[Mike O]

[quote=Millrat]

Check this out... Swivel? Notice the little pins..one is fixed at the shoulder at in ...the other is rotating...?????




This sketch is confusing (to me anyhow). 2K-4 shows a left arm in a plank type of representation with the club in the same rectangle shape. In 2K-5 the club has rolled up to vertical however the left are appears not to have changed (swiveled) it just shows the wrist hinge pin in different place with the rectangle intact. Is this a poor sketch or am I missing something.

If a sketch were made of the in-between picture, could the club and left arm (below swivel) be shown rolled up to 45 to 2K-4? Would a clockwise circular arrow make it a bit more clear?

CW

CW,
Something not clear in the Golfing Machine- Either that's Blasphemy or a Revelation

Seriously, you bring up some good points for clarification. Yes, I agree a number of things could be done to make this sketch more clear.

For one, the left arm should be represented with the sides and top as the same width- that way, when the swivel takes place at the forearm/elbow- it wouldn't appear (as you note) that just the hinge pin was moved- although certainly by analyzing the club movement in the sketch you should be able to determine the essence of the sketch.

It would also be nice if the before swivel (2-K-4)and the after swivel (2-K-5) clubshaft locations were not so close to the same location. With that amount of #3 accumulator i.e. the divergence between the arm and the clubshaft- the swivel motion is going to create the clubhead or the end of that stick in this sketch to move through a pretty good length of arc- which doesn't show up in the sketch.

Also, the 2-K-5 sketch should show both the arm and the clubshaft pointing in the same direction- not different directions.

Also, 2-K-4 would be better labeled "A left arm plane- on-plane wrist motion". In 2-K-4- the "Left Arm" indicating arrow should identify both sections of that board- the portion below the "swivel" as the forearm and the portion above the "swivel" as the upper arm/humerus. Otherwise, one might look at the upper portion of the board as the left shoulder and the lower portion of the board as the entire left arm - thereby incorrecty inferring that the "swivel" happens at the left shoulder.

There may be a lot more good ideas/improvements to this sketch- as you mention an arrow denoting rotation etc.-

Now, in case it's not perfectly clear- let's make sure that Mathew knows this is the blueprint of a new and improved sketch that we're looking for, and CW is overseeing the entire production and revision process for the 8th edition- for input please call him at home- although due to his busy schedule he only wants phone calls between 12 midnight and 5AM in the morning.

I'm strictly a 6th edition machiner- so upon just looking at the 7th edition- the left wrist hinge pin has been removed from the sketch- either on purpose or by error of ommission - either way it's not there- although the label for the left wrist hinge pin is there.