Good video, but how the hell????

[Sheep]

"pour the coffee"

I've already made my joke about this.. cause nobody really pours anything that way except when your waiter is trying to be polite and not reach to far over your table.


But holy crap.
He pushes his wrist forward at one point... And the disc is like pointing so far down ... like. My shit dont do that. I can't bend my wrist that far forwards at all.

I'm not going to say I agree or disagree with what pete is teaching here.
I like pete's content though.

But when it comes to grip, its the grip for you. Not everyone can push their wrist forward like this.
So discussing where we put it in our hand without looking at the way the body moves is silly. Because I'm sure a majority of us dont have that level of wrist flexation in that direction.

Of course there is gonna be like 1 person who says they do.
And.. I mean, Cool story. you do you.
Cause the rest of us over here struggling.

 

[Brychanus]

[COLOR=var(--text-lighter)] cause nobody really pours anything that way except when your waiter is trying to be polite and not reach to far over your table.[/COLOR]

I was just making my morning coffee doing little motion experiments again.

If I plant my foot and turn a key in the counterclockwise direction, the entire chain from foot to hand through the wrist does the same thing that happens when I literally pour coffee. The posture subtly shifts during the move and the elbow goes "up" with shoulder flexion and abduction on its own. Same thing when I swing a hammer for deadly intent, same way when I watch Simon from a rear view.

~0:29 here:


When I pour coffee, it is not a time to be polite. I want that coffee in the mug. I don't want it to splash. It is time for my morning dose of stimulants. Try to stop me and you get the shoulder. I'm a clumsy oaf, so I am pleased to find that my body knows well on its own how to find the perfect flow of action from foot to arm to instrument to brace up and transmit the whole flow of action through shoulder to hand to wrist to fingers.

If I carry that action through a "release point" I get the thing that gives me the most powerful hammer blows and the most powerful disc releases.

If you instead literally pour coffee like the polite waiter, you will probably feel more forced tension throughout the chain and be working much harder to dynamically stabilize it.

Interesting.

Edit: I just tried the two ("polite" vs. "natural chain") with my 2 year old grabbing my leg trying to pull me off balance. Guess which one worked better?

 

[RowingBoats]

Lol I've mentioned differences in wrist flexibility being huge before and this is a good example. If you have to pour the coffee to your maximum extent, it feels fkn horrendous.

I agree he seems to be pretty dang flexible in that regard, but I am only slightly less so. The middle ground of my range of motion doesn't bind me up and that is probably why I like the pour method, and not any kind of active supination.

 

[Brychanus]

His wrists are definitely more mobile than mine. If I take it too far in any direction of the ulnar deviation version of "pour the coffee" I get wrist binding or some kind of jerk stress rather than that little tendon bounce. I can also overdo my more natural literal coffee pour and cause stress or jerks on one or more joints. Sweet spot matters.

His grip and postural plane when he shows the motions appear very flat and mostly moving around a vertical axis unlike Simon's, which I continue to think is a "lurking variable" in the recent renewed interest in grips here. I'll continue to try to point it out since I know it eludes the eye for many people.

 

[RowingBoats]

I am definitely going to need one of our resident disc physicists to weigh in on his take on gyroscopic precession being in effect while the disc is still in your hand though...

Not arguing, but that seems highly unintuitive to me.

 

[BruisedOoze]

I am definitely going to need one of our resident disc physicists to weigh in on his take on gyroscopic procession being in effect while the disc is still in your hand though...

Not arguing, but that seems highly unintuitive to me.

Sometimes the best way to approach these questions is to turn the question around. Or rather challenge the assumption. Why can't an object in the hand precess? Where does disc wobble come from if the disc can't precess while in the hand?

The basic answer is that the disc creates / has angular momentum while in the hand and you're inducing off axis torque (via the grip and the overall hand movements through space) on an object with angular momentum. These are the requirements for precession.

 

[glassila]

What if I don't drink coffee??!!

 

[Brychanus]

What if I don't drink coffee??!!

 

[Nick Carroll]

I'm in the camp that does NOT think the "pouring the coffee" cue is confusing or wrong. It's a slight movement - or should be - but seems intuitive to me. And IMO you just want to do it enough to where the disc is in the same line as the forearm. Some people may have to do it more than others, but cues are supposed to be shorthand for getting someone to do something - not "how is this not anatomically the most correct cue?" If there's a better cue for "ulnar deviation" what is it?

I think we run the risk of overcomplicating this, though I do think there is value in exploring it to the nth degree. But ultimately people are going to try and pursue the simplest and most effective way of doing something, so the cues should be short and sweet. And only used when needed, instead of doing them unnecessarily.

 

[Brychanus]

Yes, for the sake of simplicity:

I was trying to offer an olive branch to the cue that is simply to point out that literally pouring coffee as an action can contain the good stuff, including the flow of posture and action that ultimately involves whatever degree of ulnar deviation works for you!

