Explanation of the physics of flying discs (FIXED)

[wolfmandragon]

The only logical conclusion I can come to is that only grip really effects the spin imparted to the disc for any given speed. all that matters is how much of a pinch you've got at the end and where that fulcrum is located. The style of the throw does not enter the equation. Less of a pinch force or inward on the disc=less spin. More of a pinch force or outward on the disc=more spin. However, I think we can all agree that you want to be gripping the disc close to the rim, not out on the flight plate, so I think the argument is impractical. And a loose grip+high launch speed equals early release, also undesirable. So really the question isn't can you consciously influence how much spin is imparted....It's a question of how to produce the most spin for any given throw. And that is simple. Create as fast a hand speed as possible and hang on as tight as you can.

This would only be true if the fulcrums all moved on the same path, but they do not. Fast hand speed straight forward will create zero spin. The disc needs to be moving very fast on a straight-ish line before the contact point is pulled off this line. The quicker the contact point is pulled off line, the faster the spin. The are no free lunches, so some of the forward momentum is robbed and translated into spin. The amount of energy needed to create spin is less than the energy needed to create flight speed, so not a terrible big deal.

Different styles of throws move off line at different rates. It's not about conscious control of how much spin is being imparted, it is about the entire movement chosen and performed.

As far as holding on as tight as I can, I have very good grip strength, the disc is not leaving my hand.... Period.

 

[sidewinder22]

Watch the Swedish throwers on slow motion and you will see a loose wrist. A locked wrist saps power out of any movement. The wrist is loose up until the hit, then it goes firm.
Experiment with it, try locking your wrist before the back swing and see what it does to the disc. The tension of locking your wrist will spread to your shoulder.
If it was easy to have the timing down perfect, we would all be pros. It takes some students years to learn how to do the proper loose tight loose sequence needed to perform a proper strike. I am using a strike, something that is much easier measured, to show what I mean here.

Several top distance throwers have said they throw with a "locked wrist". The wrist can be somewhat locked into a position before the throw without much strain because there is no momentum on the disc yet. It's only when the momentum increases that firmness increases to somewhat resist bending and loads. A firmer spring that moves less can load and unload more momentum.

 

[Olorin]

Happy 10th Birthday DGCR!

Thread #2250.

Lots of good information here but it is mixed in with a great deal of errors so you have to sift out the nuggets. In the end, there is still a great deal that we just don't know for sure about the aerodynamics of flying discs. Look for links to Master's theses and other scholarly papers for more reliable information.

 

[Olorin]

DG Resources has a summary with links to find technical research papers on the aerodynamics of flying discs.

 

[Olorin]

My summary of what makes a RHBH flying disc turns right at DG Resources.

 

[Olorin]

My summary of incorrect aerodynamic theories of the physics of flying discs at DG Resources. (incomplete)

 

[Olorin]

There's only one fact of frisbee fysics that I know for sure:
"Flat flip flies straight"

(I wonder if that eminent aeronautical engineer, Dr. Headrick, coined that jingle too?)

 

[FlipFlat]

There's only one fact of frisbee fysics that I know for sure:
"Flat flip flies straight"

(I wonder if that eminent aeronautical engineer, Dr. Headrick, coined that jingle too?)

"Flip Flat flies straight "

 

[DavidIYork]

Wow. This was a very interesting read. Thanks so much for putting that together! I'll have to go over this thread again, so much valuable info. I just started playing a little over a month ago and this feels like a goldmine into understanding more about the flight of discs ��

 

[OveHalseth]

What a great thread!

I'm just missing one bit of information, and that is how much spin will affect the flight path.
In other words if a disc is thrown exactly the same, only thing differs is the amount of spin, how would that affect the flight?

I'm not sure how much you could change the spin of a throw, but if you are dragging the disc by the nose in the throw, you will generate less spin than if you keep the grip on the outside of the disc for as long as possible during the throw, and at the end it will snap out with a lot more spin.

One observation is that wet discs tend to be less stable, and my guess is that that's because you are not able to get that much snap and spin on a wet disc.

And that might also be why sidearm throws tend to need more stable discs?

 

[hugheshilton]

And that might also be why sidearm throws tend to need more stable discs?

