Understability really one thing?

[Seedlesstom]

Obviously if a disc is so unstable that when you throw it always turns over into the ground you either are throwing it poorly or with too much speed for that disc to be thrown in the air. Maybe you should throw it nice and easy and see if it glides then? Unless you want to throw a shot that rolls along the ground.

My preferred word for this description of disc flight is glide because I learned it when I was young and it communicates the observation clearly. "Throw your roadrunner fast with a moderate hyzer angle and watch it glide for a long time." An accurate statement. I had never heard of overstable and understable until 4 years ago. I don't prefer those words anyway, I prefer "more stable" and "less stable" or soemtimes "(relative to thrown speed) stable and (relative to thrown speed) unstable", I think they describe the characteristic better. But I try to communicate as clearly as possible so I'll use whatever words I think are best to make my point.

Yes, but think about this like a science experiment. Everything in your experiment must remain constant, except your variable. In this case, the mold is your variable.

Take a roc and a wolf, both are speed 4, 21.7" diameter midranges. Throw a Lazer beam straight, flat shot with a roc. Throw a Lazer beam straight, flat shot with a wolf, with the same power.

My money is on the Roc, if you're counting where they touch the ground.

If you're not comparing apples to apples, your point is invalid. Hyzer flipping the wolf is cheating.

Diameter is another factor that affects glide...

 

[Kodachrome]

Oh, fine. I'll start.

Understability is the word that we all use to describe understability. More understable = more understable. This can be explained and complicated more using physics but that isn't objective, it's just for fun. Understanding that more understable = more understable is objective to throwing less frequently during your round.

I think he's on to something. When I switched out "understable" and used it to replace "glide" the post actually made more sense. They really are the same thing!

 

[Dan Ensor]

Anyone who thinks understability=glide needs to spend an hour throwing my Flicks with me. I can show you an understable Flick. A glidey Flick does not exist. It finds the ground just as quickly as my OS Flicks after they're both done flying.

Of course, I'm not sure I have a standard definition for glide. To me, glide is how wide the speed gap between LSS and HSS is.

 

[Jenga54]

understability really not a thing?

understability really 3 things?

feels like a buzzfeed headline click bait. well done, this should last a while again.

 

[ru4por]

I throw a Core and a Comet. They are similar in stability, if thrown with some steam they will both fly with the same understable flight path. The Comet, while having pretty good glide for a mid, does not glide like my Core. How is than explained by this theory?

 

[rhatton1]

Oh, fine. I'll start.





I think he's on to something. When I switched out "understable" and used it to replace "glide" the post actually made more sense. They really are the same thing!

:clap::clap:

 

[VictorB]

I throw a Core and a Comet. They are similar in stability, if thrown with some steam they will both fly with the same understable flight path. The Comet, while having pretty good glide for a mid, does not glide like my Core. How is than explained by this theory?

You're confusing speed and glide.

 

[TexansNation56]

if you are using understability to describe glide, you may need to re-read your dictionary. I use the word "glide" to describe glide, and the word "understable" to describe understability. two very different things.

Perfectly said right here.

 

[TexansNation56]

I throw Champion Roc3's and they have much more glide than any mid range ive ever thrown.

 

[thunder3boy]

Glide is what we use to describe the the "lift" that is caused as it travels through the air.
Stability better describes the tendency of a disc to tilt left, right, or stay straight.

Understable discs are associated with more glide because they keep the disc tilted in an orientation that optimizes the direction of the "lift" force imparted by the air as the disc travels.

I could go into more detail, but long posts are boring. Does this make sense or am I off?

 

[Jenga54]

OP-

Understability is the word that we all use to describe glide. Wrong

More understable = more glide. Wrong

This can be explained and complicated more using physics but that isn't objective, it's just for fun. Saying you're correct, because science?

Understanding that more understable = more glide is objective to throwing less frequently during your round. Wrong Putting better helps you throw less times, and being accurate with drives does too.


They are not super easy concepts, but I think it's just new player knowlege trying to go to work.
When you're new, you throw a destroyer and the thing hooks hard left and you go, that didn't glide at all!
Then you grab a leopard, and it flips right and you get more distance. It stays in the air longer, because it took all that TIME in the first part of the S curve, flipping right, before it comes back to the fade.
So it can be easy to think (as I did too) that the longer you get a disc to stay in that HS Turn, the better distance you get. Because you think of that leopard flight 'wow, look at that glide right before it hooks up at the end.'

