Clubshaft orbit through the impact zone

[O.B.Left]

Luke

Lensing issues aside where is it best to position a camera for a down the line swing? On the base line, opposite the hands or?

Thanks
OB

[chbkk]

Jeff, you said "The issue of the clubhead swivelling into impact is a separate issue. I actually think that it happens automatically. Have you watched an Iron Byron machine in action? It has a universal joint that is totally passive. The clubhead swivels automatically to allow the clubface to become square at impact. There is no device in that macahine that actively causes the clubface to become square at impact. "

For Iron Byron, I have tried to find more information through google without success. I would love to hear how the clubhead can do a 180 degree swivel unpowered (i.e. only by inertial forces). I can learn something here. Thanks in advance.

[Toolish]

I thought Iron byron had stiff 'wrists' and Pingman had the more flexible joint there?

[YodasLuke]

Luke

Lensing issues aside where is it best to position a camera for a down the line swing? On the base line, opposite the hands or?

Thanks
OB

One way you can do it is to take a laser pointer and place it on top of the camera. Shoot it at the player's hands to get the first estimation of height and location. Since almost no one swings on a Hands Plane, I move the camera toward the ball about two to four inches. I find that almost all of my players' strokes fall between the Elbow and Turned Shoulder Planes. So, my goal is to get the camera's eye looking straight down Plane.

I've heard some suggest that the camera should be placed at shoulder height. Those that use this height suggest that it comes closer to the teacher's eye level view. It's my opinion that it's less important what the club is doing at Top or End. I feel it's more important to see what the club is doing from Release through Impact.

I have also heard suggestions that the camera should be placed on the base line. The only way this would be possible would be to have the camera's eye looking through the back of the ball. I've never seen it done this way.

Another way would be to have the camera follow the club up and down the Plane. I have no idea what this would cost, as you'd have to have some way to match the Acceleration Rate of each player.

You'll notice that many of the videos that we see, as in Kim's video, are taken by a cameraman that has the camera on his shoulder. Additionally, he's standing off Plane. This is fine for TV, but it's not good for analysis.

As you've seen in some of the 3-D pics that I've placed on this site, you can place the camera's eye in many places. This technology is obviously the future. But, I'm going to wait until it's less than $250,000. For now, I'll have to remain in the Dark Ages, using video.

[O.B.Left]

Thanks Luke

I have never thought of moving it off the elbow plane to adjust to the players chosen backswing plane or downswing plane. Makes perfect sense.

Sorry for thread jacking but while we are talking planes:

The Butch Harmon laser trainers have one light pointing out the grip end and another one pointing from approximately the #3 to the sweet spot (coincidence rather than TGM compliance probably). With constant back and forth swinging you can get the two ends to trace a straightish line from horizon to horizon along the target line , albeit with some wobbling as the sweet spot laser rotates off the inclined plane to the sweet spot plane.

Do you know of another or maybe better way of practicing plane compliance? If so please share it. I have the Harmon lasers and find them to be very helpful although my neighbours must be wondering what the heck is going on in the dark of my living room. They can shine out the windows and on to trees etc.

OB

[mb6606]

Thanks Luke

Do you know of another or maybe better way of practicing plane compliance? If so please share it. I have the Harmon lasers and find them to be very helpful although my neighbours must be wondering what the heck is going on in the dark of my living room. They can shine out the windows and on to trees etc.

OB

IMHO the best method that cannot be cheated is to stand inside Mr Kelley's full length plastic plane.

[Jeff]

Toolish

I should have stated Iron Byron-type machines.

I have never seen the original Iron Byron machine. I have only seen one version of that type of club-testing machine at our local golf practice facility. It is a very advanced machine, which they call Robo-Fit. It has an universal joint that allows the clubshaft to rotate about its axis.

chbkk

I don't have a conclusive answer as to how the clubhead swivels automatically in an Iron Byron-type machine that has an universal joint. I have previously thought that it relates to the COG of the clubhead's mass relative to the hosel, and I have presumed that the offset COG of the clubhead causes the clubhead to swivel around the clubshaft's axis. If you establish a conclusive explanation, please let us know.

Here is a link to the company that makes the machine.

http://www.golflabs.com/home.html

Here is a link to a comment about the wrist joint

http://www.golflabs.com/robot_sales_2.html

I wonder if nmgolfer can work this problem out mathematically.

Jeff

[YodasLuke]

chbkk

I have previously thought that it relates to the COG of the clubhead's mass relative to the hosel, and I have presumed that the offset COG of the clubhead causes the clubhead to swivel around the clubshaft's axis.

I'm aware that I'm beating the dead horse into glue. But, there's a concept that must be understood. My goal is to clearly state an idea, not to beat you (Jeff) or your ideas into the ground. I wasn't born with these ideas. Thanks to Homer and Lynn, I have a much better understanding.

The Clubshaft is not the axis of rotation. It is the club's COG that is the axis of rotation. It's a stumbling block that is supported by the use of a Plane board.

Many times, I've used the example of a lathe. A baseball bat is symmetrical, and it's made on a lathe. When the bat is finished, it can be spun at any speed (RPM's) and it doesn't wobble. A golf club is not symmetrical. If you place the golf club on the lathe and use the shaft as its axis of rotation, you need to seek cover when it's spun at high speed. On the other hand, if you use the club's COG (a line from the #3 Pressure Point to the Sweet Spot) as the axis of rotation, you can stand and watch. There's no danger of the club flying off the lathe.

Using the Clubshaft as the axis or rotation is not logical. If we assume that your argument above is true, you would assume the force that would quickly swivel the Clubhead around the Clubshaft would be a divergent force vector. The resulting wobble would pull the Clubshaft off of the Plane Line that you were attempting to trace. It results in scattered force vectors, and a less than perfect application for compression. It is the club's COG that must trace a straight Plane Line, not the Clubshaft.

Are we even remotely in agreement?

[chbkk]

Jeff.
Thanks for the links. Not universal joint though. It looks like synchronized shaft rotation with uncocking action through gears. Wish I could have similar arrangement on my wrists.

[Jeff]

Yodas Luke

I can understand the concept of using PP#3 to aim the sweetspot of the clubhead at the base of the inclined plane as one traces a SPL.

However, I have a hard time understanding how the hosel rotates around the sweetspot-to-grip axis - especially with respect to the Robot-Fit golf club testing machine. I would like to read your explanation of how the clubface passively rotates to square by impact in that machine.

Jeff.