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[norbs]

Yep call me!

[John]

A more accurate drop method would be to hold the ball with a vacuum cleaner tube and just switch the power off. If the distance wasn't too great the seam could be avoided more often than not and the landing spot could be controlled fairly easily.

[Ryan]

think thats the way forward John!

good second post btw 

[tim2000s]

think thats the way forward John!

good second post btw 

The way forward if you choose to use a cricket ball...

[RossViper]

keep the ball still and swing the bat into it. see how far the ball is displaced, repeate 20+ times, do stats.

If you drop a ball from 1 meter and film it you wont be able to measure the rebound difference, it will not bound very much at 10 ms-1, and a 25 frame rate wont cut it.

good luck...

[tim2000s]

Right then, I've given this a little further thought and the result is the following hypothesis:

Knocking in a bat increases its coefficient of restitution (or blade surface based rebound)

I plan to prove or disprove this theory and the method will be as follows:

Using the following rig, I will drop a 10mm steel ball bearing on to the surface of the bat and measure the rebound. I will start at a distance from the toe and move up the bat in 10cm intervals, repeating the drop 10 times.



The bat will be held as close to the shoulders as possible, which will be marked for repeating the test.

Have completed the 80 or so rebounds, I will then knock the bat in for two hours, and repeat the test in the same way at the same intervals.

By using a new bat that is unknocked in, I will take into account the variance of willow (there will be none) and the variance in handle flex, which will be mostly eliminated by the way the bat is held.

I will publish alll videos on YouTube, and post results in a thread on here.

Using this method, and with a height of 1m, the CoR can be described as the square root of the bounce height, when all measurements are taken in metres.

I may also add a couple of additional bats to see if there is noticable difference in pressing (although this doesn't allow for willow variance).

Any thoughts?

[Buzz]

Any thoughts?

you are nuts?
you have to much time on your hands?
you should spend the time working on your batting?
you should spend more time with your girlfriend?
you should get out more?

but otherwise I am interested in the findings!!

[FvanN]

Right then, I've given this a little further thought and the result is the following hypothesis:

Knocking in a bat increases its coefficient of restitution (or blade surface based rebound)

I plan to prove or disprove this theory and the method will be as follows:

Using the following rig, I will drop a 10mm steel ball bearing on to the surface of the bat and measure the rebound. I will start at a distance from the toe and move up the bat in 10cm intervals, repeating the drop 10 times.



The bat will be held as close to the shoulders as possible, which will be marked for repeating the test.

Have completed the 80 or so rebounds, I will then knock the bat in for two hours, and repeat the test in the same way at the same intervals.

By using a new bat that is unknocked in, I will take into account the variance of willow (there will be none) and the variance in handle flex, which will be mostly eliminated by the way the bat is held.

I will publish alll videos on YouTube, and post results in a thread on here.

Using this method, and with a height of 1m, the CoR can be described as the square root of the bounce height, when all measurements are taken in metres.

I may also add a couple of additional bats to see if there is noticable difference in pressing (although this doesn't allow for willow variance).

Any thoughts?

Love it.... really do... but yes more time with the girlfriend/wife is needed to.. 

[tim2000s]

you are nuts?

Yup.

you have to much time on your hands?

I wish...

you should spend the time working on your batting?

lol. need to go to nets for that... See later point....

you should spend more time with your girlfriend?

She'll be away on business while I undertake the test. It will probably be accompanied by a session with a coach at the Oval...

you should get out more?

but otherwise I am interested in the findings!!

Don't tell her that

[Ryan]

Can't wait to see your findings 

[RossViper]

your hypotheses should be null, but I think you'll be OK this time.

Like I said before, I doubt you'll be able to tell the difference in rebound height with a standard speed camera, but good luck.

Ross

[tim2000s]

your hypotheses should be null, but I think you'll be OK this time.

Like I said before, I doubt you'll be able to tell the difference in rebound height with a standard speed camera, but good luck.

Ross

It's all a bit of fun, and if the result is null, then it begs the question of whether spending a couple of hours knocking in a bat really makes much difference... Maybe I should do a vickers hardness test at the same time?

[RossViper]

It's all a bit of fun, and if the result is null, then it begs the question of whether spending a couple of hours knocking in a bat really makes much difference... Maybe I should do a vickers hardness test at the same time?

Sorry, what i mean is for hypotheses testing you need to test a Null hypotheses, not a directional one, anyway it doesn't matter, like you say it a bit of fun, your not going to publish the results in an journal!!! ;-)

I think the other benefit of knocking the bat in is that it does't brake of course so that might make a difference... ;-)

[tim2000s]

I think the other benefit of knocking the bat in is that it does't brake of course so that might make a difference... ;-)

That raises the question of why doesn't it break, which is why I mention the Vickers Hardness Test pre- and post- knocking in.

With regard to the null hypothesis, the null is that Knocking in a bat has no impact on the coefficient of restitution. Or in other words, we won't see an improvement in surface based rebound using this mechanism and that the reasons for a knocked in bat seemingly performing better lie elsewhere...

[Hit Out or Get Out]

Would the knocking in process not increase the proportional limit of elasticity hence it not breaking so easily?

Have you considered using a snooker ball, the size and mass is more akin to a cricket ball than that of a ball bearing? Good experiment though, looking forward to seeing the results.