 

[TheBeardedFatGuy]

My two cents is that Turn is the Innova rating measuring understability. Yes, a disc thrown on a sweet s-curve will typically stay in the air longer, but is that really the same thing as Glide? Is there really a definitive explanation of what the Glide of a disc is? I know Innova defines it as basically a discs ability to maintain loft, and an understable s-curve or over stable flex shot will accomplish that, but I don't think that's what's meant by the Glide rating. Any disc thrown without sufficient spin is about as aerodynamic as a brick, but it stands to reason that some disc configurations are slightly more aerodynamic than others and so will tend to remain oriented for flight a little longer. Nobody would argue that a disc in the act of tipping and crashing to the ground is 'gliding', but a disc that remains upright until it touches ground, especially if it fades more or less forward, is a good example of glide. I suspect a good way to measure the Glide of a disc would be to spin it at a set speed with no forward movement in a wind tunnel, then drop it. A disc that drops to the ground while remaining upright has more Glide than one that flips and crashes onto it's side. Slow the spin until you find the point where the disc can no longer remain level when dropped and you've found its Glide relative to other discs tested the same way.

 

[sidewinder22]

I suspect a good way to measure the Glide of a disc would be to spin it at a set speed with no forward movement in a wind tunnel, then drop it. A disc that drops to the ground while remaining upright has more Glide than one that flips and crashes onto it's side. Slow the spin until you find the point where the disc can no longer remain level when dropped and you've found its Glide relative to other discs tested the same way.

That ^ would measure aerodynamic stability rather than glide. Spin has nothing to do with "glide" other than maintaining the disc's AoA when moving forward in airspeed. Slowing the spin rate will just reduce the gyroscopic stability to maintain AoA. A disc in a wind tunnel doesn't have velocity, but it does have airspeed. Airspeed or velocity should not be related to glide whatsoever. The airspeed can provide lift, but that is not glide.

"Glide" is how much air the disc catches and rides like a parachute. It's how long the disc would take to hit the ground if dropped, doesn't matter - with spin or no spin, or with airspeed or no airspeed. You could time each disc's drop from a given height although it would be harder to maintain consistency on that method. The best method would probably be to just measure the volume of air under the disc to figure out it's "glide". Glide is rated as a relative number to a specific "disc speed" or rim width. So a glide number of 4 on a driver is very different than the glide number 4 on a putter or midrange. Obviously a driver will not glide like a mid or putter despite having the same relative glide number because the volume of air it catches is quite different given different rim widths.

 

[BionicRib]

This thread is about to get good

 

[Kodachrome]

This thread is about to get good

Hahahah, I know right? I just checked like "I can't believe someone bumped this thing" and got out the popcorn.

 

[TheBeardedFatGuy]

As usual, you misunderstand my point.

That ^ would measure aerodynamic stability rather than glide.

Exactly. Innova says Glide is the discs ability to 'maintain loft' or, put another way, 'stay in the air longer'. What attribute of a disc (not the thrower's skill) best determines how long a disc will stay aloft? Aerodynamic stability. Or you could say it's the disc's tendency to stay flat instead of turning over and crashing to the ground. Nearly all disc stability comes from gyroscopic effect, but that's getting into the thrower's domain. If we look at just the disc's characteristics, not what the thrower does to it, how aerodynamically stable the disc is aside from the stability created by the thrower-generated spin is, I think, the best indicator of the disc's ability to glide. My favorite distance drivers have always had a maximum Glide of 6, and that translates as 'stays flat longer'. Part of that is not having massive fade, but even with fade the Glide 6 discs seem to stay flatter in the fade than other discs that turn and hit the ground on their edge. They also seem to 'fade forward' more than other discs. All that is helped by the discs staying flat longer.

Slowing the spin rate will just reduce the gyroscopic stability to maintain AoA. A disc in a wind tunnel doesn't have velocity, but it does have airspeed. Airspeed or velocity should not be related to glide whatsoever. The airspeed can provide lift, but that is not glide.

