I challenge you to a match - me and my finely-tuned racquet and minimal practice against you and your many hours of drilling.Useless gibberish.... I'd rather go hit 1k balls and hone my skills.
I = SW - M(R^2 - 20R + 100) + MR^2
@frear I still cant help you with the 20MR - 100M but I just got me a new racket. I wanted to add just a little mass and the best feature of the racket was how fast I could move the racket through the ball. I wanted to increase mass but not SW any more than I had to so I added 7 g at 6 o'clock. I loved the result. Just out of curiosity I wanted to check the MgR/i value and I used this link http://www.racquettune.com/MgR_I/.
I think I can measure the swing time (period) and length with exceptional accuracy and no math using the link. Long story short my time for 10 swings was 13.72 sec, axis of 64 cm, and a balance of 32 cm. That gave me an MgR/I of 20.97. I was very surprised.
I challenge you to a match - me and my finely-tuned racquet and minimal practice against you and your many hours of drilling.
LOL Ya think not? Think again - http://www.racquettune.com/MgR_I/The guy didn't (won't, probably) add a mgr/I tool, and I perfectly see his point, but I won't complain about that until I'll have proved it
My advice is to ignore anything I posted prior to 2010 or so. Prior to that I was just getting into the experimentation process of figuring out how the physics of racquets and strings work. You've probably seen the thread below, but it's a good place to start if you are serious about learning how to fine-tune a racquet for high performance:Thanks for taking the time and answering. That's now so obvious that I must say it's time to refresh my math..
Since you were so kind, I would take advantage to further ask you if it's to consider deprecated the steps 6-8 of your 2006 guide, ie finding the r' to add mass in order to optimize the plough-through.
I have found it possible to achieve both goals, but I should add a 16 full grams at the throat, which I'm not convinced of doing, and it clearly is quite a higher place than the 7", here often referred as the optimal location (I couldn't find any reference to support this though..).
Thank you.
@frear I still cant help you with the 20MR - 100M but I just got me a new racket. I wanted to add just a little mass and the best feature of the racket was how fast I could move the racket through the ball. I wanted to increase mass but not SW any more than I had to so I added 7 g at 6 o'clock. I loved the result. Just out of curiosity I wanted to check the MgR/i value and I used this link http://www.racquettune.com/MgR_I/.
I think I can measure the swing time (period) and length with exceptional accuracy and no math using the link. Long story short my time for 10 swings was 13.72 sec, axis of 64 cm, and a balance of 32 cm. That gave me an MgR/I of 20.97. I was very surprised.
My advice is to ignore anything I posted prior to 2010 or so. Prior to that I was just getting into the experimentation process of figuring out how the physics of racquets and strings work. You've probably seen the thread below, but it's a good place to start if you are serious about learning how to fine-tune a racquet for high performance:
http://tt.tennis-warehouse.com/inde...erformance-ii-mgr-i-data-for-atp-pros.387805/
LOL Ya think not? Think again - http://www.racquettune.com/MgR_I/
All you need to measure is balance and hang point accurately and SwingTool will give you the period.
Thanks for that link, my racquet has a value of 21.07 . Purely by accident over a year and a half of adding and subtracting weight. I could have saved a lot of time@frear I still cant help you with the 20MR - 100M but I just got me a new racket. I wanted to add just a little mass and the best feature of the racket was how fast I could move the racket through the ball. I wanted to increase mass but not SW any more than I had to so I added 7 g at 6 o'clock. I loved the result. Just out of curiosity I wanted to check the MgR/i value and I used this link http://www.racquettune.com/MgR_I/.
I think I can measure the swing time (period) and length with exceptional accuracy and no math using the link. Long story short my time for 10 swings was 13.72 sec, axis of 64 cm, and a balance of 32 cm. That gave me an MgR/I of 20.97. I was very surprised.
Just using a metric steel tape measure. It does not matter if you use the top string or some other string. I don't use the TW method to support my racket though I use cup hooks in the end of a 1x4 board. If the racket slides back and forth on the pencils you will have errors.Being a complete dunce with anything mathematical (languages are my thing) how do you measure the pivot point in the link above? Swings from the top string as in the TW swing weight measurement tool?
I was adding weight to my new racket new stick at 6 o'clock and quite by accident came up with what I liked at 20.97 I think. The big benefit of changing the weight at or very near the COM is it will not change the balance and you know the hang point does not change. If you add weight at the top of the grip you may have to check the balance when adding or taking off weight.Thanks for that link, my racquet has a value of 21.07 . Purely by accident over a year and a half of adding and subtracting weight. I could have saved a lot of time
There are plenty of instances where weight is placed at the top of the handle. P1 does it on novak djokovic's frame:Lool..assuming you guys lived in relative proximity and can actually play, what would it actually prove? Nothing other then a better player on the day won or one of you is simply a much better tennis player. However out of curiosity, is anyone aware of this formula being used by anyone customizing in the professional ranks? And if so, how did you come about this information?
