I have a Q-Roll Firebird and as Q-Roll Classic IV, and both are excellent putters. What is most interesting is the putter face design, as it is radiused face that presents an impact point on the ball in the top quadrant and also presents a negative or delofted face to the ball (as it must since it contacts the ball in the top quadrant). And this is the case whether the blow is level, rising, or descending, but it will usually be level or rising. This combination promotes good rolling earlier than many other combinations.
These are Swing Dynamics testing results:
"Q-Roll submitted three of their putters to one of the leading independent testing firms, Swing Dynamics of Carlsbad, CA, for unconditional testing. The putters were set up on their robotic swing device in a standard position with the shaft at 90?. The putting surface was Swing Dynamic’s standard putting surface that produces a Stimp Meter reading of 10.7 with the length of the putts being 10 feet. According to Swing Dynamics, “We have never hit a 10 foot putt on a 10.7 Stimp Meter better than we did with this putter. It’s an industry first. Even on off-center heel and toe hits, Q-Roll’s putter held the putting line better and proportionally gave more true roll energy than any other putter we’ve tested to date.”
Averaged over a total of 10 center hit putts, the Q-Roll putter achieved a Putter Efficiency Index (PEI) of 0.96, with a total skid distance before achieving “True Roll” of 10.7 inches. On off-center toe hits the PEI was 0.99 with a skid distance to true roll of 10.5 inches, and on off-center heel hits, the PEI was 0.97 with a skid distance to true roll of 10.4 inches."
This is all consistent with my analysis of delivering a blow that transit thru the ball on a trajectory that passes above the ball's center of gravity, whether done with a lofted face on the ball's lower quadrant rising thru the ball or a negative loft on the ball's upper quadrant rising thru the ball (or even level).
The Q-Roll putter also has a nice total head weight, especially the Classic IV, which won the "Best of Show" award at the 2007 PGA Merchandise Show.
This sort of face design is probably a leader in putter technology going forward, as the old cant that putters need 3-4 degrees of positive loft is just not real in light of today's surface conditions. Robert bettinardi has been experimenting with zero, negative, and minimal face loft to good effect, and Norman Lindsay's putters have the face with the top half minimal loft and the bottom half negative loft as a backup in case the golfer makes contact on the face too low.
Cheers!
Geoff Mangum
Putting Coach and Theorist
PuttingZone.com
Golf's most advanced and comprehensive putting instruction.
Does the Q-roll putters have the same setup as the Lindsay putters (i.e. with the top half minimal loft and the bottom half negative loft as a backup in case the golfer makes contact on the face too low) ??
No, the Q-Roll has continuous radiusing, whereas the Lindsay face if top-half planar with minimal positive loft and the bottom-half is negative loft. The Q-Roll has a very mild radiusing, I believe something on the order of the outer curvature of a sphere with a diameter of 4 inches or something like that. Here is the patent abstract:
Abstract
A golf putter is optimized by providing a cylindrical ball-striking face with a radius of curvature of between about 2 and about 6 inches. The ball-striking face of the preferred putter is arcuate in cross-section and has a radius of curvature of essentially 4 inches about a horizontal axis lying in a plane parallel to and spaced essentially 0.84 inches from the sole of the putter. This shape for the putting face ensures that a ball will be stroked with a desirable over-spin. The putter also retains much of a conventional flat-faced putter's immunity to small variations that a golfer may make about an ideal stroking position.
Inventors: Garcia; Larry (Oldsmar, FL)
Assignee: Convex, Inc. (Oldsmar, FL)
Appl. No.: 07/933,784
Filed: August 24, 1992"
"Gradual loft reduction (face roll) can be used on the bottom of the putter-face to introduce a small amount of negative loft. This generates topspin by oblique impact, even though the ball is hit on the upswing on this part of the putter-face. This arrangement is especially beneficial for length control on long putts."
I believe this is the Lindsay patent for the bi-lofted putter face. This face design has a point 5 mm above the sole where loft changes from negative to positive, with positive above that becoming planar to 15 mm high, and below that the face radiuses in negative loft more negative the lower down the face to become planar at the end or bottom of the face.
Cheers!
Geoff Mangum
Putting Coach and Theorist
PuttingZone.com
Golf's most advanced and comprehensive putting instruction.
In terms of the research completed to optimize ball roll, is the objective to contact the ball above the sweet spot of the putter or to just contact above the equator of the ball or both?
Is there a clear winner on terms of design between the Lindsay or Q-Roll putters?
Assuming nothing about the height and recessing of the putter center of gravity with respect to the contact/impact point of the ball on the putter face (which relates to the vertical gear effect VGE), but addressing just a uniform rectanular 3D slab of metal (say, 1" high, 4" wide, and 1" deep) hitting a ball and how the angle of the impact plane meets the ball and how the center of gravity (COG) of the slab transits thru the sphere of the ball:
There are two ways to prromote forward roll --
1. angle of slab delofted (negative loft) to horizontal / equator plane of ball, making contact in top quadrant of ball, with center of slab rising and transiting above the ball's center of gravity;
2. angle of slab lofted (positive loft) to horizontal / equator plane of ball, making contact in lower quadrant of ball, with center of slab rising and transiting above the ball's center of gravity;
When you add in the vertical gear effect (VGE), which is "minimal" or even negative loft making contact on ball (wherever on ball) with the impact point on the putter face higher than the putter head's center of gravity and the center of gravity also recessed back from the face, this complements the above two dynamics.
