assembly, though for such an important game piece I wouldn't be surprised if it's even more precise than .25". A quarter inch over ten feet is a lot of variance...

Quote:

Originally Posted by CalTran (Post 1221122)

If your robot has a tolerance of less than an inch for climbing, then you've got other problems besides the pyramid...

Climbing is not the only use for the pyramid.

Quote:

Originally Posted by MrForbes (Post 1221124)

Climbing is not the only use for the pyramid.

Shooting through the rungs?

Quote:

Originally Posted by MrForbes (Post 1221117)

I think it might be wise to build the robot so if it's off by an inch or so up or down, your robot will still work.

Definitely agree!

The bottom rung height is important to know if you plan on driving under the pyramid. I can see teams designing their robots to barely be able to drive under the bottom rung and then arrive at competition to find out they are a half inch to tall.