【The Geometry of GOLF】 5. Lie angle and Face angle
If the lie angle at impact does not match, the face angle will deviate from the straight, and the deviation is as formula above. In other words, in the case of a sand wedge with a lie angle of 60 degrees and a loft of 60 degrees, if there is a difference in lie angle of 3 degrees, the face angle will change by 2 degrees. If the face angle is off by 2 degrees, it will move about 2 yards to the left and right at 60 yards. If this is a 7-iron with a loft of 30 degrees and a lie angle of 60 degrees, the face angle will deviate by 1 degree if the lie angle difference is 3 degrees. This 1 degree face angle shift is about 3 yards to the left and right at 150 yards away. In case of is a driver, If the loft is 10 degrees and the lie angle is 55 degrees, the deviation of the lie angle of 3 degrees is about 0.55 degrees. If it is 250 yards away, it will be about 1.5 yards off. In other words, the iron aiming at the pin has a greater effect than the driver, and the lie angle difference should be less than 1 degree. In case of putters, A typical putter has a lie angle of about 70 degrees. Also, the loft is generally 3-4 degrees. In this case, let’s calculate how many degrees the lie angle tilts to the left and right with a 10m putt. Since the size of the hole cup is 108 mm in diameter, it will come off to the left and right when aiming at the center when it is off by 54 mm to the left and right. That’s about 0.31 degrees in terms of angle. Assuming that the lie angle is 70 degrees and the loft is 4 degrees, the face angle shifts by 0.31 degrees only when the lie angle changes by 7 degrees or more. To change the lie angle by 7 degrees, a 34-inch long putter will change as the 9.5 cm grip and the ball get farther away. If the position of the ball is 9.5 cm away, the 10 m putt will come off to the left. With a putt, it can be said that even if the position of the ball is about 5 cm away, there is almost no effect.