Ramp Materials

[Rosiebotboss]

Welded steel mesh from the ramp used in Stack Attack of 2003 on an aluminum frame. 27 inches wide, almost 10 feet long, ~23lbs

[Brandon Holley]

carbon fiber sounds pretttttttttty good

[S-man]

Aluminum & stuffff....

[Matt Gardner]

Our team is now looking at Alumalite as a viable option (thanks Dad1279!). Does anyone know a local distributor of Alumalite? We are in Burlington, Ontario (In the Greater Toronto Area). We need at least 4'x10' sheet perferably in black/pink, but we'll buy whatever is cheap and available. We'd like to be able to pick it up Thursday if its close enough, because we don't have enough time really to have it shipped in...

Also, Dad1279, or someone from his team, or anyone who's dealt with alumalite...Do you know the mass per square foot of Alumalite? And is it really strong enough to support robots (with a proper frame, of course)?

Thanks again everyone, you've all been a great help...

[MrForbes]

what is "Alumanite"?

never heard of it....google doesn't seem to know much about it....

[Matt Gardner]

Originally Posted by squirrel

what is "Alumanite"?

never heard of it....google doesn't seem to know much about it....

look on page one, there's a link somewhere...oh, and sory, I mispelled it a couple times its actually Alumalite

[Madison]

Originally Posted by Dad1279

1279 has used alumalite: https://www.harborsales.net/fullshee...Faced%20Panels

Light & easy to cut.

Out of curiosity, what's the weight per square foot for a 1/4" or 3/8" thick piece? I wonder if it's worth our time to investigate replacing our corrugated polycabonate with this.

[Matt Gardner]

From what I've researched (it does not seem that common) it is .375 lb./sq. ft. (for a 6mm thick piece) Our team figures our ramp covering would weigh only 10 lb. if using it (awesome). My only problem is that I cannot find many teams that have used this material and do not know how well it stands up to the weight of a robot. (Moreover, it comes in a variety of colours, also awesome)

[Doug G]

We're using a carbon fiber / foam sandwich that we made ourselves. Each 40" x 38" panel weighs around 4-5 lbs. We then have an aluminum kickstand and track that sits underneath the ramp with a FP/BaneBot winch to raise the kickstand. With the motor/winch/kickstand and ramp it comes to 10 lbs per ramp.

[MrForbes]

Originally Posted by Matt Gardner

From what I've researched (it does not seem that common) it is .375 lb./sq. ft. (for a 6mm thick piece) Our team figures our ramp covering would weigh only 10 lb. if using it (awesome). My only problem is that I cannot find many teams that have used this material and do not know how well it stands up to the weight of a robot. (Moreover, it comes in a variety of colours, also awesome)

It looks like Alumalite is a sign material, two thin sheets of aluminum with a corrugated plastic core. I didn't find any specs on how strong it is in bending in a quick google search. My wild guess is that it might work as a ramp material if you can support it well, perhaps every 6 inches or so (width). But it probably dents rather easily if you apply a concentrated load to it, and might buckle. Hard to say without more info....

[Matt Gardner]

I realize the normal application, but it's not used for those little wimpy signs, either. If you look here:

http://www.signboards.com/Applications/index.asp

you can see the type of signs that its being used to build. I figure these need to be strong and impact-resistant just because they are always outside...

What I really need is feedback from someone who's used Alumalite in the past...anyone?

[MrForbes]

Originally Posted by Matt Gardner

I figure these need to be strong and impact-resistant just because they are always outside...

If those signs can stand up to the occasional flying robot, they should be able work as ramp material?

I agree, you do need some input from someone who has played with the material, or used it on a robot or something. Since it's not a structral material, there seems to be no or very little structural info about it available.

If you can estimate the thickness of the aluminum layers, you could calculate the moment of inertia and estimate the bending strength under static loading conditions. As an example, I just calculated the stress due to bending, assuming a 6" wide ramp, 3 feet long, 100 lbs load at the center. Material .25" thick, each aluminum face 0.020" thick. The maximum bending stress would be about 70,000 psi, which is about four times the yield stress of soft aluminum, and about twice the yield stress of typical heat treated aluminum alloys.

So, you would need to provide support for the ramp about every foot of length to make it strong enough to adequately support a robot....is my guess....

[Dan Zollman]

I can't really find anything about Alumalite used for something other than signs. Since it would be used in big sheets outdoors, it must be made to hold up against wind and rain. But doesn't that mean that bending isn't the force it needs to resist, since wind and rain probably hits the sign evenly? In addition, signs can have a lot of framing and support behind the surface, so it would probably have short distances between supports.
Impact is probably the only thing it's designed to resist, while I don't think it would work for a robot like 1712's since we need to save weight with as great a distance between supports as possible.

I could be wrong about all of that, but I'm just trying to figure this out. It just doesn't seem to me that Alumalite is the right kind of material for a platform/ramp surface.

[Matt Gardner]

With the frame we are building at the moment we have supports about a foot apart, I do believe... I have to check up on that tomorrow...It's true that what really matters is what kind of weight it can support, mostly I'm just wishfully thinking. I'm trying to contact the company again tomorrow to see if I can find out more information. As for impacts, we hopefully won't have any, we want smooth driving up the ramp, and smooth driving off. We are using a totally different material for the sides as well, a much stronger one... and we're hoping no manipulators smash into our ramps, either...(again with the wishful thinking)

[DonRotolo]

Team 1676 is using a welded aluminum frame of 1" square stock with 1/16" wall, covered by 1/2" steel hardware cloth (looks like giant window screen with 1/2" holes) that is 'welded' at the intersections. The approx. 30" x 35" ramp weighs about 5 pounds.

Don