snap vs. torque/ am i doing something wrong?

[black udder]

I don't think you can throw a putter 280' without snap. It sounds like you're talking about what Blake calls "snap" and "big snap". The 350' putter toss being big snap and that being something that a lot of folks never get due to the timing requirements.

I wasn't clear enough, I was more talking about a change in snap. The difference between a 200' and a 280' putter throw could be some snap, but the difference between a 260' and a 280' putter throw probably isn't snap related.

Yeah, with ya

 

[JR]

Torque can equal wobble=less stability

just want to clarify again that the torque i'm talking about is good torque, not bad. just referring to the energy and velocity in the throw. my clean throws were turning over more.

anyway, i'm done with this for a while. at least until i get the hang of that new, more hip-priming x-step i'm working on.

I tried the same last summer if I understand you correctly. If by using the hips more to try to simulate the 360 you're meaning torque from the leg pivot and hip twist. I'd use different terms to avoid mixing up definitions as torque is evident in many parts of the throw if one uses the physics definition.

What I think you're trying to say is to turn back more with the legs and especially the hips and concentrating on twisting the hips extra hard. And during the x step using a larger swing in degrees for the step direction and the enlarged motion range with the hips due to max twist left at the hips and the possible curved x step. That is the latter part of the 360 run up. You said that you were keeping the disc in a line and that's different from a 360 which already has momentum from the first half of the 360 where you start the arm motion. The same goes for spinning around with the legs and twisting with the hips. But what you're probably doing does give a little more D. But don't be discouraged by the lack of accuracy. That's just something that's common for all max D efforts be it absolute or golf D.

You were attributing more motion range from the hips for more D and that would be correct for a bent elbow throw according to Öystein Carlsen's thesis and measurements. He attributed the range of motion of the elbow to D. So the farther back you start to move the elbow the more D you have. And that's where a 360 has a clear advantage considering it's got about 50 % more range and time to accelerate with an immobile and loose arm. Leaving all the available power to be used for a quick acceleration late in throw=generated force.

What you're seeing is correct because more speed and spin on the disc can be generated by having the legs and torso spinning around in a circular motion than running straight. The same goes for the whole arm starting to move quickly to the right with the shoulder turn reaching best speed just a few inches short of the elbow opening up fully. Although that applies more fore wrist snap which increases 10 % to the speed of the disc and 40 % more spin for good players. That wrist snap or wrist extension occurs thanks to the change in the motion of the arm's direction after the elbow has chopped straight. Then all the created momentum is moving the only body part that can move. The wrist.

 

[readysetstab]

yes, i think that was a lot more clear than my explanation.

i probably wasn't very clear about using two different techniques during this thread either. when i started the thread, i was referring to some experimentation with bent elbow (exaggerated motions), from which i was able to generate a lot of extra snap due to the whip action from the elbow toward my hand. i didn't have a lot of control over it so i decided to hold off for a while until i'm done with tournaments for these next couple of months.

the other technique i used was the one i talked about a few posts ago that you were also referring to. your description of it was better than mine, so i trust that you understand exactly what i'm talking about. combining the two techniques will be difficult, at best. that's why i'm only focusing on the extra hip motion right now. i'll have a month or more free from tournaments in june and i'll work on combining everything then.

there's definitely a lot of potential distance to be gained here. i just need to work on it a lot.

 

[JR]

I see no problem whatsoever with initially challenged accuracy and consistency while learning. It happens with more golf related shots and their form changes too. Max D is just inherently less accurate once you lose eye contact. I'm not knocking other aiming methods because I advocate using every method simultaneously. With enough practice limited accuracy and repeatability will come and it can be good enough to be used on some shots so it's a worthy goal. If there aren't more important things in the line before this. Although the physics is the same you don't need that extra D on shorter drives so I really agree with Stokely about using two different forms for long drives and placement shots. Which for me means not trying to maximize leg or hip twisting at the reach back. But for aiming with the feeling of the added weight of the disc from acceleration late in the throw needs a lot of power. There it is a good idea to use a lot of lower arm power but it is challenging indeed at least for me to keep the wrist properly oriented. Even more so when tired. But I've got injuries and anatural physiology after surgical alteration in my arm so YMMV.

 

[readysetstab]

Although the physics is the same you don't need that extra D on shorter drives so I really agree with Stokely about using two different forms for long drives and placement shots.

that's what i've been doing lately. i've slowed my normal "walk-up" down even more to focus on control (under 370ish), and then for big throws (370ish+) i use the other run-up/reach back. its working out pretty well. i'd say stokely got it right.

