DeadCrab

05-31-2007, 03:03 PM

If you like to set up your shots by positioning your cue along the aiming line, here is a good way to get an estimate of the cut angle (between aiming and impact lines). I use this a lot for angles of 5-20 degrees, especially for long shots.

The perpendicular distance, x, between the aim and impact lines follows the relationship x = h *sin (cutangle)

For a 58 inch cue on the aim line, x = 59sin(cutangle)

This has the very convenient relationship that it simplifies to (approximately): x (in inches)= cutangle(degrees).

So, if you are lining up a long shot, and set the cue down on the aim line with tip near the OB, and the butt end of the cue is 8.5 inches from the impact line, then the cut angle is 8.5 degrees.

For shorter shots, the cue joint can be used as the point to measure from, and:

(2 * z) = cutangle, where z is the distance in inches from the joint to the impact line.

Example: Joint is 9" from impact line --> cut angle=18 deg

In anticipation of the question, "why is that easier than guessing the angle?", it is because a) linear distance in inches is easier for most of us to gague, and b) the hand is a great measuring device. My max handspan is 9", 3.25" across the fingers at the first joint. Hold the cue with one hand, use the known dimensions of your other hand to approximate the distance.

How I translate the cut angle to an aimpoint on the OB is another post.

The perpendicular distance, x, between the aim and impact lines follows the relationship x = h *sin (cutangle)

For a 58 inch cue on the aim line, x = 59sin(cutangle)

This has the very convenient relationship that it simplifies to (approximately): x (in inches)= cutangle(degrees).

So, if you are lining up a long shot, and set the cue down on the aim line with tip near the OB, and the butt end of the cue is 8.5 inches from the impact line, then the cut angle is 8.5 degrees.

For shorter shots, the cue joint can be used as the point to measure from, and:

(2 * z) = cutangle, where z is the distance in inches from the joint to the impact line.

Example: Joint is 9" from impact line --> cut angle=18 deg

In anticipation of the question, "why is that easier than guessing the angle?", it is because a) linear distance in inches is easier for most of us to gague, and b) the hand is a great measuring device. My max handspan is 9", 3.25" across the fingers at the first joint. Hold the cue with one hand, use the known dimensions of your other hand to approximate the distance.

How I translate the cut angle to an aimpoint on the OB is another post.