Variable Torque Control User Guide

Congratulations on your Kelly & Co Blade Z DB putter. It features Variable Torque Control -- VTC -- the ability to adjust the torque and balance to give you the best possible putting results. That means you need to know how to do the adjusting. Here is your User Guide for VTC.

1) Choose the right neck

You should have some idea of what kind of balance regime you want for your putter. Zero torque? Face balanced? Toe hang? Each one is best served by a neck for the Blade Z putter. Select an appropriate neck for your intended balance regime.

Balance regime	Rest position	Blade Z DB setup	What that balance does
Zero torque	Any position, but with negligible torque holding it there.	(short neck) (long neck)	The putter face responds to exactly the torque you apply with the hands. If you have a steady grip with no twist, the head will not pull the face out of square. If your hands apply any torque to the shaft, the face will respond. The head will not help to keep the face square.
Face balanced		(plumbers neck)	Your hands must apply a steady torque to keep the face square. That torque is exactly the same torque as what you needed to square the face at address. Just keep that through the stroke and the face will stay square. If during the through swing, your hands apply more or less torque than at address, the clubhead will apply a self-correcting torque to keep the face square to the path of acceleration.
Toe hang - angled		(plumbers neck or slant neck, only for heel-shafted Blade Z DB HS)	Probably the most common putter balance in use today and in recent decades. It includes putters like the Anser and Newport. Requires torque at address to square the face. Requires varying torque to get the face to square at impact. This might be for you if you learned golf with a toe hang putter and don't intend to learn a different putting stroke. If you are happy with your putting results with this type of balance, then you can stick with it.
Toe hang - straight		(short neck or long neck, only for heel-shafted Blade Z DB HS)	Lots of older putters like this; the best known is the 8802. Think of this as the angled toe hang putter on steroids. Everything about it is the toe hang, but to the extreme.

2) Set up the right weight for your putter

Let's assume you have a favorite way to find the right weight for your putter. Or maybe you're going to find it for this putter. The latter is the way to go if you are setting it up for zero torque, because zero torque putters feel lighter than other putters -- by about 20 grams, according to people who have looked at it. So perhaps you ought to set a weight, try it out, and add or remove weight until it feels and performs best.

But how do I add or or remove weight? There are 6 or 8 weights in a BladeZ DB putter, that fit into 6 weight ports in the body. Which weights do I change and in what order?

Here's the terminology we will use to talk about weight ports.

• There are three ports at the toe and three at the heel. The ones at the toe are designated T and the ones at the heel H.
• The ports are numbered from the face to the back, 1, 2, and 3 respectively.
• Examples: The port nearest the face on the toe end of the putter is called the T1 port. The middle port on the heel end is called the H2 port.

The 1 ports, nearest the face, are double depth. They can accept one long weight or two short weights. The 2 and 3 ports each accept one short weight.

Your BladeZ DB putter was initially set up with all weights steel, which puts its weight (clubhead plus short neck) in the middle 390s (in grams). In order to lighten the club, some of the weights must be changed to aluminum. In order to make it heavier, some of the weights must be changed to tungsten.

There is a table of how to get the putter head to a particular weight. (The table is for the Blade Z DB head and neck, with no shaft. That makes it comparable to head weights for other putters, which do not have interchangeable necks. The neck for the table is the short zero-torque neck; other necks will be slightly heavier.)

Where AL=aluminum and SS= stainless steel
When tungsten weights are available, the table will be expanded.

At this point, you are as close as you can get to the weight you want.
But...

The minimum recommended weight, with nothing but aluminum weights in the ports, is about 260 grams. If you need it lighter than that, some empty weight ports might do the trick. But remember to use LocTite Blue on the screw caps for those weight ports, so you don't lose the caps in play.

3) If you intend a zero torque balance regime, get the lowest possible torque

This step only applies if you have a neck suitable for zero torque, or at least very low torque, and only if that is your balance goal.

