Joe Bowler
2x Virtual League Champion
Registered: 04/09/09
Posts: 3825
A/S/L: 50s/M/MD
No local tournaments this weekend, so I finally got around to taking some video to calculate my current rev rate, axis rotation and tilt, before making any major changes to my form or release.
The video was just under 6 seconds at 1/8 playback speed, for a total of 0.7 seconds. During that time, I counted 3 full revolutions of the ball. So, if I am calculating correctly, (3 revolutions / 0.7 seconds) * 60 seconds = 257 RPMs.
I also snapped a photo from the video at the point of release. I am just guessing, but it looks like around 80 degrees axis rotation and 10 degrees axis tilt.
Thanks for the tip. Unfortunately, that was the best shot I could get from my entry-level video camera at 60 fps. Movie Maker was helpful in calculating the fractions of seconds.
#173412 - 11/27/1212:50 AMRe: Help Calc Revs, Rotation, Tilt
[Re: Joe Bowler]
B-Hammer
Legend
Registered: 04/19/09
Posts: 1818
A/S/L: 30/M/Bellingham WA
Using the overlay I came up with:
82* of rotation
12* of tilt
If you have a higher resolution image that is more directly behind I can try to get a more accurate reading. It was a little hard to see exactly where your pap mark is.
#173414 - 11/27/1205:31 AMRe: Help Calc Revs, Rotation, Tilt
[Re: Joe Bowler]
Joe Bowler
2x Virtual League Champion
Registered: 04/09/09
Posts: 3825
A/S/L: 50s/M/MD
Thank you, B-Hammer! That was exactly what I wanted to do, to combine the photo with an overlay. I just did not know how to do it.
Unfortunately, I think I would need a higher speed video camera to get a better quality photo. When I first started setting up the video, the tape on the ball was white and ran from my PAP to over my fingers. But, I guess after a few test shots, that was enough for it to get mangled a bit.
Still, I am very happy with the results. I wanted to know my starting point in RPMs, MPH, Axis Rotation, and Tilt before attempting any changes in my form and release. Now I do, thanks!
thanks for that! I believe when I used the overlay my axis tilt is 10deg and axis of rotation is 75deg. this could be +- 1deg. based on the overlay and how i sized it, but, it's close. is the only way to post a photo inline with my reply with a url?
#180109 - 08/11/1301:09 PMRe: Help Calc Revs, Rotation, Tilt
[Re: Joe Bowler]
Joe Bowler
2x Virtual League Champion
Registered: 04/09/09
Posts: 3825
A/S/L: 50s/M/MD
Sorry, I can't really see the tape or PAP very well. But, if the PAP is the intersection of the vertical and lower diagonal line it appears to be 75 degrees axis rotation, and 5 degrees axis tilt.
I learned a lesson after my first effort, and the next time I used brightly colored removable dots instead of tape. See below. The orange dot is my PAP. The yellow dots are to help count the revs. The dots seemed to survive the ball return much better than the tape, and made it easier to recalculate my axis rotation (65 degrees) and axis tilt (15 degrees).
Rather than begging for donations we're asking you to do one simple thing to help keep these forums running smooth:
When shopping for anything on Amazon.com or eBay please use these links to go to the web sites.
This won't cost you a cent!
You'll still get the exact same low prices, deals and free or low cost shipping; it doesn't change anything for you at all! The items do not have to be bowling related; all purchases made through these links help us! Amazon.com and eBay will pay us a small commission for every sale and it's helping us cover the expenses.
BowlingFans.com, BowlingFans, The Right Approach, Kegler's Connection, Tour411, BallBeat, BowlingCommunity.com, BowlSearch.com, and Bowling News You Can Use are trademarks of usrbingeek LLC. All other trademarks and tradenames are property of their respective owners.