Re: Low Cost Field BOM
 

Grrrrr. I hate it when somebody :caugh:dave:caugh: knows something I don't. 10 ft/sec...

That can't be the max speed of a robot, because you can make a robot go as fast as you like. So there must be something on the field that can achieve a max velocity of 10 ft/sec. Since it is a max velocity, that implies the velocity is not constant. I think Joel is on to something with harmonic motion. Maybe there is a pendulum?

No... this game involves objects dropping from a high elevation. A maximum velocity of 10 m/s would correspond to an object that is in freefall for 0.312 seconds. Corresponding to a height of 1.56 ft. 1.56 ft??

No... clearly that's rediculous. What fun is a 1.56' drop? Maybe there's a ramp that the balls roll down, reaching a maximum VERTICAL velocity at the end of 10 ft/s. Let's say the ramp is at 20 degrees. Then the ball accelerates at sin(20º)*(32 ft/s/s)=10.94 ft/s/s in the direction down the ramp. If the max velocity Dave is talking about is the vertical component, then a ramp height of 4.59' would achieve this velocity. This seems more reasonable. And it corresponds to a ramp length of about 12 ft. Since most of the wood seems to be in lengths of 8 feet, my guess is that the ramp is a bit steeper, say 30º.

My prediction: There are three ramps at 30º on a triangular field up to a central platform (certainty=30%). The central platform can rotate (certainty=20%). There may be some incentive to rotate it in a certain direction. There will be balls (certainty=60%).

- Patrick

Re: Low Cost Field BOM
 

What are the thoughts of the casters being used for some kind of rolling wall that is mounted in a center track system? On top the wall slides on the steel bar and on the bottom, the casters roll in a channel made with some of the larger sized wood required?

Also if you look on the McMaster Carr website under casters you will find in the category of casters will a weight limit ranging from 200 to 699 pounds, two swivel casters (one has a width of 2" and the other 1.5") for just about 22 dollars a piece. Although this discovery kind of disagrees with what I stated above because you would not need swivel casters in a track type system :confused:

My overall thoughts on stairs are that they can not be higher than a total of 4’ off the carpet of the playing field. The reason I believe this is because of safety.

Going on the idea of steps… you use the 12’ long pieces on either side of the top of a kind of ramp style center field device like we had last year. This allows 6’ on either side. You use the other 2 x 12 as stringers across this upper platform. You use the other 2 x 4 and 2 x 6 to build steps up to this platform. You then use all the plywood for sheeting the surfaces. Even with this idea, I still see something moving around the field that you are required to put things in. The flanges in this case would be at the top of the platform to assist in getting to the top.

Re: Low Cost Field BOM
 

Heres some observations from someone who works in construction frequently......

We have some beefy parts that allow for serious loads. That huge steel pipe has got to be for a pivot point. I also envision stairs because of the huge 2X12's. In their vertical oientation, they can carry way more laod than could ever be required to bare the load of a platform, but they would make perfect diagonal runners for stairs.

Also, 1/2" plywood is plenty strong for a lot of weight. Thats what is used on most residential roofs.... But we are given 1 sheet of 3/4. I predict it is for a platform or other area that is traversed frequently.

What does this boil down to?..... A huge strcuture (pendulum?) that pivots about some steel pipe. There will also be extensive plywood structures along with some moible peice (if the castors are left intact?)

aim me: Ih8migs2

Re: Low Cost Field BOM
 

well.

i dont wanna sound like a sore idiot..its just that..i think itd be a lot better for all of us to stop speculating on these things (its 2:09 AM here), and get some sleep to prepare us for the build season ahead. we all have our views and we'll keep guessing...but to realy what end?

we have engineers/constructionists/students; and other useless genetic accidnets :] all posting for PURE speculation ...hey.. i guess you gusy are that "spirited".

Re: Low Cost Field BOM
 

But... you forget one thing man! This is just a cheap BOM.
So, those listings might actually be two different materials in the final BOM.

In the cheap BOM of last year, they used plywood to replace the metal grating floor AND the lexan walls and floor as well as the standard wood parts.

As for the Toilet Flange, that was used in 2002 as a sleeve for the longest piece of pvc pipe in the center of the rolling goals.


