Question on sidespin.

[Geometry]

When you hit the ball dead center, initially the ball slides and then the friction of the cloth starts to make the ball roll.

When you hit a shot with center left/right does this effect happen or does the sidespin have some "stabilising" effect that stops the ball go into a rolling state?

 

[Tramp Steamer]

That's a very good question Geo, and it's your very first one. Well done.
Unfortunately I don't have a good answer for you, although I could make a pretty good guess. Anyway, there are lot's of good folks here who can give you the straight skinny on it, so keep 'em coming.

 

[Geometry]

That's a very good question Geo, and it's your very first one. Well done.
Unfortunately I don't have a good answer for you, although I could make a pretty good guess. Anyway, there are lot's of good folks here who can give you the straight skinny on it, so keep 'em coming.

Thanks :smile:.

 

[peteypooldude]

Side spin does stay on the cb longer than center ball or draw,you have to get your stroke speed down pat .Set the balls st8 in 5 or 6 ft apart and shoot a stop shot then move them farther apart and you will know exactly how far it carries ,on a longer stop shot you will prabably have to hit it a half tip low to compensate for friction and you dont have to hit it as hard

 

[oldzilla]

To put in more perspective, just your one question is a tiny grain of sand on the beach of cueball control !

spin, stroke, and speed are the things that make up so much in getting the feel of cueball control. your cueball is your vehicle. with every million balls you hit the better you get to know all the different things you can achieve ! then it's a drive in the park.

 

[Geometry]

Side spin does stay on the cb longer than center ball or draw,you have to get your stroke speed down pat .Set the balls st8 in 5 or 6 ft apart and shoot a stop shot then move them farther apart and you will know exactly how far it carries ,on a longer stop shot you will prabably have to hit it a half tip low to compensate for friction and you dont have to hit it as hard

I understand compensating the frictional effects of the cloth using draw to produce zero spin at collision. Less speed = more draw and more speed = less draw. Less distance = less draw and more distance = more draw.

However, what I don't see is if you hit the cueball with center left/right how the Cueball could ever be in a rolling state with providing the CB still has sidespin. If this is the case, then when using center left/right, the compensation of frictional effect of the cloth would not be needed to send the ball along tangent (although tangent itself would be fractionally changed due to the reduced/increased throw).

 

[woody_968]

The cueball will still pick up forward roll when hit off center. This transition is probably what produces the curve on long shots struck with english.

As an example, when you put right english on a shot when the cueball begins to roll it is spinning to the right. This combination will actually make the cueball curve to the right. Of course it was initially deflected to the left due to the off center hit. But when the curve to the right takes place depends on how hard the shot is truck (determining when the cueball starts to roll). If struck hard enough, or if the distance between the cueball and ob is small enough, the roll may never take effect. Of course this is the case with center ball as well.

So to simply answer your question, no, the sidespin does not over ride the friction of the cloth that produces the roll.

Woody

 

[Bob Jewett]

... However, what I don't see is if you hit the cueball with center left/right how the Cueball could ever be in a rolling state with providing the CB still has sidespin. ...

When the cue ball has only side spin, its axis of rotation is through its poles. When it has only follow/draw, its axis of rotation is through its equator. When it has both, its axis of rotation is through some point between the equator and the pole. You can often see this with the spotted cue ball or with striped balls when the axis lines up just right with a spot or the stripe.

Consider a tilted barrel rolling forward on its rim. It has an axis that is partly up, which means it has side spin, but it also has forward spin, because its axis is not vertical. It can be rolling smoothly (without slipping) on the ground even though it has both kinds of spin.

The general assumption by the physicists who study billiards is that the side spin and the follow/draw can be treated completely independently, and that seems to be what is observed on the table. The ball has no trouble having both side spin and smooth rolling.

Some people try to think of the cue ball as if it were a gyroscope, but that usually leads to false conclusions. Gyroscopes have several really bizarre behaviors that you don't see in cue balls because cue balls have no obvious major axis.

 

[dr_dave]

When the cue ball has only side spin, its axis of rotation is through its poles. When it has only follow/draw, its axis of rotation is through its equator. When it has both, its axis of rotation is through some point between the equator and the pole. You can often see this with the spotted cue ball or with striped balls when the axis lines up just right with a spot or the stripe.

FYI, here's a good video illustrating this:

NV B.10 - Drag spin loss and English persistence​

The general assumption by the physicists who study billiards is that the side spin and the follow/draw can be treated completely independently, and that seems to be what is observed on the table. The ball has no trouble having both side spin and smooth rolling.

Some people try to think of the cue ball as if it were a gyroscope, but that usually leads to false conclusions. Gyroscopes have several really bizarre behaviors that you don't see in cue balls because cue balls have no obvious major axis.

Agreed. There are no significant or practical gyroscopic effects at a pool table. Although, I did try to account for possible gyroscopic effect caused by the interaction of rolling resistance and spin resistance,which could lead to object-ball turn or swerve. The effect is tiny. For more info, see:

http://billiards.colostate.edu/threads/swerve.html#turn​

Regards,
Dave