The Game Floor
 

Ok, does anybody know what the game floors actual technical name is and/or where (if possible) can you get some, or know of any place that you can go to and use a floor of similar characteristics

Re: The Game Floor
 

From Section 6 of the manual.

Re: The Game Floor
 

do u have any idea where we can get regolith or something like it for a mock up crater?

Re: The Game Floor
 

how can we drive on this without crashing?

Re: The Game Floor
 

Very carefully. Sorry, but you're just going to have to be very careful.

Re: The Game Floor
 

Crashing is inevitable. However, lower friction reduces chance for damage. Instead of holding its ground and crunching, it slides out of the way. That's why the rules are more lenient.

Re: The Game Floor
 

The manual indicates that it's supposed to be the Gel-Coated Glasliner FRP (which is smooth), but pictures from the kickoff event show the floor being the pebble-textured Glasliner FRP. I assume the actual material used at kickoff was correct, but you know what they say about assuming things...

Re: The Game Floor
 

Menards sells this very simmilar FRP panel by the paneling I believe the current cost (West Michigan) is something close to $27 for a 4X8 sheet.

-Mike AA

Re: The Game Floor
 

...or about $1500 to cover a full field... ouch.

We picked up 2 sheets already for about $30 each.

Re: The Game Floor
 

Also worthy of note is the coefficients of friction listed in the manual
this means that it takes something like 10 seconds to cross the field at the very best. (Force of friction=force exerted on robot sideways, max acceleration = g*mu, mu inline static=.06, thus g*mu=.588 m/s^2)

Re: The Game Floor
 

The floor looks like the fake ice I've seen at some hockey camps.
A few years ago I had a couple sheets of it to work on my goalie training.
Sadly the place I got it from is no longer in business and I don't remember the exact name of it but I've seen similar stuff at Hockey Giant for about $30 per 4x8 sheet.

-p :cool:

Re: The Game Floor
 

I have to ask this, the rules state that we can buy and use additional official 2009 first wheels. I suggested that making a bot with multiple wheels (12 wheeled beast) would give us an edge however someone said that it would just redistribute the weight.

What I'm asking is (to someone who knows more physics) will more wheels (more surface area) give any real increase in traction? If so (or not) how is this calculated?

Thanks,
-Cody

Re: The Game Floor
 

Frictional force is completely independent of surface area.
Maximum frictional force is simply the weight of the robot times the coefficient of friction. Ff = u*Fn

Re: The Game Floor
 

So make you bot as close to 120 lbs as possible and don't worry about surface area. Hummmm...

Re: The Game Floor
 

... or, to put it differently ... you can decide to put 1/4 of your weight on each of 4 wheels, or you can put 1/12 of your weight on each of 12 wheels.

... but if you aren't driving all 12 of the wheels, your net amount of force that turns into robot locomotion is cut waaaay back.

Re: The Game Floor
 

From looking at the rules and the video we think its the "Glasliner FRP"
but the bumpy or "rippled" kind.
In 10.2.4.1 the rules say "The wheels supplied in the 2009 KOP are very different from previous years’ kit wheels. The tread material is Celcon M90, and has the following coefficients of friction on white, rippled fiberglass plastic sheet" then states the coefficents.

haven't found a dealer forsure yet but there are places in the states that sell it. dont no about prices yet. any one no where to buy?

Re: The Game Floor
 

we know** its "Glasliner FRP".

Re: The Game Floor
 

The floor material is a thin laminate pretty much exactly like the one you find on the walls of communal showers or in the kitchen or bathroom of a taco bell, the slightly bumpy white plastic stuff on the walls.

We found this stuff at our local Lowes (nice when your building materials are 1/2 mile from your shop) for about $28 per 4x8' sheet if I remember correctly.