Use RacquetTune MgR/I (http://www.racquettune.com/MgR_I/.) Measure your balance and hang point accurately and let SwingTool measure the period. Multiple the period from SwingTool by ten and you should be good to go.
In SwingTool you need hang the racket, hit preview to make sure the camera is looking at the racket, swing the racket and hit start. After 15 periods it will tell you the average time. Multiply by 10 and your done. Mine always come up to the hundredth of a second (for ten swings) and +/- 0.02 seconds error (after multiplying the error +/- 0.002 by 10.)Irvin, thanks for the reply, how does one measure the period from teh Swing tool?
I agree that accurate timing is not easy. I have found that using an internet stopwatch is not accurate enough, since other background processes slow it down - I use the stopwatch on my iPhone.I have been monitoring and implementing the theory behind MgR/I and although I am by no means an experienced player, I must admit that I have enjoyed the search and play around. Also the results have been satisfactory to say the least. Lastly a huge ge respect on all that devote theor time to post here their resewrch and findings.
My only comment is that i don't feel confident on the ways to measure MgR/I accurately. It is an output of certain variables in any way way you measure it - SW via SwingTool or a hand stopwatch - when ch both have margin errors. Any deviation or rounding causes big jumps in the output of the MgR/I. For instance i have used xls and Swingtool and got 20.99, and by using the Racketune the time for the 10 swings i used was 13.70 which on my racket specs gave me 20.66. If my timing was 13.79 it would have been 21. That 9 miliseconds could have been an error on my behalf....or not.
Any suggestions/method to make results less "volatile"?
I agree that accurate timing is not easy. I have found that using an internet stopwatch is not accurate enough, since other background processes slow it down - I use the stopwatch on my iPhone.
I measure 20 swings. Then repeat the 20-swing measurement at least a couple more times, until I'm getting reproducible results. I can usually get the times reproducible to within +/- 0.02s , which would mean +/-0.01s for the 10-swing time.
You may be able to reproduce your time within 0.02 seconds but I doubt it for 20 periods. Getting an accuracy of 0.02 seconds I'll never believe.I agree that accurate timing is not easy. I have found that using an internet stopwatch is not accurate enough, since other background processes slow it down - I use the stopwatch on my iPhone.
I measure 20 swings. Then repeat the 20-swing measurement at least a couple more times, until I'm getting reproducible results. I can usually get the times reproducible to within +/- 0.02s , which would mean +/-0.01s for the 10-swing time.
Well, since SwingTool calculates swingweight right from the same data, I'd say just pick that SW number from SwingTool and use it in your excel.In SwingTool you need hang the racket, hit preview to make sure the camera is looking at the racket, swing the racket and hit start. After 15 periods it will tell you the average time. Multiply by 10 and your done. Mine always come up to the hundredth of a second (for ten swings) and +/- 0.02 seconds error (after multiplying the error +/- 0.002 by 10.)
Definitely the strings when thhe ball goes out, more than the racquet!Completely agree. Us damn humans can mod racquets to feel right, but that does not guarantee that we can hit the ball well because of a lot of factors that make us human (like lack of sleep, no focus, etc.) It just means we can't look at the racquet when we hit the ball out.
Thanks for taking the time and answering. That's now so obvious that I must say it's time to refresh my math..
Since you were so kind, I would take advantage to further ask you if it's to consider deprecated the steps 6-8 of your 2006 guide, ie finding the r' to add mass in order to optimize the plough-through.
I have found it possible to achieve both goals, but I should add a 16 full grams at the throat, which I'm not convinced of doing, and it clearly is quite a higher place than the 7", here often referred as the optimal location (I couldn't find any reference to support this though..).
Thank you.
Thanks for taking the time and answering. That's now so obvious that I must say it's time to refresh my math..
Since you were so kind, I would take advantage to further ask you if it's to consider deprecated the steps 6-8 of your 2006 guide, ie finding the r' to add mass in order to optimize the plough-through.
I have found it possible to achieve both goals, but I should add a 16 full grams at the throat, which I'm not convinced of doing, and it clearly is quite a higher place than the 7", here often referred as the optimal location (I couldn't find any reference to support this though..).
Thank you.
Here you find it:Frar may i ask if you can post a link to this 2006 guide please?
Tks
I got almost identical resutls from both methods. My xls and racket tune. Obviously this is dependent on use of the same variable (period from Swing Tool), which since it is a machine calculated and not hand/eye coordination result, I trust more as not necessarily 100% correnct but with significnatly lower margin error.
Here you find it:
http://tt.tennis-warehouse.com/index.php?threads/how-to-set-your-racquet-up-like-an-atp-pro.83285/
But as the author him/herself stated, it has to be considered obsolete.