Exactly. Let's say in my test you rev the disc up so it has ridiculously high gyroscopic stability. When you release (drop) it in the wind tunnel it will succumb to gravity and fall. It will also move back because of the force of the wind, but it will remain stable (flat) all the way to the ground because of the gyroscopic stability. If you repeat the test over and over, reducing the spin rate a little each time, at some point the reduced spin and resulting reduced stability will cause the disc to flip over and crash instead of dropping flat. Let's say I do this with a Destroyer and it remains perfectly stable all the way to the ground for every drop until I've reduced the spin rate to 500 RPMs (I have no idea what the actual rate would be with a Destroyer). At 500 RPMs or slower it no longer falls flat to the ground - instead if flips over. Now do the same test with a Nuke. Let's say the Nuke remains stable throughout it's drop to the ground until we reduce its spin to 325 RPMs. We've successfully demonstrated that the Nuke is more stable apart from relying purely on gyroscopic stability than the Destroyer is (again, this is supposition - I've no idea which disc would win or by how much). If you test every disc you can this way, those discs with stability at the lowest spin rates would, I believe, be your best Gliders.

"Glide" is how much air the disc catches and rides like a parachute. It's how long the disc would take to hit the ground if dropped, doesn't matter - with spin or no spin, or with airspeed or no airspeed. You could time each disc's drop from a given height although it would be harder to maintain consistency on that method. The best method would probably be to just measure the volume of air under the disc to figure out it's "glide". Glide is rated as a relative number to a specific "disc speed" or rim width. So a glide number of 4 on a driver is very different than the glide number 4 on a putter or midrange. Obviously a driver will not glide like a mid or putter despite having the same relative glide number because the volume of air it catches is quite different given different rim widths.

If this were true, then the larger the disc diameter, the better the glide, and that's just not the case. A Tern has tons more Glide than a Boss, but essentially the same diameter.

Think of it another way. If you're watching a disc fly, what event would you say marks the end of a disc's glide? I'd say it's when it is no longer 'flying' but is instead turned into its most dramatic fade phase, edge dropping and headed to the ground. If it were an airplane it would have just banked sharply and is heading for a crash. A disc that has plenty of glide either doesn't do this, or delays doing it longer. A disc with incredible glide, like the Discraft Heat, often just stays flat with mostly forward fade and slides to a flat stop like an airplane making a safe landing. That's what Glide looks like, and the defining characteristic is the discs tendency to stay flat and act as an airfoil longer than a disc with less Glide. Disc stays flat (stable) longer = disc can fly/glide longer.

 

[hook_nuts]

Yeah I do disagree with a lot of stuff, and not just about disc golf lol.

I'm not telling you what's right or wrong I'm telling you what I think is accurate and inaccurate, which are my opinions. I've been clear.

Haha letum know!

 

[Jenga54]

please someone start a "understability really three things" so thebeardedfatguy can weigh in, then we can go round the carousel another few days before Geisinger breaks the distance record.

 

[Dan Ensor]

As usual, you misunderstand my point.



Exactly. Innova says Glide is the discs ability to 'maintain loft' or, put another way, 'stay in the air longer'. What attribute of a disc (not the thrower's skill) best determines how long a disc will stay aloft? Aerodynamic stability. Or you could say it's the disc's tendency to stay flat instead of turning over and crashing to the ground. Nearly all disc stability comes from gyroscopic effect, but that's getting into the thrower's domain. If we look at just the disc's characteristics, not what the thrower does to it, how aerodynamically stable the disc is aside from the stability created by the thrower-generated spin is, I think, the best indicator of the disc's ability to glide. My favorite distance drivers have always had a maximum Glide of 6, and that translates as 'stays flat longer'. Part of that is not having massive fade, but even with fade the Glide 6 discs seem to stay flatter in the fade than other discs that turn and hit the ground on their edge. They also seem to 'fade forward' more than other discs. All that is helped by the discs staying flat longer.