Some players' coffee pouring may benefit from tweaking, too.

 

[RowingBoats]

I think we run the risk of overcomplicating this, though I do think there is value in exploring it to the nth degree. But ultimately people are going to try and pursue the simplest and most effective way of doing something, so the cues should be short and sweet. And only used when needed, instead of doing them unnecessarily.

I'm in this camp too. I feel like a lot of the nose angle discussion is getting very confusing as far as what the goal of the whole conversation is.

To me these cues are...to help you learn how to throw nose down... if you...have a hard time throwing nose down.

Now, should you explore multiple ways of achieving a good nose angle and figure out what's comfortable? Sure that is a sane endeavor. But if you truly do this you almost by default are transcending the concept of a 'cue' imo. Literally all of this can be figured out by looking at wtf you are doing to the disc when its in your hand.

Donno what my point is really. I suppose something about the discussion just seems like people are now on a quest for MORE nose down, and you just aren't going to convince me that it really matters for 99% of players whether they are at -1.5 or -4, and you are gonna totally lose me when you start saying you want -9 and beyond lol.

 

[Brychanus]

I'm in this camp too. I feel like a lot of the nose angle discussion is getting very confusing as far as what the goal of the whole conversation is.

To me these cues are...to help you learn how to throw nose down... if you...have a hard time throwing nose down.

Now, should you explore multiple ways of achieving a good nose angle and figure out what's comfortable? Sure that is a sane endeavor. But if you truly do this you almost by default are transcending the concept of a 'cue' imo. Literally all of this can be figured out by looking at wtf you are doing to the disc when its in your hand.

Donno what my point is really. I suppose something about the discussion just seems like people are now on a quest for MORE nose down, and you just aren't going to convince me that it really matters for 99% of players whether they are at -1.5 or -4, and you are gonna totally lose me when you start saying you want -9 and beyond lol.

FWIW I think some people are trying to optimize more than just the nose angle and that discussion interests me personally, but as usual I share the gist of your sentiment here too for practical purposes.

 

[sidewinder22]

Sometimes the best way to approach these questions is to turn the question around. Or rather challenge the assumption. Why can't an object in the hand precess? Where does disc wobble come from if the disc can't precess while in the hand?

The basic answer is that the disc creates / has angular momentum while in the hand and you're inducing off axis torque (via the grip and the overall hand movements through space) on an object with angular momentum. These are the requirements for precession.

I don't think that is true, maybe I'm wrong, but this how I understand it...

While the disc is in our hand we are giving the disc angular acceleration, which is not the same as angular momentum. An object only has angular momentum that can be conserved(precession) when all its particles are spinning in a circle around its axis/CoM. It's not like we have a fidget spinner in our hand and gripping the center/force applied thru the center, but instead we are throwing the fidget spinner by its wing and the forces we apply to it are not acting thru the center.

Wobble is the result of a force/torque induced off axis to the principle axis of inertia before it's spinning around its center/axis. So it ends up spinning on an intermediary axis, instead of precessing around its center like lift causes.

I would think you would feel the disc spinning/slipping on your hand more like a frisbee freestyler for precession to occur, but I don't feel the disc spinning or slipping on my fingers like that.

 

[RowingBoats]

Sometimes the best way to approach these questions is to turn the question around. Or rather challenge the assumption. Why can't an object in the hand precess? Where does disc wobble come from if the disc can't precess while in the hand?

The basic answer is that the disc creates / has angular momentum while in the hand and you're inducing off axis torque (via the grip and the overall hand movements through space) on an object with angular momentum. These are the requirements for precession.

Im not a physicist or even really smart haha. Im a lowly IT Systems Engineer who likes to throw plastic...

Im not sure I agree with this though. At least in the context of what this guy has said about precession in a previous video.

I dont think applying the reverse forces at a 90 degree angle is a factor in nose down throwing while the disc is in your hand. Its just so much simpler than that.

The disc is not gyroscopically spinning and being manipulated by my fingers, at least I dont think that is what is happening.

 

[RowingBoats]

It's not like we have a fidget spinner in our hand and gripping the center/force applied thru the center

Haha this is a way better way to say what I am thinking.

 

[Nick Carroll]

I'm in this camp too. I feel like a lot of the nose angle discussion is getting very confusing as far as what the goal of the whole conversation is.

To me these cues are...to help you learn how to throw nose down... if you...have a hard time throwing nose down.

Now, should you explore multiple ways of achieving a good nose angle and figure out what's comfortable? Sure that is a sane endeavor. But if you truly do this you almost by default are transcending the concept of a 'cue' imo. Literally all of this can be figured out by looking at wtf you are doing to the disc when its in your hand.