-q

Re: The Game Floor
 

Classic model for friction does not depend on surface area.

maximum friction force F is given by the equation:

F=u*N

where u is the coefficient of friction between the two objects and N is the normal force between them.

in our case the net force that the floor is applying to the robot (the normal force) is the weight of the robot.

so:
F=u*W in our case.

so as you can classic friction does not depend on surface area.

if you were to model each wheel individually you would get a lower normal force (roughly the weight of the robot divided by the number of wheels) on each wheel so that N=W/n (W=total weight, n=number of wheels.)

so the force from each wheel would be F'=u*W/N

and we have n wheels so we get a total force of: F=F'*n=n*u*w/n=u*W

magic! :)

classic theory of friction breaks down in a lot of cases (for example spikes on a carpet), but should be very close to the reality in this year's game.

-Leav

Re: The Game Floor
 

Also....will adding a lot of weight really help you stop and move easier. I mean yes you will get more force from friction but what about F=ma. You will need more force to slow yourself down as well so having more weight wouldn't really do you as much good would it???

Re: The Game Floor
 

According to the classical model, your acceleration will not depend on the weight of the robot.

a = F/m = umg/m = ug.

However, extra mass will aid you in collisions.

Re: The Game Floor
 

Don't forget that extra mass will also help you drag the trailer around. I would suggest that if your robot comes in underweight you'll do well to ballast it up to 120 pounds so that the ratio of weight on the undriven (trailer) to driven (robot) wheels is minimized.

Jason

Re: The Game Floor
 

Under normal circumstances, the "surface area" is irrelvant to traction. Friction is proportional to the
normal force (that is the force perpendicular to the surface, usually the weight supported by the wheel.
You can calculate friction from the dimensionless coefficient of friction multiplied by the Normal force on the
wheel. Do remember that forces (including friction) are vectors.

As in past years, a driven wheel cannot impose greater torque than that which occurs just before the wheel
breaks traction. The ability of a drive train to supply more torque than this is not very useful, although
it looks like the there is an 18 inch carpet border which will yield quite different characteristics and some
serious pushing may still be possible around the edges.

The main difference this year is that with a coeeficient of friction of approximately 0.06 rather than the
typical 1.0 - 1.2 or so, the peak torques on the FRP will be about 1/6th of those of past years.

Having 4 driven wheels will increase your pushing force (and acceleration) because all wheels will be able
to push (before any of them start of to slip). As in past years, 6 wheel drives will still be useful because
with a raised center wheel, you will always have two wheels slightly off the floor (or with very low normal
force) and the effective wheelbase will then be about half that of a 4 wheel drive without the center wheels.
This may be quite important with the required wheels. Note that (assuming the supplied information is correct)
the transverse coefficient of friction of the wheel/FRP interface is more than twice that of the inline
coefficient. Do not assume that it will be easier to skid steer on this surface. It may actually be much
harder. You will have to do the physics and the math and it might be best to get some input from your engineering
mentors on this.

I think that some of the interesting challenges of this year's game comes from deciding which "rules of
thumb" to throw away and which ones to keep.

Re: The Game Floor
 

Our team is known for being overweight (lots of 8020 == heavy), I doubt hitting 120 lbs will be a problem :)

To writchie: Thanks! That makes alot of sense but I suppose it doesn't change anything. It looks like FIRST wants to make sure that this will be a slippery game with luck involved.

Re: The Game Floor
 

Speaking of the trailer, does anyone have any feedback on how easy it is to whip the trailer transversely? If the bot strafes sideways, how willingly does the trailer follow?

Also, here's a site with some sample pricing - hopefully you can find it cheaper locally:

http://www.frpshop.com/liner-panels-c-3_4.html

Maybe we'll get blue and pretend it's a water game....

Re: The Game Floor
 

We were told by another team that Home depot carries it for $13.00 a sheet. I hope this is true instead of that $28.00. It is really thin material used on bathroom walls so I don't see why it would be $28.00. We are planning on going tomorrow and buying 5 or 6 sheets.

Re: The Game Floor
 

Can I have a definition of incline friction vs transverse friction, please. I thought I was paying attention pre-season, apperentally not.