Let me emphasize that point! If, for instance, you want a face balanced putter but you only have a zero torque neck for your Blade Z DB putter, you need a different neck. Yes, it is possible you can move the weights around so it will balance with the face up. But the torque keeping it face up will be so small that the result will have none of the desirable characteristics of a face balanced putter.

Conversely, our adjustment for lowest possible torque does not care what the rest position of the putter is. Face up? Heel down? Something else? It won't matter a bit in performance nor feel. It will behave as zero torque, independent of the rest position.

Having gotten that out of the way, let's see how we "zero out" the torque.

We measure how much torque there can be by placing the putter shaft on a flat surface, like the corner of a table. But we are not trying for a particular rest position of the club. Instead, we want to time how fast the club rocks back and forth. The slower it rocks -- or "oscillates" -- the lower the potential torque. The final rest position only matters in that it will tell us where the next weight change needs to be. Here is a video of how we time five oscillations.

We have computed a table for how the oscillation speed relates to zero torque performance of the Blade Z DB putter. A rule of thumb is:

The Revealer is an instrument invented by L.A.B. putters to demonstrate how its putters have very low torque. The example in the video shows a deliberately unbalanced Blade Z for purposes of illustration. The typical Blade Z DB putter with its initial weight configuration times out at 11 seconds or more. Tuning the weights with the following procedure often results in more than 15 seconds, an extremely low torque.

(Note that other putters might give a slightly different speed for the same performance. It probably won't be a large difference. )

The tuning procedure goes like this:

1. Balance the putter flat on its shaft, and see what the rest position is. Heel down? 45� toe down?
   
2. Find the picture that best matches the rest position in the table below. Make the weight change suggested in the table for that rest position.
• The action bullet points are listed in order. If you can't complete the first one (for instance, it says "Make H2 lighter," and H2 already has an aluminum weight so it can't get lighter), go on to the next one.
  
• If you can't make any of the changes suggested, then you probably can't do any better. You are done.
  
3. Time the oscillations as shown in the video. The more time it takes, the lower torque the putter is.
   
• If the time is high enough for you to be satisfied, you are done.
• If it the time is longer and you want to get it better still, go back to step #1 and repeat.
• If the time is lower than your previous try, then you probably can't do any better. You are done.

Rest position	Action
	Change T3 or H3 to a lighter weight, and split T1 and H1 to make each half-lighter. Change T2 or H2 to a lighter weight, and split T1 and H1 to make each half-lighter.
	Change H3 to a lighter weight and T2 to a heavier weight. If you can't make H3 lighter, then make H2 lighter. If you can't make T2 heavier, then make T3 heavier. Change H1 to a lighter weight and T1 to a heavier weight. If this results in a shorter measured time, then back off and do it with a split H1 and T1.
	Change H1 to a lighter weight and T1 to a heavier weight. If you can change H1 but not T1, change T2 and T3 to heavier weights. If you can change T1 but not H1, change H2 and H3 to lighter weights. Change H2 to a lighter weight and T2 to a heavier weight. Change H3 to a lighter weight and T3 to a heavier weight.
	Change T3 and T2 to heavier weights, and H1 to a lighter weight. Change H3 and H2 to heavier weights, and T1 to a lighter weight. Change T3 and T2 to heavier weights, and H3 and H2 to lighter weights. Change T1 to a heavier weight and H1 to a lighter weight.
	Change H3, T3, H2, and T2 to heavier weights, and H1 and T1 to lighter weights. Change H3 and T3 to heavier weights, and split H1 and T1 each to light+heavy. Change H2 and T2 to heavier weights, and split H1 and T1 each to light+heavy. (Be surprising if this did much at all.)
	Change H3 and H2 to heavier weights, and T1 to a lighter weight. Change T3 and T2 to heavier weights, and H1 to a lighter weight. Change H3 and H2 to heavier weights, and T3 and T2 to lighter weights. Change H1 to a heavier weight and T1 to a lighter weight.
	Change T1 to a lighter weight and H1 to a heavier weight. If you can change T1 but not H1, change H2 and H3 to heavier weights. If you can change H1 but not T1, change T2 and TH3 to lighter weights. Change T2 to a lighter weight and H2 to a heavier weight. Change T3 to a lighter weight and H3 to a heavier weight.
	Change T3 to a lighter weight and H2 to a heavier weight. If you can't make T3 lighter, then make T2 lighter. If you can't make H2 heavier, then make H3 heavier. Change T1 to a lighter weight and H1 to a heavier weight. If this results in a shorter measured time, then back off and do it with a split T1 and H1.