In general there tends to be less spin at a given disc speed for a sidearm than for a backhand. The spin stabilizes the disc, especially during its initial high speed phase of flight. Thus less spin means that a disc is going to turn more at high speed so often players use more overstable discs for forehands. Then again, it's also a little easier to roll over your wrist and throw with a little anhyzer forehand so more overstable discs tend to correct that tendency as well. Players with a very clean forehand release (less OAT) and a lot of hyzer in their forehand release can still get away with understable discs though (see Big Jerm with his mids for example).

 

[wolfmandragon]

What a great thread!

I'm just missing one bit of information, and that is how much spin will affect the flight path.
In other words if a disc is thrown exactly the same, only thing differs is the amount of spin, how would that affect the flight?

I'm not sure how much you could change the spin of a throw, but if you are dragging the disc by the nose in the throw, you will generate less spin than if you keep the grip on the outside of the disc for as long as possible during the throw, and at the end it will snap out with a lot more spin.

One observation is that wet discs tend to be less stable, and my guess is that that's because you are not able to get that much snap and spin on a wet disc.

And that might also be why sidearm throws tend to need more stable discs?

How one grips the disc and how hard one comes off line both affects the spin of the disc.
As a general rule, there are exceptions, the faster the disc is spinning, the more stable it flies. Stable, not overstable.
Theoretically, there is some Magnus effect, bit the disc RPM is too low to be much of a factor.

 

[ILUVSMGS18]

What a great thread!

I'm just missing one bit of information, and that is how much spin will affect the flight path.
In other words if a disc is thrown exactly the same, only thing differs is the amount of spin, how would that affect the flight?

I'm not sure how much you could change the spin of a throw, but if you are dragging the disc by the nose in the throw, you will generate less spin than if you keep the grip on the outside of the disc for as long as possible during the throw, and at the end it will snap out with a lot more spin.

One observation is that wet discs tend to be less stable, and my guess is that that's because you are not able to get that much snap and spin on a wet disc.

And that might also be why sidearm throws tend to need more stable discs?

Clean form is key to being able to throw US discs FH or BH. I used to have a cleaner FH and could FH almost any disc (I once threw a Champ SW FH dead straight over 250', when I expected it to turn over, and went OB as a result), thus throwing FH with US discs is very possible. I've shaped some crazy lines FH with beat Rocs and Comets, but I need to clean up my FH form again, even though I no longer truly need a FB for FH, its still not what it was and isn't how I would like it.

 

[armiller]

More spin means more angular momentum. Thus less high speed turn and less high speed fade. Ad Hughes said, forehands tend to have less spin. I think this is due to the different wrist and arm mechanics of fh and bh. I do think forehands tend to fade harder at the end, and spin is probably the main reason. At the beginning of flight, the decreased spin probably contributes to ease of flipping fh throws. BUT I agree with Hughes that it's also way easier to roll wrist and cause OAT, so it's a little tougher to say for the high speed part of flight.

 

[armiller]

Bump. I just spent too long looking for this thread. Any chance it could become a sticky, maybe in the technique or strategy thread?

 

[JuanA]

Bump. I just spent too long looking for this thread. Any chance it could become a sticky, maybe in the technique or strategy thread?

I love threads that talk about disc flight and physics, and how they relate to technique. I'm going to read through this one, and the other one you bumped recently as well.

 

[elmexdela]

quick questions

do discs fly moar us or os in the winter

and do discs have less or moar d potential in winter

 

[R-Ogre]

quick questions

do discs fly moar us or os in the winter

and do discs have less or moar d potential in winter

More US, less D. Anything that increases dynamic pressure or air density (low altitude, low temp, faster throw, headwind) makes a disc fly more US and robs it of distance potential via increased drag.

 

[elmexdela]

More US, less D. Anything that increases dynamic pressure or air density (low altitude, low temp, faster throw, headwind) makes a disc fly more US and robs it of distance potential via increased drag.

im still confused by this

i experience moar os and less d

or is it suspect to having a noodle arm that is cold and heavily clothed and not as proper foot planting

 

[R-Ogre]

im still confused by this

i experience moar os and less d

or is it suspect to having a noodle arm that is cold and heavily clothed and not as proper foot planting

That would be my guess. But I could be wrong about temperature effect.