Re: The Game Floor
 

Inline friction is along the direction of the wheel's rotation (rolling friction), transverse friction is along the axis of rotation (sliding friction).

Re: The Game Floor
 

Like the real world, luck is always an element. I suspect, however, that luck
will be more involved with miraculous "shots" in the last 20 seconds by human
players. Changing the physics of the game, IMHO, makes it more a matter of
engineering than luck. As always, expect to see some amazing bots.

Re: The Game Floor
 

Chances are the one at H.D. is a thinner version with different surface which is why its less expensive.

Edit: The $28 4X8 panels are the .090 thickness, the $13 is most likely the .063 panels which are much thinner and more flexable.

-Mike AA

Re: The Game Floor
 

We fount some at Home Depot for around $30 for a 4X8 sheet.

Re: The Game Floor
 

Still confused whether this is the smooth surface (implied by "gel coated" as stated in the Arena Manual) or rough as stated by some observers. This seems important to me... Don't want to run off to local home center quite yet only to get the wrong kind !!

Re: The Game Floor
 

Can someone measure the thickness of what is known to be the right stuff?

Re: The Game Floor
 

It has a bumpy surface, assuming we got the right stuff. Kinda shiny too, if you use rubber, like on your tennis shoe you actually get good traction. Too bad we gotta use the "rover wheels"

Re: The Game Floor
 

I'm not sure we will know what the "right stuff" is until we get access to the Q&A forums Wednesday.

Re: The Game Floor
 

I was just at Menards, Lowes, and Home Depot and 'gel coated' means that it has a glossy surface which makes it more durable.

Re: The Game Floor
 

The glasteel.com (one of the biggest FRP manufacturer)
defines gel coated as a smooth and embossed as a
pebble finish. If I am correct FRC manual(6.2.1)specs
the floor as a "gel-coated".

Re: The Game Floor
 

That is exactly the brand name that Home Depot sells. I have 4 sheets of it sitting in our lab. Its not very thick at all but extremely flexible.

Also just wondering, does anyone else notice that after running the new wheels on this stuff after a while the floor and wheels start to wear (also they start to smell)? I getting white dust off my wheels only after running them back and forth after a while. Maybe we need to break them in first.

Re: The Game Floor
 

in the rules it specifically says it wants them in as close to out of box condition as possible...aka no "breaking in" although it certainly would make driving easier

Re: The Game Floor
 

I have not checked it out yet, but I hear that this material is available at home depot for right around $28 per sheet.

I am going to go take a look tomorrow morning. We probably will not buy enough to build a whole field because of the cost. But we will at least do some of it.

Re: The Game Floor
 

The animation clearly shows a slightly bumpy surface if you watch carefully. But, i don't know how the "gel coating" affects the surface.

Re: The Game Floor
 

You can also hit up any home improvement store and find this stuff. ex Home Depot, Lowes, ect... All it is is pretty much that really cheap slippery plastic covering that you will find in bathrooms.

Re: The Game Floor
 

Could somebody who attended Kickoff in NH please confirm whether the floor was the smooth "gel-coat" or bumpy "pebbled-finish" Glasliner FRP?

Re: The Game Floor
 

glasliner frp, fiber reinforced polymer, is the name of the flooring and we found it at lowes

Re: The Game Floor
 

photos from kickoff show that the surface is pebble coated so thats what we bought.

Re: The Game Floor
 

Based on simple physics principals the friction force is independant of the area.

In reality it may and will be quite different.

If the surface has a slight texture to it there may be an advantage to fiewer wheels. The wheels look like last years kit wheels which have a soft surface compound. With sufficient weight on the wheel the compound will conform to any irregularities in the surface giving you additional traction.

The real question is how much weight is needed per wheel to obtain the optimal compound deformation and the most traction.

If you have a skid steer 4 or 6 wheel drive system you need to generate enough force to slide wheels sideways. Skid steer systems in general do work well on ice becuuse you are limiting your self to kinetic friction which is very low.

Think of a car on ice. As long as you accelerate and turn slowly you remain in control because static friction dominates.