Donno what my point is really. I suppose something about the discussion just seems like people are now on a quest for MORE nose down, and you just aren't going to convince me that it really matters for 99% of players whether they are at -1.5 or -4, and you are gonna totally lose me when you start saying you want -9 and beyond lol.

So I think all this is useful in nailing down what to do for each individual. Some people have more ulnar deviation by default, and so forth. Different people may need different cues to get changes to occur, as well. It's just hard to nail down what can be done with certain form changes. Can a change that is supposed to be good, actually be bad? So I'm all in on the exploratory stuff, by the people who can nail down a lot of these details. The rest of us can still be helped by these tests and analysis. Thank you to everyone who does this.

 

[BruisedOoze]

I don't think that is true, maybe I'm wrong, but this how I understand it...

While the disc is in our hand we are giving the disc angular acceleration, which is not the same as angular momentum. An object only has angular momentum that can be conserved(precession) when all its particles are spinning in a circle around its axis/CoM. It's not like we have a fidget spinner in our hand and gripping the center/force applied thru the center, but instead we are throwing the fidget spinner by its wing and the forces we apply to it are not acting thru the center.

Wobble is the result of a force/torque induced off axis to the principle axis of inertia before it's spinning around its center/axis. So it ends up spinning on an intermediary axis, instead of precessing around its center like lift causes.

I would think you would feel the disc spinning/slipping on your hand more like a frisbee freestyler for precession to occur, but I don't feel the disc spinning or slipping on my fingers like that.

I don't disagree with the principle / spirit of what you're saying about free gyroscopic precession, but to be clear I'm talking about precession in the most generalized sense. That is to say any change in the orientation of the rotation axis.

Where I'm driving this has to do with a torque on any body with angular momentum, and the equations that govern rotational dynamics (i.e. Euler's equations). The perpendicular / 90 degree offset effects (cross products) manifest in these expressions. The thing is this applies to non-conservative and non-ideal systems as well, so I don't see free gyroscopic precession being a strictly necessary component in producing a nose up / down effect due to rotation while the disc edge is in hand.

It could be negligible / inconsequential as you say, I don't know, but I'm hesitant to immediately dismiss such effects based on behaviours of idealized systems. Which is why I feel it's worthwhile to challenge the assumptions here. Cows are not always spheres and all that.

 

[sidewinder22]

I don't disagree with the principle / spirit of what you're saying about free gyroscopic precession, but to be clear I'm talking about precession in the most generalized sense. That is to say any change in the orientation of the rotation axis.

Where I'm driving this has to do with a torque on any body with angular momentum, and the equations that govern rotational dynamics (i.e. Euler's equations). The perpendicular / 90 degree offset effects (cross products) manifest in these expressions. The thing is this applies to non-conservative and non-ideal systems as well, so I don't see free gyroscopic precession being a strictly necessary component in producing a nose up / down effect due to rotation while the disc edge is in hand.

It could be negligible / inconsequential as you say, I don't know, but I'm hesitant to immediately dismiss such effects based on behaviours of idealized systems. Which is why I feel it's worthwhile to challenge the assumptions here. Cows are not always spheres and all that.

I think the last point of contact is typically behind the 3 o'clock (closer to 4 o'clock but varies) so the force is directly pitching the disc 180 degrees from it rather than 90 degrees. So if your force is up toward the backside of the disc, it's pitching the nose side down, and vise versa. Maybe it's too simple an idea. Maybe I'm wrong, IDK, just not ready to accept Pete's explanation as the truth and challenging it.

 

[sidewinder22]

Is 66 degrees of disc pivot relative to the contact point enough for a 90 degree precession to occur?

 

[BruisedOoze]

Im not a physicist or even really smart haha. Im a lowly IT Systems Engineer who likes to throw plastic...

Im not sure I agree with this though. At least in the context of what this guy has said about precession in a previous video.

I dont think applying the reverse forces at a 90 degree angle is a factor in nose down throwing while the disc is in your hand. Its just so much simpler than that.

The disc is not gyroscopically spinning and being manipulated by my fingers, at least I dont think that is what is happening.

Sure, not trying to be overly argumentative. I was intrigued by your original inquiry because there wasn't something inherent in the formulism that says no, which I think is interesting in itself. The field is filled with simple and innocuous phenomena with intuitive answers, but proving it is another matter entirely and sometimes with surprising results. And this is one of those things that makes doing physics, well, interesting.

As you say it could be simple, and SW is also bringing up points about is the grip even in a position to do it, or does the disc even have enough time to precess (I'm assuming that's what you're driving at SW with asking is 66 degrees enough?)

It should be easier to answer from a data perspective with people putting IMUs on discs. But I'm not sure if the commercial ones give that much access to the data stream for that part of the throw or even stores it? @sidewinder22 I just saw your video with one so maybe you have a comment on that?