Shelves

[punky2k1]

My team was wondering what the shelves were made of. Please name the material, wire mesh, plywood, etc.

[jrukes]

You can find the exact description of the shelf material on the thread by Mike Martus titled "Field Pictures are posted".

-Jason

[kmcclary]

All right! With all the questions I've already asked on THAT subject, *I* can probably finally answer one!! <grin> (Disclaimer: I am not "official", but can summarize the other posts here with the best of them... :-)

Summary:

The shelf itself is a ClosetMaid 16 inch deep "SuperSlide" shelf. It is a white plastic coated "wire mesh" modular closet shelf, and looks like a flat wire grid panel, with a drop lip on the front.

There are pictures of the shelves in the PICTURES area at:
http://www.chiefdelphi.com/forums/pi...DESC&sort=date

I've found the shelving is available in at *least* 4' and 12' lengths, if not others. The 4' length at Home Depot is:
16"x4' SuperSlide Linen Shelf
Brand: ClosetMaid
SKU #873535 $4.69 each

I'm not sure if HD carries the 12' length. Our local hardware store had the longer one, so we went with that.

Experience: If you have room, I'd definitely advise getting a 12' section, vs a 4' one. With four vertical boards and three backboards, It'll give you a three shelf assembly *without* messy joints at each divider.

Experience: The backboards are inline with each other. Mount the intermediate backboards to the vertical dividers with L-brackets on the underside of the backboards. This allows for fine adjustments and disassembly, but you won't have hardware interfering with the "game side" of the backboards.

Note that some of the dimensions of the vertical dividers were missing or incorrect in the original rules document. The correct "depth" length for the divider's baseline is *10*, NOT 6 inches. The backboard is a 47" long 1x6. The corrected shelf diagram is at:
http://www.chiefdelphi.com/forums/at...s=&postid=7993

Note that the backboard's position is STILL not specified in the new document. I found it is claimed to be located along a line drawn between the top back (upper left) corner of the diagram and the back edge of the shelf, with an unspecified gap that *should* work out to be somewhere around 4" set between the lower edge of the backboard and the shelf. ("Wide enough to be a significant gap, but just tight enough to not let the jug drop through...")

Does all this sound about right, Mike? <grin>

Hope this helps!
- Keith McClary, Huron High Rookie Team 830

[meaubry]

Keith,
I crown you the shelf expert ... insert sound something like "dut dutta da" And, furthermore, I am amazed at your summary skills (grin) I thought summarys were suppose to be short little snippets (sp?) though - anyways, well done Keith!

[Mike Martus]

The juice jugs will not fall through. That has been tested.

Boards are mounted on angle alum, fastened to both boards.

The boards align with the shelf lip using alignment with back flush of the board to the forward imanagery line to the shelf.

Hey, if you are designing your machine that precise, well good luck.

Remember everything is relative and the game was designed to allow many scoring places. Who know what is safe? Will the juice containers stay on the shelf? We will see!

I think the exact angle is not critical, however I will send a student with a protractor to get a measurement (guess).

[kmcclary]

"Shelf Expert", eh??? <LOL!> Just don't expect me to go squat on one of those little things in full lotus position and hum... <wink>

> [I thought summaries were short snippets]

<chuckle> Summaries are simply *complete* sets of data. Hey, Can *I* help it if the data was scattered all over?? <grin> I just didn't want another team to have to scratch their head as much as I scratched mine. (That 6 vs 10 inch misprint REALLY drove me nuts for a while! :-)

> I think the exact angle is not critical, however I will send a student with a protractor to get a measurement (guess).

Don't bother. You're right, that isn't the important number. Besides, we KNOW the angle. It's "along a line between the upper back corner and the back edge of the shelf". Good enough.

The angle is not the problem. What IS important (and we still don't have a real number for) is the TRUE GAP SIZE between the bottom of the backboard and the back of the shelf. Simply measure THAT along that same line as the board lies and we're done!

> Hey, if you are designing your machine that precise, well good luck.

<chuckle> Where that backboard actually lies CAN significantly change the BEHAVIOR of the jug with some widget designs, depending on what you're doing and how you're going to do it.

The gap spec affects more than simply keeping a jug from falling through. It changes the distance of how far the backboard is from the front edge. That IS a rather important dimension, as it affects the REACH specification in EVERY kind of shelf widget design. Make the widget's reach too short and it may not work. Make it too long and you might very well damage the playfield in the heat of battle which we DEFINITELY don't want to do!

Now an inch or so difference SHOULDN'T make a difference in a "tunable" or "compliant" design, but with THIS game, you want a precut K.I.S.S. widget that'll do the right thing every time.

That is why we'd like to know where the board actually is WRT the shelf, so we can make ours match for proper setup, effective practice, and less surprises.

- Keith McClary, Huron High Team 830
--
"The word EXPERT comes from: EX (Has Been) and SPURT (Drip under pressure)"

[meaubry]

Keith,
I appreciate your desire to be as accurate as you can be, but welcome to the world of FIRST, where everything measured has a very large allowable variation (mostly to protect the game developers and field builders) To be honest with you, we have not, and will not build the entire field until Nov. 16th - therefore we are working from bits and pieces that we create to get the basic dimensions from. That's why we have not measured and described every component and field measurement to the level you may want. The backboard was a last second add, on my part to reinforce the structure as I felt the shelves were too weak without it. I rushed the sketch the day before we burned the CD's and didn't catch my error (10" was suppose to be 6") - my bad!
You will soon learn that exact measurements are impossible to give without the responder going way out on a limb. Therefore, the final response to anymore questions about the gap that is created will be "@4" plus or minus 1". Hopefully that will suffice.

[kmcclary]

> Therefore, the final response to any more questions about the gap that is created
> will be "@4" plus or minus 1". Hopefully that will suffice.

That's beautiful, and a good spec. Thank you very much!

Sorry if this was a bother. The spec itself isn't as much of a problem as just having *A* spec. We felt we were trying to design something to handle a moving specification target. We've had to completely revamp our strategy and scrap a machine payload once when the backboard appeared. It made our original design approach totally obsolete. VERY frustrating.

Having a commitment to a standard is actually the most important thing. Spec deviations of 4" are significant in a scale on the order of 1'-3'. That's up to 33%! But ANY number +/- 1 inch at this scale is no sweat. Thank you for deciding on a gap spec.

> The backboard was a last second add, on my part to reinforce the structure
> as I felt the shelves were too weak without it.

REALLY? But that could have been done with braces somewhere BELOW the shelf level, where it wouldn't be involved in the play area. Placing the backboard where you did really DOES affect game strategy.

Fascinating! We thought it was a deliberate redesign of the game in an attempt to eliminate a slew of simple "off the back pushers", because of the rule of "once off the field it is out of play". That could have easily made for a rather boring, low scoring day if everyone's machines concentrated over 90% of their effort on shoving everything out of play, and the entire game came down to only a point or two scored in the goals.

> [...] welcome to the world of FIRST, where everything measured has a very large
> allowable variation (mostly to protect the game developers and field builders)

LOL! I can appreciate that! <grin>

> To be honest with you, we have not, and will not build the entire field until Nov. 16th -
> therefore we are working from bits and pieces that we create to get the basic dimensions from.

Wow... I thought you guys worked all this stuff out MONTHS ago. Boy, that's setting quite a challenge for YOU!

Thanks for putting up with this novice.

- Keith McClary, Huron High Team 830