Discs are essentially wings with an upper surface only. The wider the rim edge (think destroyer) the less drag is created underneath. If the bottom surface was completely covered/ smooth, like the wing on any efficient glider, the disc would fly farther, faster and have better glide, by allot.
Of course there are problems. The new wider rims are getting more difficult to grip for smaller hands, so going much wider will have consequences. The aerobie epic (i know i know) has that extra wide rim on one side only, creating more of a double surface in flight, but lots of wobble and unusual flight characteristics.
If the bottom surface was completely covered, you would need to be able to get your hand to grip the disc, but maybe there is a way. A flexible membrane on the disc's bottom that can be griped, and will spring back when released? Or perhaps a harder, more rigid lower surface with twin symmetrically placed openings opposite each other, just big enough for a hand to grip inside of.
I know that disc stability would be impacted by a double surface, but there are techniques already in place to tweak this.

anyone have any thoughts?

The landing would suck!

yeah, that would sure make it land bad!

are you talking like a track & field discus?

http://www.track-and-field-equipment-guide.com/Images/400x360/Stackhouse_Nelco_Women_s_Olympian_Discus.jpg

You would never meet the diameter to weight ratio needed with the center full...

i was thinking the same thing but maybe he's not thinking about w/ the rules... just 'in theory' (or the center could be hollow but im not thinking that'd fly too well)

are you talking like a track & field discus?

http://www.track-and-field-equipment-guide.com/Images/400x360/Stackhouse_Nelco_Women_s_Olympian_Discus.jpg



Thats a cheap discus... I used a Delphi brand disc that was created for the world record holder at the time. :p

But I got out of college in 03 though so maybe things have changed :D

No guys, not a discus, or a hubcap. A stretchable membrane would add 5 or 10 grams, or a thin solid plastic piece that would be installed after the injection mold. PDGA certifiable? there are some pretty unusual certified discs out there, so maybe. It all might sound strange, but the next time you fly take a look underneath the wing and see if anythings down there.

the next time you fly take a look underneath the wing and see if anythings down there.


PDGA Approved is definitely one thing you won't find under there :)

I wouldn't think a flexible membrane could stand up to the abuse a disc takes from hitting trees and the ground. If I could find a big enough balloon, it would be interesting to build a prototype.

Would reducing drag on the underwing make it more overstable or more understable? It should give the disc more lift and thus, more glide.

As an experiment, take a small diameter disc and jam it inside a jaguar and see how it flies.

Then you've got a whacky weight problem and a dome on the underside and nothing to grip on.

As an experiment, take a small diameter disc and jam it inside a jaguar and see how it flies.


.. like a huge Little Flyer

Would reducing drag on the underwing make it more overstable or more understable?



I would say more understable as there is less contact on the deflection angle which give most discs their resistance to turn. ( example is a bead on a discs wing makes more drag and the disc more overstable)
I am not sure reducing drag automatically increases lift.