Oh, BTW, I noticed this on a page on FIRST's website about the Manchester Agenda for the workshops. :

Pressure Sensor Application to a FIRST Robot
David Britton - Texas Instruments

AND

Application of Limit Switches to the FIRST robot
Presented by Rockwell Automation

Just thought I would throw that in there to make your programming team go as crazy as we are going with this BOM trying to figure out how to intergrate that into the big picture!!! lol

Re: Low Cost Field BOM
 

From doing a bit on construction myself, aren't wall studs put together 30" on center? If using that measurement and assume the 2x6x8's (11) are being used for these "studs", then there is an inner dimmension somwhere near 330" from the two outer studs. 330" = 27 1/5', which is almost 28'. With 7 sheets of 4x8 plywood next to one another, you get 28'. Thus an 28' by 8' rectangle is achieved on only one side of the 2x6's.

This would also explain some of the boxs of deck screws, as it would take a good 1/2lb just for this rectangle.

Sounds like a platform, which will be raised or accessible by whatever the 2x12's are used for. I think the casters and the 3/4" plywood will be used for the *single* goal, and I like the idea that the steel pipe might be for hanging from again.

-Rc

Re: Low Cost Field BOM
 

[quote=patrickrd]Grrrrr. I hate it when somebody :caugh:dave:caugh: knows something I don't. 10 ft/sec...

I also noticed how Dave had vmax=10ft/sec in the end of his message. If you head over to another thread about possibilities for this years game, he also ends one of his messages with a quote from "Stairway to Heaven" by Led Zepplin. He says:
"Yes, there are two paths you can go by,
But in the long run,
There's still time to change the road you're on."

hmm Stairway and being able to change roads after you have picked one...sounds autonomously suspicious to me. :D

-Rc

Re: Low Cost Field BOM
 

That just reminded me of the lego league game for this year... maybe this year's FRC game will also include a spot where you start and have to knock a wooden ramp onto the playing field that allows you to enter the rest of the playing field...

and maybe if you can get back into this zone and raise your ramp up, you get points.. hmm... oh the possibilities :]

Re: Low Cost Field BOM
 

Here are some of the things I am wondering about, and some thoughts to go along with them.
1. 2 different thicknesses of plywood (7 sheets of 1/2" and 1 sheet of 3/4") 2. 3/4" That's some heavy plywood.
3. As noted above the 2 hex nuts & bolts?
4. 2 pieces of 2x12x12, that's some big lumber, half the width of the playing field each or... the full width put together.
5. Lots of 2x6's some serious structure.
6. The 3 - 5" wheels and the 3 - 2x12x8, only things in 3's
7. 2 toilet flanges? 1 on top 1 on bottom?

Re: Low Cost Field BOM
 

[quote=JosephM]1.) Having a moving gate to get across the field.


Im not really involved in the lego league but didn't their game have a door or gate of some sort?

-Pat

Re: Low Cost Field BOM
 

I think one thing is obvious. We are definately going to have some sort of structure. A pretty big one. The only thing i can see the 2x12s used for is stairs. The toilet flanges are obviously going with the 3" PVC. Dave has been giving some pretty freaky hints and people seem to have some pretty good insight into their meaning.

The beefy steel pipe. That is definately structural or at least somethign rigid like the bar last year.


The pressure sensor thing. I assume they probably mean either a static pressure sensor or an air pressure sensor. Either way both can be quite useful.

Be careful, Dave can be misleading
 

Or maybe Dave's being his typical self and playing with everyone's mind. I wouldn't put it past him to throw out clues that have multiple meanings, one of which is a common guess for the game (stairs), and expect everyone to bolster their own theories about that common guess. All the while he's snickering because everyone's missing the real meaning of his hints. Anyone remember last year's quadratic equation? Didn't we all guess that the game was about projectiles?

Re: Low Cost Field BOM
 

Hey folks!

Metal in Motion has a thread on their site with some interesting ideas. www.metalinmotion.com

Go to the General Discussion forum on the message board.
Go to the thread that is titled Playing Field BOM is out!

Re: Low Cost Field BOM
 

Hmm...maybe it's just me, but I'm thinking of a gigantic, three-paneled rotating gate...using the unit circle as an example, we'd have gates at the 120 degree, 240, and 360 degree spots, with a castor on the bottom of each gate.

Hard to explain and probably completely wrong, but at least I know what I'm talking about...

Re: Low Cost Field BOM
 

OOH! OOH! KOTH with three connect rotating stairs instead of a ramp!