 

[jdizzle3id]

Let's say you throw right hand back hand(i.e. spinning clockwise from the top). The left side of the disc will have a greater speed relative to the ambient air than the right. Given a "domed" top, the left side of the disc will have a greater aero-dynamic lift than the right side due to fluid-dynamics laws(think airplane wing and think understable). I assume a "more overstable" disc has a flatter top, more rim weight, and a shape that would cause the rotational velocity to slow before the linear velocity(i.e. a sharper rim). The flatter top will allow for less aero-dynamic lift on the left side in comparison to the right, a larger rim weight would require a greater aero-dymamic force to offset the rotational inertia/momentum of the disc, and a sharper rim will allow for the rotational velocity to slow before the linear velocity(less friction). This is my theory on over stable disc dynamics. Please let me know if you think differently and your reasoning behind it. And too sum it up, I think the greater spin to linear velocity ratio you put on a disc, the more understable it will act.

 

[JR]

Me and several others here have experienced the opposite. I leave the science of this to those that know it better Like Bradley, Blake and a professional physicist JHern.

Also more spin with the same linear velocity with a tilted flight is gonna maintain the tilt longer. At lower linear speed it remains tilted until flexing out of an anny which means less lift for longer time meaning dropping faster. Or a hyzer won't tilt even more until later and not dropping as quickly. Just observations from real world experience. Take empiricism for what it's worth as scientific proof or in other words a little salt in science is always healthy.

 

[cmlasley]

I disagree, but (again) only from an amateur's perspective. My basic theory is that the gyroscopic properties have a greater effect on disc dynamics than the change in lift from the rotation itself.

The left side of the disc will have a greater speed relative to the ambient air than the right.

I don't think the rotational speed has any effect on the lift - I think it only counts in the disc's vector of travel.

Given a "domed" top, the left side of the disc will have a greater aero-dynamic lift than the right side due to fluid-dynamics laws(think airplane wing and think understable).

Ignoring the dome (because it is equal on both sides), again I think lift will be equal because the relative speed of both sides of the disc is equal in the vector of the disc's travel.

I assume a "more overstable" disc has a flatter top, more rim weight, and a shape that would cause the rotational velocity to slow before the linear velocity(i.e. a sharper rim). The flatter top will allow for less aero-dynamic lift on the left side in comparison to the right, a larger rim weight would require a greater aero-dymamic force to offset the rotational inertia/momentum of the disc, and a sharper rim will allow for the rotational velocity to slow before the linear velocity(less friction). This is my theory on over stable disc dynamics. Please let me know if you think differently and your reasoning behind it. And too sum it up, I think the greater spin to linear velocity ratio you put on a disc, the more understable it will act.

Okay. I'm sort of following you here, in that the shape of the wing and the weight distribution effect the precarious balance between the forces created by the rotation itself (gyroscopic or as you put it, rotational inertia) and the motion of the air over the wing(s) (aerodynamics).

As I see it, the gyroscopic properties of a spinning disc help to stabilize it, keeping the wing level with the ground like a top. As long as the wing is roughly level and at enough speed to get lift, the disc will go straight.

Here's where my theories break down. I can't really clearly conceptualize the involved forces: Somehow, every disc has a cruising speed (which is a range, of course). Above this cruising speed, the disc turns right when thrown RHBH. Below this cruising speed, the disc turns left when thrown RHBH. More spin will counteract both of these properties, keeping the disc straight.

If I need to throw a really sharp hyzer, I throw with less speed than the disc needs to attain its cruise speed (and usually roll my wrist under, creating beneficial off-axis-torque). Because of this, I often throw hyzers with discs with high cruise speeds (Predator).

For turnovers, the opposite happens. I am more successful throwing with less spin and more speed. I get less spin by using a slightly different form (the disc is further from my body through the pull), and I often add a touch of off-axis-torque in the other direction.

Before I turn into JR, I'll sign off. Again, this is all my amateur opinion based on my observations, my very elementary understanding of the potential inputs and outputs involved, and my constant reading of internet message boards. I have no training (I'm an attorney, not an aerospace engineer).

You sound like an engineering student to me. I'll have to think about your post and come up with some questions.

 

[JR]

Before I turn into JR, I'll sign off.

:-D Oink! the Roc.

 

[cmlasley]

Before I turn into JR, I'll sign off.

:-D Oink! the Roc.

Boo-yah! :mrgreen:

I was just discussing this whole thing with my wife (and we were theorizing whether the disc is one wing or two) when my 2.5 year old son interrupted me and said, "It's spinning around because it's spinning around, because it's spinning around." I thought that was a circular argument.

 

[JR]

Before I turn into JR, I'll sign off.

:-D Oink! the Roc.

Boo-yah! :mrgreen:

I was just discussing this whole thing with my wife (and we were theorizing whether the disc is one wing or two) when my 2.5 year old son interrupted me and said, "It's spinning around because it's spinning around, because it's spinning around." I thought that was a circular argument.

Unless it's not PDGA legal like a Quest AT disc that got pulled from the legal status by the PDGA. Then it's circular and with some bits chopped off so that it fits the result that's been arrived at before studying the phenomenon. Like so much "science".