Notes:

1. The table was designed to keep the same weight as you adjusted in Part 2 of this User Guide. Suppose a really low torque is more important to you than the exact weight. If so, you can continue the procedure, but where it says "and" in the Action column, just do one or the other, not both. You might be able to get even a bit lower torque than before.
2. If you split the long weight in T1 or H1 into two shorter weights, the heavier of the two should be the more outside weight.
   
3. The pictures are of a right-handed putter. If you have a left-handed Blade Z, then pay attention to the heel-toe nature of the slant, not whether the slant is to the right or the left.
   

4) Tuning for your stroke

Now you have your Blade Z DB putter at a proper weight and balance. But your stroke may have a left-right tendency, which will cause the face to be slightly open or closed at impact. If putting on a flat surface shows such a tendency, it might need some balance adjustment. Before you do anything to the balance, though, make sure that a hand torque tendency is the culprit. Here are some things equally likely to be at fault:

• Visual: your putter aim is biased.
• Grip: your hands are not properly aligned on the grip, or the grip is not properly aligned on the shaft.
• Other possibilities, like stance alignment.

If the left or right bias is a torque tendency, then moving even a small amount of weight between heel and toe can fix the problem. Note: if you have a zero torque putter, such an adjustment may make the the torque slightly higher (faster oscillation, shorter time measured). But that is OK. A perfect zero torque is not for you. Your hands are applying some torque to the grip, and you need to rebalance to counter that torque!

Here's how to go about it.

Appendix - Frequency as a measure of torque potential

This will not be a complete derivation; I am preparing a technical article to cover that. But I do want to suggest where I get oscillation frequency as a measure for the torque potential of a putter head.

Let's start with some basic physics we should all know:

Mash them together, and we get

We are looking for the potential for an acceleration to produce a torque. The equation says the torque will be proportional to the acceleration. So we could express the torque potential (call it P) as the torque without the acceleration in the formula:

The clubhead rocking back and forth (oscillating) is a rigid pendulum, whose frequency is given by a well-known formula. When we plug that formula into our expression for P and do a bunch of pretty simple algebra, we get:

The final factor (in parentheses) is a constant, so the torque potential is just proportional to the frequency of oscillation squared and the moment of inertia. Moving the weights around in a Blade Z DB putter does not change the moment of inertia much; also the the frequency is squared, which boosts its importance. So we can consider torque potential as frequency squared without much error. As we slow down the frequency, we are minimizing the torque potential -- the ability to create torque when we accelerate the clubhead or expose it to gravity.

Finally, frequency is the number of cycles divided by the time it takes for that number of cycles.

So what frequency is low enough to be considered "zero torque" for practical purposes. That is, low enough torque that it affects neither feel nor performance? L.A.B. golf claims that its "Revealer" instrument distinguishes between torque that is low enough and torque that will affect the putt. I tried a lot of configurations of the Blade Z DB (as well as a number of other putters with known balance regimes). Each putter and configuration was tested for frquency, and for its performance in the Revealer. That gave a very good idea what frequency is the breakover between passing the Revealer test and... well... being a little dicey. Maybe quivering or wobbling. Turns out that number is about 0.55 cycles per second, or 9.1 seconds to make 5 oscillations back and forth. Rounding that up to 10 seconds gives us (a) a safety margin and (b) a nice round number, easy to remember.