I recently purchased a Flightscope and am confused on something.. Can someone explain why a clubpath number would be different from the calculation of the HSP number + or - the AA? Shouldn't that be an exact equation everytime?
Think of a typical plane board resting on the ground, and the clubhead swinging on that plane.
The direction of the baseline (where the bottom edge points to) is the HSP. The angle up from the ground to the plywood is the VSP.
Think about an extreme case where the plywood is only 10 degrees up from the ground and you are looking at it from the typical DTL view. In other words, shallow as hell.
Well, as the clubhead goes down the plane board, it's going way more laterally than vertically. That's why the shallower the VSP, the more the club path/true path/CP is way more to the right than the baseline (HSP) is pointing.
So shallow/small VSP's and high AoA's (postitive or negative) make the true path/CP a lot different than the the HSP.
When the clubhead bottoms out (zero AoA) the clubhead, for that brief moment, must be going the same direction as the bottom edge of the board (HSP), regardless of how much you tilt the plane board from the ground. I.E. at zero AoA, CP equals HSP, regardless of VSP.
Overall:
CP = HSP - AoA x [tan(90-VSP)]