What is the difference between center of gravity and center of mass and how to find it on a putter

The terms center of gravity (CG) and center of mass (CM) are often used interchangeably, especially in golf, because in most cases they are effectively the same. However, there is a slight technical difference:

•Center of Mass (CM) is the point where the mass of an object is evenly distributed.

•Center of Gravity (CG) is the point where the gravitational force acts on the object.

In the context of golf putters, CG and CM are essentially the same point since the gravitational field is uniform across the putter. Both terms describe the point where, if you could balance the putter perfectly on that spot, it would be stable without tipping. For putters, this point is crucial for ensuring that the sweet spot aligns with the putter’s balance and stability.

Finding the CG/CM on a Putter Face in a 2D Space

To find the CG/CM on the 2-dimensional space of a putter face, follow these methods:

1. Suspension Method (Practical Approach)

• Suspend the putter by attaching a string or holding it by different points along the top edge or sides of the putter head.

• Draw a line vertically downwards from each suspension point. Where these lines intersect will be the CG/CM of the putter head.

• This gives you a good estimate of where the CG is located in a 2D plane on the face.

2. Balancing on a Sharp Edge (Simple DIY Method)

• Place the putter face down on a thin, stable edge (like a ruler’s edge) or on your finger.

• Shift it around until you find the point where it balances evenly without tipping.

• This point on the face indicates the approximate CG/CM.

3. High-Speed Camera and Ball Launch Analysis (Professional Approach)

• Using a launch monitor like the Quintic Ball Roll system, you can analyze ball speed, spin, and direction on impact across the face.

• By comparing putts from various spots on the face, the point with the least deflection and twist will indicate where the CG is located. This is typically used in professional fittings to determine the CG more precisely.

Why It Matters in a Putter

Identifying the CG on the face is essential because hitting it ensures a pure roll with maximum energy transfer, minimal twist, and consistent distance control. If the CG is off-center relative to the sweet spot, it could mean that the putter design needs adjustment for ideal performance.