Does more arc on fh topspin equal more spin.

[MOG]

 

[UpSideDownCarl]

More arc could mean more spin or less speed. When a ball is fast and you see it pulled down to the table despite the speed, that is more spin. When the ball is relatively slow and there is an arc, that could be the result of the ball's lack of speed.

 

[Haito]

https://ttgearlab.com/2017/02/06/performance-indices-the-way-to-evaluatie-blade-by-measurement/
Here is formula how to calculate curve length: https://tutorial.math.lamar.edu/classes/calcii/arclength.aspx
Figure out which arc has lower length (spoiler low arc). With same speed, high arc ball will seem slower.

 

[langel]

If the arc is almost symmetrical, there is almost no spin.
If the distance from the highest point to the landing point is much shorter than the distance from the hitting point to the highest point, than the spin is more.

 

[Brs]

Why don't you get someone to block for you and see if you can make them block off the end. If you can't then your spin sucks with either blade, and vice versa. It isn't the blade making the ball spin.

 

[langel]

Why don't you get someone to block for you and see if you can make them block off the end. If you can't then your spin sucks with either blade, and vice versa. It isn't the blade making the ball spin.

When you look on a masterpiece you glory the master, but for the master himself the instrument really matter.

 

[brokenball]

The formulas for computing arc length are useless until you know what dy/dx is.

There are a couple of things that determine the trajectory. Gravity, air resistance and the Magnus effect. Which is the cross product of the speed with the spin so the arc due to the Magnus force alone is a function of the spin to speed ratio.

Wrote a simulation years ago using Mathcad that used 5 differential equations.
1 x position
2 x velocity
3 y position
4 y velocity
5 rotation speed decay.
The initial values for the above are given and the differential equation will determine the trajectory by integrating them.

Slow balls with no spin will still have an arc due to gravity.
So how of the downward force is due to gravity and how much is due to the Magnus force?
I know.
I can calculate exact times and distances assuming I know the correct air density and gravity at that point.

What is interesting is the video that showed up years ago called "The fastest serve ever".
The Magnus force was strong in that one.
BTW, William Henzel provided me with the high speed 240 fps, version of that video so I could make the calculations.

Strangely enough I could never figure out where to put the "deceptive, disruptive, or wobble" forces.

This is no big deal. The engineers that write the software Dan's nemesis, the Omron robot, have this figured out.

 

[Haito]

I would like to elaborate more on sources I provided in post #3.

I think that spin is influenced majorly by two factors:
- acceleration
- time to accelerate the ball

First one is pretty obvious. But the second one seems to be a bit more complex because there are at least two major factors: contact thickness (major) and gear (minor). When it comes to gear there are 2 pieces that influence that time, mainly sponge hardness and pip structure. The second one I don't want to touch because I have no idea on the matter. The first one is pretty obvious, the softer the sponge, the easier to compress it, easier to get more on the rubber. Blades is a different story though. Author of Exhibit A distinguished two main deflection types, primary and central, and the relation between those two influences how long the ball can stay on the blade. So the short answer would be that more flexy 5-ply wooden looping blades are easier to produce big amount of spin. The long answer is that there can be a blade that is stiffer in general but still allow produce spin if ttgearlab is to be trusted. DHS Long V according has deep hold property according to ttgearlab. I don't understand his theory fully, but I did play with Long V copy and I can attest that looping with it is very easy, so I feel like there can be some truth behind those numbers.

When it comes to which arc indicates more spin, then the answer is both. The arc shows the relation between spin and speed. My friend did an elaborate and long proof in Polish about this (too long and too many words I don't know in English), but basically the faster the ball the stronger the rotation must be to pull the ball down, it also means that the slower the ball the stronger ball can dip with the same rotation. What would be actually meaningful and easier to discuss is how the ball kicks when in contact with the opponent blade or the table itself. The stronger the spin, the stronger the kick. My colleague based that on Magnus effect, sry I am no physicist to translate that properly to English. There should be plenty of hard-headed engineers here though.


Exhibit A: https://ttgearlab.com/2017/02/06/performance-indices-the-way-to-evaluatie-blade-by-measurement/

PS: I think that smashing feels better with stiff stuff because less energy is absorbed by the blade deflection and more energy is transferred to the ball directly. Looping and smashing benefit from opposite blade properties. I don't think you can eat the cake and have the cake at the same time. I would assume that you either play with flexible blade that makes looping easier and swing harder on smashes to compensate or work on technique to loop with stiff blades. As far as I know, pros does both

 

[Haito]

All this suggests I should persevere with the force pro blue, or at a push try (a slightly quicker/harder on bh 7 ply wood) and work on the things that have been pointed out by many.

