a question regarding english....

Robert Raiford said:
I think for equal amounts of draw and side on the miscue limit circle (i.e. 4:30 or 7:30 tip contact) to give the highest spin/speed ratio once NR is achieved, it would require an overly generous miscue limit of ~0.7R. A more reasonable miscue limit assumption of 0.5R-0.6R achieves the the max spin/speed ratio closer to 4:00/8:00.

Robert
Click to expand...
True. 0.5R is probably the most tip offset players should try for which would give 4:00/8:00 exactly. (0.5R means that the tip is hitting the cue ball half of a cue ball radius from center which would be 9/16ths of an inch.)

The article referred to earlier is http://www.sfbilliards.com/articles/1998-05.pdf which has some illustrations. The original idea of "lines of hit for constant side spin after smooth rolling" is from Ron Shepard's paper about pool physics which is available at: http://www.sfbilliards.com/Shepard_apapp.pdf
See pages 26-28. The paper has a lot of equations but Ron does a very good job of explaining the practical uses of the theory.
 
Bob Jewett said:
The article referred to earlier is http://www.sfbilliards.com/articles/1998-05.pdf which has some illustrations. The original idea of "lines of hit for constant side spin after smooth rolling" is from Ron Shepard's paper about pool physics which is available at: http://www.sfbilliards.com/Shepard_apapp.pdf
Click to expand...

Great stuff - thanks to Bob and Slide Rule for this.

With reference to the first link, the 'equal eccentricity' circle result is also interesting. But I cannot think of a practical application - perhaps others can?
 
Siz said:
This sounds intriguing, but I am having some difficulty following it - is there a diagram somewhere that you could link to?
Click to expand...



Basically the diagrams look like the side view of a cue ball.

A line is drawn from the support point, where the cue ball rests on the felt. A line is drawn either straight up, which would be a 0 degree slant line, that is no slant.

Another line could be drawn say 10 degrees from vertical. Say leaning slightly to the right. This is the contact point of interest between the cue ball and the cue tip. Contacting the cue ball at the equator, above, or below on this line will have similar effects. The slant line angle is measured from the vertical point at 0 degrees, down to the horizon at 90 degrees. The opposite of normal mathematical convention.

The spin speed ratio is maintained.

I have used these slant lines to change the cue ball angle off of the first contacted rail. The angle is increased or decreased depending if the slant line is to the left or right.

That is, for pocketing an object ball to the left, the cue ball goes right and contacts the first rail. Should you have a slant line of say 10 degrees to the right, slanting right, the natural angle off of the first rail is increased, made wider, by 10 degrees.

In a like manner, the same shot with a left slant line, slanting left, will change the natural angle off the first rail. The natural angle is decreased by 10 degrees.

Slant lines of 20 degrees would have a greater impact. Or at least, I have convinced myself that this is happening.

I also use slant lines for a soft hit banking system.


Hope the above simplifies this somewhat.

I have jotted this post, the night prior to a trip to see my daughter and her family. I will look in again on this thread next Sunday when I return.

I am having a brain fart, posting the diagrams.
 
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Bob Jewett said:
True. 0.5R is probably the most tip offset players should try for which would give 4:00/8:00 exactly. (0.5R means that the tip is hitting the cue ball half of a cue ball radius from center which would be 9/16ths of an inch.)

The article referred to earlier is http://www.sfbilliards.com/articles/1998-05.pdf which has some illustrations. The original idea of "lines of hit for constant side spin after smooth rolling" is from Ron Shepard's paper about pool physics which is available at: http://www.sfbilliards.com/Shepard_apapp.pdf
See pages 26-28. The paper has a lot of equations but Ron does a very good job of explaining the practical uses of the theory.
Click to expand...

I also recommend this. There is much to learn from Ron Shepard.
The article encouraged me to try related thinking.
 
Siz said:
Great stuff - thanks to Bob and Slide Rule for this.

With reference to the first link, the 'equal eccentricity' circle result is also interesting. But I cannot think of a practical application - perhaps others can?
Click to expand...

The credit belongs with Bob Jewett and Ron Shepard. I am a student of pool.
 
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