here is an experiment that we can try out. find a permanent marker pen, find a birdie and then color 4 feathers black with the marker. the ones on 12/3/6/9 o'clock. both in the inside and outside. and then go practice with it. probably need 3 person, two playing, one spotter on the side. then start doing various drills, fast smash, slice smash, hard smash, fast drop, slice drop, reverse slice drop, drives, fast clear, slow clear, sudden slow attacking clear. the job of the spotter then is to see what kind of spinning pattern is associated with each type of shot.
argh. we tried it today. i painted two opposing feathers black with permanent marker, left it dry, and played with it. we only had two person so i had to play and spot at the same time. it was very difficult to spot and play at the same time. firstly because the shuttle flies off so quickly, secondly cause i miss the first fraction of a second. i noticed most of the time, the birdie spins counter-clockwise mentioned. aside from that, the only interesting observation i managed to get is that a fast decelerating clear has this spinning pattern: initially, the birdie doesn't spin that much. almost no spin at all. then when the birdie decelerate enough and loses momentum, it turns around and then starts to fall straight down and spins in the normal counter-clockwise pattern. on a smoother round topped clear, the shuttle spins counter-clockwise from beginning to end. so in other words, the lack of spin actually slows down the birdie quite drastically, and thus create the fast clear that goes all the way to the back, yet suddenly decelerates and drops steeply. to do the experiment right, one really need a 3rd person as a spotter. the other hard part is that as the birdie is always spining counter-clockwise, it is hard to differentiate between fast spin and slow spin.
after reading this thread, i've suddenly taken notice in what you're talking about. i've been using this stroke without even realizing it. the clockwise spin works great with drops from the baseline. plus the motion of your stroke gives the deception that you're hitting the bird in another direction. the decay of the flight is amazing when you hit it properly.
If you haven't played with a plastic shuttle for years try it, and try slicing it !! You won't believe you ever played with plastics!
I notice that some brand of feather birds don't spin at all when you hit them in the air. They just fly like a rocket. Does anyone know why?
hmmm, that reminds me of a shot i managed to pull off i had to admit, it was a fluke because i was off balance but what happened was I tried to clear it and it was going pretty high, but all of a sudden, the moment it crossed the net, it dropped, it just fell straight to the ground (and i'm not sure what happened) my opponent anticipated it as a clear and he moved back but dove forward to try to return it but he was too far back. everyone was confused, i was too -_- heh.... maybe it had something to do with the spin of the bird...?
nah, it didn't go that high it was just a regular clear - in the middle of the space between top of net to the ceiling, high enough to go over the opponent's head but not high enough to be considered out
I think its time to do kwun's test with a video camera! I have one but there's no one to experiment with. :crying: Maybe by feeding the taped sequence into a video edit program we can deduce how fast the shuttlecock really is spinning.
if someone can do that, it should be easy to do. we would need one reference point on the shuttle however, not four, as kwun had mentioned earlier. perhaps paint two consecutive feathers black. then with the video, all we need to know is how many frames per second the video is shot at, and then we can determine the rotational speed of the shuttle at various points in flight!
Interesting subject guys Is anyone planning to do the above test?? I would if I had a good camera...maybe I just have to ask 'round a bit..
how does spinning a birdy or a ball change its flight path? Hi, how does spinning a birdy slow it down, or adding topspin to a ball make it drop, or adding adding slice or spin make the ball travel in such a bizarre pattern. Like in ping pong when you hit an extreme side spin shot you can make it curve a rediculous amount? Thanks
[font="]Shuttle slow down due to the aero dynamic of the cone shape. Since the feathers are stacked in an angle, the air passes by the shuttle and produces a force on the shuttle to cause it to spin. During this process, the forward momentum of the shuttle transfers into angular momentum. This is why shuttle slow down when it spin. Also, the cone shape of the shuttle produces a drag. This drag is actually the force to slow down the shuttle. The reason badminton shuttle spin is to produce a good flight path just like a bullet fired from a rifle. If the object dose not spin, it (shuttle, bullet etc.) will tumble and you will not be able to strike the cork of shuttle. Badminton shuttle is not a ball. You can not compare the side way curving of spherical objects to the projectile motion of shuttle.[/font]
Thanks.. btw, how come when u slice it seems like the birdy flies faster than goes slower, wat causes this? does slicing slow down the spin, so it causes more turbulence and more air resistance?? I'm right handed btw, because i saw the thread by kwun about slice spin, and its counter clockwise, so a right handed slice would induce clock wise spin? so that it slows it down causing the sudden drop?? Does this mean a left handed spin makes it go faster because of faster spin???? Thanks
First, at a given shuttle velocity, there will be an optimal spinning speed (revolution per sec or rev. per min. depend on your measurement). If the shuttle spins faster than the optimal speed, the force act on the shuttle will slow it down and due to the cone shape of the shuttle. However, this force will also act on the shuttle to slow it down. If the spinning speed of the shuttle is slower than the optimal spinning speed, the shuttle will spin faster and shuttle will slow down ( I wish I can draw a force diagram to show you). Since the drag coef. on the shuttle is pretty high (assumption on my part. I have nothing to test right now), the shuttle will be slowing down all the time. That means the shuttle’s optimal spinning speed decrease all the time. This will slow down the shuttle further more. I do not have shuttle to test on what direction does a tournament shuttle should spin. So I have to make some assumptions. Let us assume the correct spinning direction is clockwise. If you hit a slice and produce a counter clockwise spin, shuttle will be forced to spin clockwise once it start to travel other direction after contact. That will force the shuttle to slow down. If you slice the shuttle and produce no spin, the shuttle will tumble and have higher drag coef. It will slow down the shuttle even faster. If you slice the shuttle and made it spin clockwise, it will not slow down as much since it is already spinning and close to optimal spinning speed. Actually, badminton is a very good sport to lean aero dynamics. If you ever have a chance to take a course in AD, there are so many things apply to this sport.
The spin that a slice imparts is different from the ordinary axial spin of a shuttle. The slice makes it spin in a tumbling way (like a tumble net shot). This produces a lot of extra air resistance, and therefore the shuttle will slow down. So on a slice drop shot, you can hit the shuttle fast, but it will slow down as it approaches the net.
Thanks for the detailed and very interesting discussion, but I am not sure whether I follow all of this. Therefore a simple question: * Is there a difference between clockwise and anti-clockwise spin? As a right-handed player I put heavy slice into my attack clears (hitting in a clockwise motion). It seems to me that this lets me strike a mucher faster shot that nonetheless does not go out at the baseline. I use a counter-clockwise motion to play a deceptive cross-court dropshot hit from left-of-the-head into the righthand corner. I get the counter-clockwise hitting action by changing the angle at which I hit the shuttlecock using a last moment grip change. This makes the motion identicial to my longline clear. My impression is that the shuttle moves much faster than with a straight zero spin shot and drops down faster. * Does all of this make sense or are my impressions simply incorrect? Thanks for the information. Best regards, Frank