Exactly. Let's say in my test you rev the disc up so it has ridiculously high gyroscopic stability. When you release (drop) it in the wind tunnel it will succumb to gravity and fall. It will also move back because of the force of the wind, but it will remain stable (flat) all the way to the ground because of the gyroscopic stability. If you repeat the test over and over, reducing the spin rate a little each time, at some point the reduced spin and resulting reduced stability will cause the disc to flip over and crash instead of dropping flat. Let's say I do this with a Destroyer and it remains perfectly stable all the way to the ground for every drop until I've reduced the spin rate to 500 RPMs (I have no idea what the actual rate would be with a Destroyer). At 500 RPMs or slower it no longer falls flat to the ground - instead if flips over. Now do the same test with a Nuke. Let's say the Nuke remains stable throughout it's drop to the ground until we reduce its spin to 325 RPMs. We've successfully demonstrated that the Nuke is more stable apart from relying purely on gyroscopic stability than the Destroyer is (again, this is supposition - I've no idea which disc would win or by how much). If you test every disc you can this way, those discs with stability at the lowest spin rates would, I believe, be your best Gliders.



If this were true, then the larger the disc diameter, the better the glide, and that's just not the case. A Tern has tons more Glide than a Boss, but essentially the same diameter.

Think of it another way. If you're watching a disc fly, what event would you say marks the end of a disc's glide? I'd say it's when it is no longer 'flying' but is instead turned into its most dramatic fade phase, edge dropping and headed to the ground. If it were an airplane it would have just banked sharply and is heading for a crash. A disc that has plenty of glide either doesn't do this, or delays doing it longer. A disc with incredible glide, like the Discraft Heat, often just stays flat with mostly forward fade and slides to a flat stop like an airplane making a safe landing. That's what Glide looks like, and the defining characteristic is the discs tendency to stay flat and act as an airfoil longer than a disc with less Glide. Disc stays flat (stable) longer = disc can fly/glide longer.

Tern doesn't glide. It just doesn't fade hard. ... Significantly less glide than a boss, really.

 

[sidewinder22]

As usual, you misunderstand my point.

Exactly. Innova says Glide is the discs ability to 'maintain loft' or, put another way, 'stay in the air longer'. What attribute of a disc (not the thrower's skill) best determines how long a disc will stay aloft? Aerodynamic stability. Or you could say it's the disc's tendency to stay flat instead of turning over and crashing to the ground. Nearly all disc stability comes from gyroscopic effect, but that's getting into the thrower's domain. If we look at just the disc's characteristics, not what the thrower does to it, how aerodynamically stable the disc is aside from the stability created by the thrower-generated spin is, I think, the best indicator of the disc's ability to glide. My favorite distance drivers have always had a maximum Glide of 6, and that translates as 'stays flat longer'. Part of that is not having massive fade, but even with fade the Glide 6 discs seem to stay flatter in the fade than other discs that turn and hit the ground on their edge. They also seem to 'fade forward' more than other discs. All that is helped by the discs staying flat longer.

As usual you misunderstand in general... Aerodynamic stability is not gyroscopic stability. Lift from forward speed also keeps the disc in the air longer, but is not loft characteristic of a disc. Glide is neither of those different things although the amount of the glide effect is related to them. Glide is disc design loft characteristic, not speed induced lift force.

Aerodynamic stability is wing design dependent and determines the disc's resistance to rolling over at a given airspeed. Because discs are a symmetrical wing, it's poorly aerodynamically stabilized to unbalanced lift force from forward airspeed. That is why we use spin to help stabilize a forward moving disc. Aerodynamic wing design stability has nothing to do with spin. Take two discs with equal wing design and PLH(same mold/plastic), but the one with a larger dome(glide) makes the disc aerodynamically less stable by lowering it's center of mass to it's relative higher height/dome. If you take two discs of equal rim width and dome and change the shape of the wing/rim, so one is concave and one is straight, you have changed the stability by changing the COM height and slipperiness of the disc but not changed the glide or volume of air under the flight plate/dome.

Gyroscopic stability is mass from center design and spin dependent and maintains the disc's AoA in trajectory while rolling/precessing. More mass away from center and more spin equal more angular momentum and gyroscopic stability to maintain it's relative AoA to it's changing trajectory and speed due to lift induced precession and drag forces. The aerodynamic wing stability design and AoA determines the direction of precession at a given airspeed. For most mortals with decent form certain aerodynamic wing designs can ensure the disc will not go into retro-grade precession(high speed turn), and this overstable design happens to have low glide characteristic.