If you slam on your breaks, accelereate fast or turn to quickly all you have is kinetic friction, newtons first law takes over and inertia is the driver.

This surface does seem to give a decided advantage the the established teams with four wheel drive systems that steer each wheel. These are complex drive systems that require a lot of programming and are difficlult to design and debug in 6 weeks.

Re: The Game Floor
 

when dean's bot collided with the other one, it looked just like some of the ice collisions up here in north Idaho... so some tips for ice driving:
1) start slow, otherwise you'll peel out,
2) controlled drifting can stop you faster occasionally
3) anti-lock breaks are your beast friend, or just decreasing speed first
4) more weight does mean more friction, but also you take a LOT longer to stop
5) try to get practice on ice if you have it near where you live.

i just wish that ice rink here in town had a stronger roof... it collapsed under the snow...:ahh:

Re: The Game Floor
 

The attached photo was posted by our friends at The Blue Alliance Kickoff 2009 on Flickr.

The picture leaves no doubt that the pebbled-surface Glasliner is the "right stuff"...

Re: The Game Floor
 

They are not the same as last year's kit wheels. The wheels this year have a very hard surface that does not conform at all.

Re: The Game Floor
 

From the photos and the section of the manual dealing with field layout and marking, I'd guess that they're using Glasliner FRP Basement Liner (8' width rather than standard 4') with fibre-glass tape on the seams. Much easier for field set-up. Is it on top of carpet? At 0.060" thickness, could be very sensitive to the surface it's laying on.

Time flies like an arrow but fruit flies like a banana,
Olde Bill

Re: The Game Floor
 

I'm assuming they will be using these laminated panels as the floor covering:

http://www.glasteel.com/ingles/Detal...1262_1285.html

Any ideas where these panels can be purchased locally???

Re: The Game Floor
 

The surface can also be found at most Lowes and Home Depot stores

Re: The Game Floor
 

Its been a long time since I have posted on here, I been out of robotics for about 4 years now. Just busy with work. Hopefully getting in involved with my old team this year.... anyway

I am so happy they changed the floor. I was wanting them to change the floor since I was a Member back in 2003. Good luck to all

Buying Regolith
 

Does anyone know where you could buy or order Regolith?

Re: Buying Regolith
 

FYI there's already a thread on this - Please search for Glasliner FRP per the manual. People have gottem them at HomeDepot and lowes

Re: Buying Regolith
 

So u can find it at home depot or lowes?

Re: The Game Floor
 

Menards just put these panels on sale starting today thru 1/18/08 if I remember right for about $24

-Mike AA

Re: Buying Regolith
 

I found a similar material at Home Depot. The only difference is that it's not the GlasLiner brand. It's still the FRP .09", fiberglass sheet. Of course I would definitely be able to confirm this if FIRST included a sample in the KOP.:mad:

$27 for a 4x8 sheet

Re: Buying Regolith
 

I know! I wish FIRST would have given us some of this stuff.... oh well... :(

Re: Buying Regolith
 

even just a 6"x6" square would have been fine, just so people who couldn't make it to NH could see exactly what it was! the most important game piece this year, and no sample!!!

Re: Buying Regolith
 

Menards has it on sale I'm told. $24 before tax for a 4'x8'

Re: Buying Regolith
 

34 with tax in hawaii. :mad:

Re: The Game Floor
 

we found this material at lowes. has anyone else seen or look at this?

http://www.chiefdelphi.com/forums/sh...threadid=71238

what do you think?

Re: Buying Regolith
 

Bah, you guys are lucky. Home Depot has FRP panel here in Canada, and while it's not the Glasteel Glasliner stuff, I imagine its very similar, but a 4x8 is $46.57.

Re: Buying Regolith
 

i'm checking with my local supplier to see if they carry Regolith, to see what they can do for a bulk order for us Canadian teams

Re: The Game Floor
 

Does anyone know how the regolith sheets are attached/assembled to the field?

