Nord wrote:I use 14lbs with the True Motion.
Okay, That worked out good I was based on 14lbs.
So how do you calculate speed and revs?
For the speed measurement, I used a IPhone/Ipad app called "Bowling ball Speed" (aka:Bowl Speed) you need someone to work it while you bowl or use with a video it's pretty accurate.
You input ball weight and then you use it to time the ball from foul line to when it hits the pins and it gives you speed of each roll, Average speed, release speed, pin contact speed and impact momentum.
ballspeed.jpg
The way I calculated the revs is, I guess you'd call it the Clock method.
It uses counting 10 frames of the video & how many hours the ball turns (1 rotation = 12 hours).
Starting from the first frame after the fingers leave the ball, You count how many hours of clock time your tracer tape covers in 10 frames (I watched your finger holes since no tape).
Then multiply the number of hours covered in those 10 frames by 15 and you’ll end up with your initial rev rate.
This is the formula used for calculating rev rate using video :
Video cameras capturing 30 frames per second (standard NTSC video format used primarily in North America): hours per 10 frames * 15 = RPM
In your video you had 8-9 "hours" for the 10 frames after your fingers left the ball, So 8*15= 120 rpm and 9*15= 135 rpm
There are 4 different methods for calculating Rev's, I compared them here:
viewtopic.php?p=99462#p99462
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