Glide/loft is dome or flight plate design, a parachute doesn't need a wing or stability because it's not meant to go forward and lift, it's only purpose is downward resistance or maintaining loft. How much a certain glider or chute will glide does depend on how flat the glider remains during it's flight, but it's gliding ability or characteristic is dependent on the amount of volume of air it can catch when optimally flat. When a chute encounters forward airspeed, it is usually quite understable as their is no aerodynamic wing or spin to stabilize the airspeed. A parachute makes for a poor gyroscope or wing. A parachute with a wing uses the wing to create some lift from forward airspeed, so it's lift is determined by it's wing design and the glide/loft is determined by the chute air volume.

Exactly. Let's say in my test you rev the disc up so it has ridiculously high gyroscopic stability. When you release (drop) it in the wind tunnel it will succumb to gravity and fall. It will also move back because of the force of the wind, but it will remain stable (flat) all the way to the ground because of the gyroscopic stability. If you repeat the test over and over, reducing the spin rate a little each time, at some point the reduced spin and resulting reduced stability will cause the disc to flip over and crash instead of dropping flat. Let's say I do this with a Destroyer and it remains perfectly stable all the way to the ground for every drop until I've reduced the spin rate to 500 RPMs (I have no idea what the actual rate would be with a Destroyer). At 500 RPMs or slower it no longer falls flat to the ground - instead if flips over. Now do the same test with a Nuke. Let's say the Nuke remains stable throughout it's drop to the ground until we reduce its spin to 325 RPMs. We've successfully demonstrated that the Nuke is more stable apart from relying purely on gyroscopic stability than the Destroyer is (again, this is supposition - I've no idea which disc would win or by how much). If you test every disc you can this way, those discs with stability at the lowest spin rates would, I believe, be your best Gliders.

This ^ has nothing to do with Glide design. Whether the disc goes up or down in the wind tunnel would depend on the disc's AoA and the lift generated from airspeed, glide is not generated from forward airspeed although it will glide longer due to lift keeping the disc in the air longer. A parachute's gliding ability does not care if it is spinning or not or varying spin. Forward speed/airspeed does not affect glide unless it has a horizontal wing diameter, which is why all disc's with equal wing/rim diameter have their own relative glide rating for each different class of wing/rim diameter.

If this were true, then the larger the disc diameter, the better the glide, and that's just not the case. A Tern has tons more Glide than a Boss, but essentially the same diameter.

A Condor is the king of glide and widest diameter disc/dome. A taller dome on the disc also creates an effective wider diameter as the surface is curved to catch more air volume and glide(not lift).

Think of it another way. If you're watching a disc fly, what event would you say marks the end of a disc's glide? I'd say it's when it is no longer 'flying' but is instead turned into its most dramatic fade phase, edge dropping and headed to the ground. If it were an airplane it would have just banked sharply and is heading for a crash. A disc that has plenty of glide either doesn't do this, or delays doing it longer. A disc with incredible glide, like the Discraft Heat, often just stays flat with mostly forward fade and slides to a flat stop like an airplane making a safe landing. That's what Glide looks like, and the defining characteristic is the discs tendency to stay flat and act as an airfoil longer than a disc with less Glide. Disc stays flat (stable) longer = disc can fly/glide longer.

The disc stops gliding when it remains on the ground or goes vertical, the disc will still glide after skipping off the ground. When the disc is in late hard fade it's going to glide less because the disc is no longer flat and parachuting down at an angle, but it will still be gliding in late fade all the way to the ground unless it somehow goes completely vert which is highly unlikely or poor throwing angles for distance in air, like a spike hyzer or roller. A shot that stalls out of forward speed will still glide or parachute down, but not have any lift.

You are trying to compare discs with different wing designs(and spin/speed rates and angles of flight), rather than dome design, and have found a disc/Heat aerodynamically wing/dome designed to match your specific sweet spot with your individual throwing mechanics. Glide design has nothing to do with staying flat or being an airfoil longer, a disc is an airfoil regardless of flying flat or whatever direction. Staying flat will help a disc glide since it's providing max air resistance/parachute to the ground when flat, and staying flat will help lift the disc even while falling forward. The glide during flight is an effect of the disc's ability to stay flat, glide is not causation of the disc's ability to stay flat, but it's glidey characteristic will actually do the opposite and make a disc less stable. A disc with great gliding property/larger dome also just happens to have greater understability given the same wing/rim design.