Impact Information from "unnamed source" who worked at Taylor Made in the 90's

[Todd Dugan]

I understand gear effect and all ball flight laws. Forget i posted my response. It was largely responding to whether the face is closing thru impact or not.

I know that you guys know this stuf inside-out, Kev.

But now I'm wondering..... if you hit a driver on the toe and the ball hooks, would TrackMan indicate that the clubface is closed to the Path even though the Clubface will have twisted well open to the Path by Max Compression?

 

[Kevin Shields]

It would indicate spin axis negative, face open to path. people are sometimes amazed how quickly i know they hit it on the toe without even looking at the swing

 

[Todd Dugan]

It would be interesting to know how it makes that calculation since the machine doesn't actually measure or "see" the horizontal clubface angle during impact. I suppose when the ball starts right of the horizontal clubhead path AND spin axis is negative, then the machine KNOWS that it is a toe impact and adjusts accordingly. Because for a center impact, the ball would have to start left of the path if spin axis is negative.

 

[SteveT]

That's cool. I'm just trying to contribute some interesting and relevant content here. So you're saying that the clubface rotates hardly any during impact? What about the couple feet leading up to impact? Any research numbers available there yet, Brian?

Your lead (left) hand is supinating about 90º from top of swing to Impact, and the clubface will follow .. plus or minus the effect of downswing shaft flex loading. In the last couple of feet of the downswing the amount of rotation is dependent on which kind of shaft loading profile you create in your swing. Hope that helps.