Visit to Ping headquarters

Factory tour

• At about 4:20 of the first video, Karsten points out that, for an iron, heel-toe weighting is not all you should do to "enlarge the sweet spot"; it is also worth doing top-bottom weighting as well. A high or low miss would then be forgiven, just as heel-toe weight forgives a miss toward the heel or toe. The chalk dots Karsten places on the board tells me exactly how he came up with that unusual design for the Ping Zing clubhead. It was a way to get extreme weighting high on the toe.
• At about 5:20 of the first video, Karsten does a demonstration of shaft flex that I believe to be seriously flawed. But it does clear up a point of curiosity for me. While Karsten himself was in charge of the company (his son John Solheim runs it today), their irons always carried very stiff shafts. True, they pioneered custom fitting, as far as a big OEM clubmaker as concerned. They were the first OEM -- by a lot -- to recognize that golfers needed different lie angles (as well as lengths and swingweights). But they only had one flex of shaft, and that was super-stiff. There have been many misconceptions over the years of the role shaft flex plays in a golf club, and I view this as yet another misconception. Today, they fit for flex as well as the other important fitting parameters.
  
  So what is the flaw in Karsten's reasoning? In the demonstration, he uses nearly the same tip deflection for very soft, medium, and very stiff. The problem is that, for a given load (a given golfer's swing), the deflection decreases as the shaft gets stiffer. So, to make the demonstration reflect reality, he would have to use proportionately less deflection for a stiffer shaft. At that point, it is likely that a stiffer shaft would not show an improved "fling" of the ball. In fact, research by TrueTemper in the early 1990s showed that shaft stiffness and the resulting kick velocity have little or no effect on ball speed. So what the stiff-shafted Eye-2 irons did was provide a stiff feel (good for some, not for others) and a smaller shaft bend (different clubhead position at impact) -- not more clubhead or ball speed. (Actually, the demo itself may not be a valid metaphor for what a clubhead does in a golf swing. But, even if it is, I have explained the reason it does not justify a super-stiff shaft.)
  

• Every iron the factory turns out is made to a ticket order. Most are in fact custom orders. Others are orders from off-the-rack retailers, reflecting their specific inventory needs. They are all made to specifications on an order ticket that travels through the assembly line with the components as the "kit" for a set of irons. This is very different from what I saw at Callaway and TaylorMade 15 years ago; they had assembly lines that made the same club over and over -- then switched to a different club when they had enough.
  
• There are a number of lines (Ping calls them "cells") for making irons. (Don't remember whether it is 8 or 10 cells, but that is about the right number.) A kit travels over one of those assembly lines as a unit. The workers are all cross-trained in all facets of iron assembly. They typically work a half-day at one station (say, gluing heads to shafts), break for lunch, and spend the rest of the day at another station (say, bending loft and lie). I think that is great for employer-employee relations; it prevents getting bored (or getting repetitive-movement injuries) from doing the same job over and over. And Ping's record confirms this; they have a surprisingly large number of 20- and 30-year employees, both in the factory and the engineering group.
• The loft-lie station was of special interest to me, having tried to bend older Ping irons. Several points here:
• Orders for Ping clubs include lie angle by color dot. That is, a "black dot" is normal or standard lie, a "red dot" is 0.75º flat, a "blue dot" is 0.75º upright, and so on for twelve dot colors and a range of almost ±4º. The clubheads are cast to nominal loft and black dot lie, and are bent to the proper lie (indicated by the order ticket) after the clubs have been mostly assembled.
  
• They have to adjust both loft and lie, even though the clubheads are nominally made to the eventual loft. If you have ever bent a club to spec, you know that, try as you might, you are likely to change the loft while you bend the lie or vice versa. A skilled clubmaker may be able to minimize the number of bend-measure-bend iterations, but you still have to measure both every time.
• The bending itself is done by hand, but Ping has an impressive machine to measure loft and lie in the bending vise. The machine takes the order ticket spec, and matches the club to that spec. The display shows two colored blobs on a computer monitor; the spec is green and the actual club red. The horizontal axis is lie and the vertical is loft. Looking at the relative positions of the circular blobs, the worker can see what direction to bend, and by how much. That information minimizes the iterations, and being driven by the ticket specs precludes errors in the order.
• Ping makes their iron heads out of 17-4 stainless steel. They claim that is "the best". I do know that it is the hardest, the most durable, and the least bendable, of golf-iron steels. Having tried to bend a few myself, I am most impressed with the effectiveness of the process they use. Is 17-4 the best? It probably is for the business model of Ping clubs. It might not be in general. Consider:
• Every set of Ping irons is custom ordered to specification -- and presumably custom fit for the order. They have the factory set up with the equipment to bend 17-4, including a special heat treatment. Having been bent to spec, it will stay that way because it's 17-4. Hence Ping's assertion that it is the best.
  
• If an independent fitter needs to bend the clubs after manufacture -- for instance, if you take lessons and your swing changes a bit -- the composition of the steel will make bending rather difficult. This also makes selling/buying used Ping irons somewhat chancy, because they are not amenable to adjustment for the new owner. And 17-4 is certainly not the best for clubs that were just bought off the rack rather than fit from the beginning. You want off-the-rack clubs to be at least as bendable as 431 stainless, so they can be properly fit after the fact.
  
• Finally, most of Ping's iron models are game improvement designs. But it is an article of faith that "player's clubs" should be forged steel, because the softer steel gives a better feel. (I would take issue with this, but it's an attitude that can't be fought in the marketplace.) In fact, Ping's "player's club" (the Anser) is not 17-4 stainless but rather the more ductile 8620 steel.
  