If you want to EJ some more on 7plies, consults this article: https://ttgearlab.com/2017/02/16/sa...edition-vs-some-7-ply-wood-blades-comparison/

 

[Haito]

Also consider adding to that list one wing stroke switching. Switch between types of stroke on a single wing. For example you can tell your friend to feed you a ball and at the same time tell you how to contact the ball. You can mix in some enderspins. If you already mastered that you can add one more layer two it (which I started doing just recently), by placing the ball anywhere in that wing half (forcing to move more).

 

[Haito]

I do this sometimes already, well often TBH!!

Great, you can also consider extending this exercise to 2/3 of the table width. Also, make sure that someone is watching and controlling your technique. Making sure your shots sound right and you do full swings. 2/3 is bit much for me, but this exercise does help 1/3 of your bullet points.

 

[IB66]

Hi MOG,

you could try playing your stroke, hit the ‘pause real time button’ leg it to the other end of the table, press play and try and block your own shot !!!
but seriously, this is one of the frustrating things I find about Tennis Tennis and other racket sports, not being able to be on the end of your own shots !! So you can actually experience 1st hand what you are actually producing!!
sometimes the best you can get is your playing partners observations !!!

 

[Brs]

is not just as simple as get a blade and rubber and train.

Depends. It is just that simple. Simple can also be boring. So we don't like simple.

 

[Haito]

so shall i get a primorac carbon and just learn to control it?

 

[IB66]

I am going to post some video of me doing basic drill with two blades, wonder if anyone can spot which is which?

Hi,
looking forward to see them, gotta be better than the ones I posted last week!!
I’ll see if I can do a couple as well, D09C v H3 provincial 37 degree v Skyline 3 v MXP/MXS

 

[Haito]

To me they are pretty much identical, but from little clues I see I would say that.
1 - Ma Lin
2 - TFP

Consider loosing you wrist and left arm. In 1st video left arm seems loose, but in the second one it behaves like chicken head (stays in place)
About the wrist: https://youtu.be/4KThMnP3Azs?t=180

 

[UpSideDownCarl]

The things I would say stand out to be noticed are:

1) Watch your feet and how often your heels stay on the ground, this limits the amount you can use your legs and torso to power your stroke.

2) Note how sometimes your training partner has to take a stroke and impart spin because your shot does not have much power behind it.

3) Also, note how vertical (open) your training partner’s racket is when he does just block. If there was a lot of spin that angle could cause the ball to hit the ceiling.

4) Look at the angle of your elbow on your backswing, mid-stroke and in follow-through position and note that the elbow does not change angles at all. The bend in the elbow stays close to 90° throughout the stroke. Also watch the elbow go higher and lower. Most of your FH stroke in these training drills is coming from your shoulder while your elbow and wrist are held pretty tight. This means racket speed is necessarily limited by the limits in the joints that create the most acceleration (elbow and wrist).

Those details could really help you increase spin, power, racket speed while using less effort.


Sent from my NSA SpyPhone from Sector 13D-SR13Z74 Sub Level 29X Fort Meade, Maryland

 

[IB66]

Training video 2!

Is this YMLC or TFP (yasak ma lin carbon or tibhar force pro blue)

I couldn’t see much difference either !!!!!!, guesswork!!!! Says 1)TFP 2) YMLC

And Kuba is correct about your wrist, it looks very stiff, locked in place, relax during backswing and forward swing, let the end of the racket point down rather than up, cock wrist down, tighten fingers and snap wrist up at impact. Then relax again straight after impact for rest of follow through.
far be it for me to advise!!!
if you try just hitting some balls with only a wrist action, no arm or minimal arm movement, no shoulder turn, etc you be surprised how much power can be imparted!! Then when combined with a full stroke the speed and especially spin is increased.

easy said, last week was the first time I had actually watched myself hit balls, so I have a long way to go and improve.

 

[brokenball]

so shall i get a primorac carbon and just learn to control it?

There is nothing wrong with your Samsonov Alpha. Put some Rakza 7 or even H3 Neo on the FH.

I understand the obsession with equipment, but believe me. Being in shape, technique and practicing is much more important than equipment.

The TT manufacturers would like you to think their new magic rubber will solve all your problems but it won't. The TT manufacturers lie and distort.

The coaches here should give this a like.

 

[yogi_bear]

MOG, where's the video?