Wondering how floppy it might be, can't seem to find it in any drawings, and just too impatient to wait for the official ones I guess.

Re: The Game Floor
 

Another interesting thought... This stuff appears to be something like 3/32" thick. That could cause interesting drivetrain instability if its just taped to the top of the carpet, instead of making the transition flush. It can (and likely will) result in one or more wheels losing contact with the field, depending of course, on drive configuration.

Re: Buying Regolith
 

You do realize Regolith is not a brand name, right? It's what the surface of the moon is covered in. Look for Glasteel or Glasliner.

Re: Buying Regolith
 

i know my supplier is looking for glasliner FRP

Re: The Game Floor
 

So, does anibody know finally whether is ''pebble'' or "gel-coated" finish?

Re: The Game Floor
 

There's your answer. :)

Re: The Game Floor
 

The way the wheels are arranged and the way the robot weight is distributed on the wheels will have a major effect on how the robot handles and turns, but will not affect the available traction.

Re: The Game Floor
 

The manual states:

6.2.1 The CRATER
The playing field for Lunacy is a 27-foot by 54-foot carpeted area, bounded by two Alliance Station Walls and a Guardrail System. This field is known as the "CRATER." The majority of the CRATER is covered by a 24-foot by 50-foot surface known as the "REGOLITH." The REGOLITH is made of "Glasliner FRPtm" gel-coated, fiberglass-reinforced, polymer material. This forms a tough, rigid surface that has been specifically selected to have a low coefficient of friction with the acetal-treaded ROVER WHEELS used by the ROBOTS.

The Game Floor Canadian Source
 

Below is a reply I received from the Glasliner FRP company as to availability in Canada. Not the Canadian stuff is close...I have not attached the tech sheet as it is available on the Glasliner website. Hoipe this helps.

Dear Sirs,

Thank you for your interest in our products. Attached please find our
Glasliner FRP tech sheet for your review.
Glasliner FRP is primarily used as a sanitary wall covering for
commercial kitchen and restrooms, so because this is a non-traditional
use of FRP there is no information regarding a coefficient of friction
for the .090" Textured One Side product.
The local Home Depot carries 4'x8' panels (SKU 121586) of the product.
It is not identical, but it is as close as it will come. Again, because
this is a non-traditional and non-standard size of FRP, there are no
8'x50' coils available.
We hope this helps, but if more information is needed, feel free to
email Ken Freeland at kfreeland@Glasteel.com or contact FIRST at:
F.I.R.S.T. (For Inspiration and Recognition of Science and Technology)
200 Bedford St.
Manchester, NH 03101
V: (603) 666-3906 X479 F: (603) 666-3907
URL: http://www.usfirst.org

Sincerely,
Javier Vasquez
Vice President Sales & Marketing
Glasteel

Re: The Game Floor
 

Does anyone know how to put the floor together?

Josh B

Re: The Game Floor
 

The actual floor is pretty pricey, however you can get some similar results on any tile floor.
Our team is using whiteboard material, which is fairly cheap and has mostly similar qualities

Re: The Game Floor
 

It would be useful to retest the frictional coefficients of the wheel after the FRP floor panels have been sprayed in a thin layer of axle grease. This would simulate the conditions of a real field, where most robots would tend to sling small amounts of lubricant, especially in cases where the robots are spinning their wheels at full speed, trying to move.

I think FIRST should have the field-reset crews carry rags to wipe up any egregious amounts of slung lubricant. After every few matches, they should have the field-reset crews wipe the entire field with a wide cloth-covered broom. After the matches end each day (and in the down-time between qualification and elimination rounds), they should clean the entire field with soap and water.

Re: The Game Floor
 

Does anyone know if it is possible to buy the floor online

Re: The Game Floor
 

you can purchase this material from home depot or lowes. it is about $32 a sheet at home depot and around the same price at lowes.

Re: The Game Floor
 

Does anyone know about buying the stuff online. The closest hardware store from us is 2 hours away

Re: The Game Floor
 

ya... we found ours at lowes.