• Swingweighting is done by adding weights in the cavity backs. (Picture at right.) The weights are manufactured by a molding machine in the same building. They are a composite of tungsten (for mass) and elastomers (for adhesion and vibration damping). They are epoxied to the heads by hand, to the order of a digital swingweight scale that has been programmed with the order ticket for the set. The worker has bins of sorted weights, and chooses the one the swingweight scales says to.
• Swingweighting metalwoods is another story. I had mentioned the process I saw at Callaway 15 years ago for swingweighting metalwoods; it used epoxy injected into a hole in the metalwood shell, under control of an automated swingweight scale. Jack said Ping uses a material he called "Gi-Loo" to add weight, and also to add some stickyness to the inside of the shell so any floating chunks of epoxy or metal would stick to it rather than rattle. This sort of material has been around the industry since the advent of metalwoods. Most clubmakers I know call it "mouse glue" because its stickyness is similar to the glue used in commercial mouse traps. It is used on the inside of almost all metalwoods to prevent rattle. But I have seen it used -- and often used it myself -- to add head weight to a metalwood. So the application is not novel, though probably unusual for an OEM factory.
• Finally, a word about putter shafts. We did visit the putter factory on the tour. Realize that Ping's business started with putters, and the company even got its name from their first putter. Their big photo-op at the facility is the Gold Putter Vault (more on that later). So of course they would include the putter factory on the tour.
  
  Many models of putter require a shaft with one, two, or even three bends in it. The most common is two bends: one for lie angle and one for offset. How a two-bend putter works is shown at the right.
  
  When I build a putter requiring a double-bend shaft (including my current favorite putter), I have to buy a pre-bent shaft. I have to go through catalogs until I find one with the correct bends. Then I have to play with tip length until the bend is exactly right with respect to the center of gravity of the clubhead; otherwise the putter will not be face-balanced.
  
  Ping does it the right way. They have an absolute artist at shaft bending, and he has the proper tool to bend a steel golf shaft. (I don't know how he does it without cracking the chrome plating; must be a pretty special shaft to begin with.) The club arrives at his station with the shaft already epoxied to the head. He bends the shaft itself to lie and offset -- per the order ticket, as usual around here. During the bending, he also continually checks face balance; when the putter leaves his hands, it is perfectly balanced. I was very impressed. I asked, and Jack admitted that this guy was seldom assigned to anything but bending putter shafts.

Engineering tour

PingMan

• The "wrist joint", where the arm holds the club's grip, is completely unpowered. It just hinges freely, with a stop at the maximum wrist cock angle. This is what the best golf swings do, though almost everybody I play with tries to use the hands and wrists to add power. If you want to see why a free-hinging wrist is the right way, read almost any of the articles on my "Swing" page.
• The maximum wrist cock angle is well beyond 90º. Calvin tells me that is because the robot is designed for clubhead speeds up to 150mph. Trying to attain that speed with a wrist cock of only 90º would place too much strain on a graphite shaft less than XX flex; it would probably shatter. This is consistent with the long drive competitors, the only golfers who can even approach a 150mph clubhead speed. (They are typically in the 130s.) For instance, look at any video of Jamie Sadlowsky's swing; you'll see a huge wrist cock, which he holds almost to impact. This is the sort of swing that PingMan imitates.

• Staying with the wrist joint, it is geared to rotate the club's shaft about its axis. The club rotates through 180º in a normal good swing, from the face in-plane at the top of the backswing, to the face square to the target at impact (90º so far) to the face again in-plane the other way at the end of the follow-through (the other 90º). To properly test a club, the robot must mimic the human in the rotation of the club. In a proper golf swing, this rotation tracks the uncocking of the wrists reasonably well, so Ping just geared the rotation to the uncocking of the free-hinging wrist joint.
• The PingMan robot has an offset "shoulder". That is, the arm does not extend from the center of rotation, but rather from the edge of the shoulder "plane". This is claimed to add a level of realism other robots don't achieve. I will agree if the shoulder joint moves with respect to the driving shoulder disc during the downswing. If not, then the actual performance is the same as a rigid arm from the center of rotation.
• Now we get to one of my favorite features: the tee. I'm sure you noticed that the tee retracted before the swing, acquired a golf ball, and returned to the address position. I'm sure you were thinking, "I'd like a caddy to do that for me at the driving range." But that isn't the reason it's my favorite feature.
  
  Ten years ago, I put together a test to be run at the GolfLab robot facility in San Diego. One of the problems in conducting a robot test is controlling where on the clubface impact occurs. At GolfLabs, impact was controlled by resetting the grip of the club in robot's "hand". When you do that, you change face angle, lie angle, and length simultaneously; you can't change one independently of the others.
  
  With PingMan, it is much easier to deal with. The tee is positioned by a servo drive. To change impact position, you simply program the servos to place the tee in a different position; you never have to ungrip-regrip the club in the robot's hand. Set it up; hit one ball; measure where on the face it was hit. Now you're ready to program the servos for any impact position you want.

Other Range Instrumentation

Club and Swing Measurement

Putters

• The things that iPing measures, like loft at impact and arc of the stroke, are part of the DNA of the golfer's putting stroke (Paul's term, but I like it). It does not change much at all when the balance point changes. So most of the putter fitting can be done using iPing. But...
• The correct heft and balance for the putter needs to be separately fit without the iPing, after the iPing fitting determines the other putter specs.