section 6.2.3 states that there is a bump in the floor due to the plates in the center. how big exactly are those plates going to be? does this mean that if we drive along the inner path we need to accomodate bump but if we take the outer we dont? also will the edges of this bump be vertical or filleted? im just asking because a vertical bump like that would totally sheer off the plastic sleds we were thinking of using.
The plates are drawn in the field drawings and are rather long and wide. (Check for the drawings on the FIRST website.) The plates are then in turn, covered with a piece of carpet and the edges of the carpet are then taped with gaffer’s tape to the playing field carpet. There are no fillets on the plate edges. If you are using skids, your design needs to accomodate these “bumps”.
Try the Q&A area of forums.usfirst.org:
http://forums.usfirst.org/showthread.php?t=8277
I’ll grant you that their drawings are a bear to get thru, but once you get the hang of their referencing (which I still can’t quite understand) you’ll see drawing G08-0003 sheet 1 of nothing references the three plates in question, number 01, 09, and 10. The chart in the upper right sends you to the detail drawings. On drawing G08-0004 sheet 2 of 19 that the Center Base Plate sticks out 24 inches from the centerline of the center wall, and is 46.5 inches wide. The Divider Mid Base Plate is 24 inches wide (sheet 8) and Divider End Base Plate is 30 wide (sheet 9) and sticks out 6 inches the other way from the centerline of the end vertical pipe. They are all 1/4 inch aluminum plate. (Sorry, I had to do this just to see if I could find the info.) And on preview, I see Al snuck in an answer.
Yet, I still can’t find how long the center wall might be, or how much clearance there is from its end to the alliance wall. Go figure.
On http://www2.usfirst.org/2008comp/Drawings/2008%20Field/2008%20Arena_Layout_and_Marking.pdf
You will see that there are 5 plates and a rough idea of their intrusion into the playing field. As Roger has pointed out it is a little difficult to get through the drawings. The “Basic Field Drawings” are the field borders that are used from year to year with the changes for this year’s game.
The middle part is 32" long, the 4 tubes are about 60" long, there are 8 slip fittings that are 6" long, so it’s about 32" + 240" + 42" = 314" long, or about 26 feet. that would leave 54 - 26 = 28 feet for both ends combined, divide in half is 14 feet between the end of the divider and the alliance wall. I fudged the numbers some, I think I made it too short, so my guess is that the distance from the end of the divider to the alliance wall is supposed to be the same as the distance from the divider to the outside wall along the straightaways, about 13.5 feet.
Thanks, squirrel. I suppose I’ve could have added it all up too, but following their exploded overall drawing and searching for all the details made my head ache. I just scaled the plan and the dimensions and ratio’d them and got two different answers – either about an inch below or above 13.5 ft, so I guess you are correct. Or me. 
Not that it really matters – our room is 7 inches too short, and 1 or 2 feet too narrow. So be careful on your driving 'round those turns!
The official answer is probably “it depends on field conditions.” If I ever left a dimension like that off a construction drawing I’d never hear the end of it!
Pics from the Official FIRST Kickoff field in Manchester, NH of the “bumps” you are referring to here:
Well, those photos changes everything. I thought the plates were put down first, then the field carpet on top of the plates. I didn’t know there was another carpet square put on top. Makes sense, I guess, so they can reuse the field carpet from year to year. Now I understand how GDC has it “up to 1/2 inch” thick on a 1/4" plate.
Of course, this makes me a little more nervous about this point I made about the overhead being pulled sideways by a wayward robot. I’m sure between weight and direction of pull the overhead would win, but having it only held down by carpet squares and gaffers tape I wouldn’t be so sure.
Roger,
The carpet gets very beat up during a full weekend of competition. The plates are applied to the playing field carpet with a velcro strip around the perimeter of the plate and down the center line. This bonds very well with the carpet and since it is on top of the applied carpet will not damage the floor underneath.