 

[cmlasley]

After further reflection, it seems that the spin has to effect the aerodynamic forces, else how do you explain the direction of turn into a headwind or over the disc's cruise speed?

 

[JR]

After further reflection, it seems that the spin has to effect the aerodynamic forces, else how do you explain the direction of turn into a headwind or over the disc's cruise speed?

for a RHBH throw the right side of the disc has a little less friction from the air than the left side.

 

[cmlasley]

for a RHBH throw the right side of the disc has a little less friction from the air than the left side.

Wouldn't that make it turn left into a headwind for a RHBH?

 

[JR]

for a RHBH throw the right side of the disc has a little less friction from the air than the left side.

Wouldn't that make it turn left into a headwind for a RHBH?

I'd much rather leave the whole picture to be explained by a physicist. From hearsay with questionable recollections it's a minor effect and there are a whole bunch of forces acting on the disc. Some of the forces oppose each other and act differently and switch which force is stronger depending on the flight speed. So things get reversed from flipping at high speeds to fading at low speeds.

So the answer is depends but probably not too much and not that often.

 

[Olorin1]

for a RHBH throw the right side of the disc has a little less friction from the air than the left side.

I don't think this is correct. This has been passed on via discussion boards and thus elevated to the level of fact, but it just doesn't hold up scientifically. See this DGCR thread on the Physics of disc flight. Here's the relevant part:

"1. The frictional forces in opposition to the spin imparted by torque are, from my understanding, nearly negligible. If they were significant, this would cause the disc to stop spinning in its flight." by Rameka

I'd add to this that the disc is spinning, a gyropsopic wing. The point at the left side with added velocity is angular velocity added to forward velocity. The physical point is very small, then it rotates, plus the velocity increases the angular velocity NOT the forward velocity. The only area that might get any friction is the small point on the left edge that's as thick as the outer edge. So in summary, I think Rameka is correct that the friction is very negligible. Wind tunnel tests by Dr. Potts of Discwing also confirm this.

You can read more of a current discussion of the Physics of Disc flight and get links to helpful articles by Potts, Hummel, and others at DGCR.

 

[JR]

for a RHBH throw the right side of the disc has a little less friction from the air than the left side.

I don't think this is correct. This has been passed on via discussion boards and thus elevated to the level of fact, but it just doesn't hold up scientifically. See this DGCR thread on the Physics of disc flight. Here's the relevant part:

"1. The frictional forces in opposition to the spin imparted by torque are, from my understanding, nearly negligible. If they were significant, this would cause the disc to stop spinning in its flight." by Rameka

I'd add to this that the disc is spinning, a gyropsopic wing. The point at the left side with added velocity is angular velocity added to forward velocity. The physical point is very small, then it rotates, plus the velocity increases the angular velocity NOT the forward velocity. The only area that might get any friction is the small point on the left edge that's as thick as the outer edge. So in summary, I think Rameka is correct that the friction is very negligible. Wind tunnel tests by Dr. Potts of Discwing also confirm this.

You can read more of a current discussion of the Physics of Disc flight and get links to helpful articles by Potts, Hummel, and others at DGCR.

Err without having read those links I don't see anything that you wrote that contradicts what I said. Like I said the difference is small. I used the the words "...a little less friction...".

 

[Olorin1]

After further reflection, it seems that the spin has to effect the aerodynamic forces, else how do you explain the direction of turn into a headwind or over the disc's cruise speed?

for a RHBH throw the right side of the disc has a little less friction from the air than the left side.

In the context of when JR said this my point was that there is such a negligible effect from friction that it has no effect on the aerodynamics and doesn't cause a disc to turn right.

When people talk about this effect of friction I think they're envisioning the affect of wind over the length of a wing when any friction would be only be at a very minute point on the tip of a disc's edge. This tiny point cannot have any associated Bernoulli affects (lower pressure from higher speed air) because the surface area is too small.

 

[JR]

After further reflection, it seems that the spin has to effect the aerodynamic forces, else how do you explain the direction of turn into a headwind or over the disc's cruise speed?

for a RHBH throw the right side of the disc has a little less friction from the air than the left side.

In the context of when JR said this my point was that there is such a negligible effect from friction that it has no effect on the aerodynamics and doesn't cause a disc to turn right.

When people talk about this effect of friction I think they're envisioning the affect of wind over the length of a wing when any friction would be only be at a very minute point on the tip of a disc's edge. This tiny point cannot have any associated Bernoulli affects (lower pressure from higher speed air) because the surface area is too small.

I see. I wasn't trying to explain the whole picture I just dropped a tidbit.

Bernoulli is something I leave to the professionals because of what I read in wikipedia about parasitic drag and following the links. There are too many occasions when the Bernoulli principle doesn't apply to wings. And the stuff I read weren't even talking or rotating objects like discs. That's way out of my league. Besides normally for aircrafts Bernoulli is more important because much of the stuff really kicks in at about 220 MPH. And below that the effects diminish greatly.