Putting #1 together with the VGE is a little easier, mostly because #2 often results in the impact point on the face being lower than is generally true in #1. But that is not to say dynamic #2 does not often have the VGE. It is also not to say that #2 will not have the VGE to the same extent as #1. And, it is also not to say that #1 or #2 without VGE are not capable of generating as much forward roll as VGE in combination. These issues have not been studied.
In the case of contacting the ball below the equator, whatever "loft" angle is presented to the ball determines the "tangential plane" on the ball's surface where contact must occur. In other words, if the loft is 3 degrees at impact, the ONLY tangential plane where contact is possible is the one perpendicular to the radius line angled 3 degrees down from the equator plane, from the center of the ball to the lower qudrant of the surface. This also means that at the exact instant of contact, the putter face exerts a line of force directly at the ball's center. But, while contact between ball and putter persists, the trsajectory angle of the putter increases to directions higher than the bqall's center. The net result is that a "solid" upward blow is really a blow that transits above the ball's COG. This promotes forward roll.
My experience is that "hitting up" on a line of force above the ball's COG is more important than the face loft at impact, except you don't want to "launch" the ball off the ground with too much positive loft. My experience, agin, is that a normal putter with usual positive loft of about 3 degrees, playiong the ball about 1" ahead of the bottom of the stroke, impacted with a smooth tempo not far off gravity timing will not seriously launch the ball, but will give it a nice roll without much skidding.
I don't know if there is a clear winner between the two putters. I imagine the difference may not be clear enough to avoid getting swamped by variance in the golfer's technique.
Cheers!
Geoff Mangum
Putting Coach and Theorist
PuttingZone.com
Golf's most advanced and comprehensive putting instruction.
Thanks Geoff. Extremely informative and insightful as always.
Curious on your comment"Putting #1 together with the VGE is a little easier, mostly because #2 often results in the impact point on the face being lower than is generally true in #1"
What do you mean when you say a little easier (to perform)?
Are there negative implications to an lower impact point on the face?
Just to follow up on my last question in the previous post:
As long as the rise angle of the putter through the ball is at least 4 to 5 degrees are there negative implications to hitting the lower quadrant of the ball with a dynamically lofted putter?
The key dynamic that is not too troublesome in the case of lower-quadrant contact (which necessitates positive loft) is the movement of the putter head over the period of time from initial ball contact to separation of putter face surface and ball. In particular, at the initial moment of contact, the loft of the putter face is required by geometry to match the tangential plane on the surface of the ball at the point of contact. There is only one point of contact on the ball's surface where the loft of the putter face and the tangential plane are angled the same degree out of vertical, with the equator of the ball representing "0" angling out of vertical, and points lower than this being progressively more angled top-back or positive loft off vertical, and points on the ball higher than the equator requiring top-forward angling or negative loft on the putter.
So with loft at impact of 4-5 degrees, this means the point of initial contact on the ball must be lower than the equator. In particular, for 4 degrees of dynamic loft at impact, the point of impact on the ball is located by where the radius line from the ball's center points to the surface when the radius is angled down off the horizontal equator by 4 degrees. This point on the ball's lower quadrant is 0.059" below the ball's equator and 0.002" closer in to the vertical axis of the ball (line from bottom of ball thru center to top of ball).
This initial point of contact has the putter face force aimed and directed exactly at the center of the ball. But immediately thereafter, things change. The ball goes laterally left while the putter face continues to arc up with increasing dynamic loft. This period of changing dynamics is brief (on the order of 0.0005 - 0.0010 seconds). But if the loft increases 0.5 degrees while contact persists, then the point of contact "rolls" down the ball an additional 0.001" and also "slides" down the putter face an additional 0.002", while the ball shifts laterally left. Depending on how fast the putter head is moving at impact, the softness or hardness of the ball cover, and the mass of the putter head, the lateral movement of the ball will be something less than 1/10th of an inch during contact. This all means that the direction of the blow of the putter head thru the ball shifts during impact from a) right at the heart of the ball at the beginning, to b) progressively higher thru the top quadrant of the ball and above the ball's center thereafter.
Whether the ball "launches" much off the ground depends mostly on the angle at impact and the force of the blow in comparison to the inertial mass of the golf ball in gravity. This requires some testing, but my experience has been that a nice slow tempo does not launch the ball much at all off the ground.
So, all together, using a nice even tempo and dynamic lo9ft around 4-5 degrees at initial impact results in "knocking the top half of the ball over the bottom half of the ball" in a dynamic that promotes forward roll. This dynamic's key is that the force of the blow is directed ABOVE the ball's center. This dynamic is common to both rising blows of a delofted putter impacting the top quadrant and rising blows of a positively lofted putter impacting the lower quadrant.
Cheers!
Geoff Mangum
Putting Coach and Theorist
PuttingZone.com
Golf's most advanced and comprehensive putting instruction.
No. The putter face should be remaining square thru impact, not closing. The putter face may be rising and adding dynamic loft during impact, but not closing.
The lateral left motion of the ball ("left" = targetward, for right-handers) begins at the start of impact. At the first, there is a little compression of the ball's cover material. This compression creates a small "footprint" on the cover roughly on the order of the size of a single dimple. Once this compression is well under way, the ball starts to move targetward on a velocity vector (direction and speed) in 3D space. This vector need not be "horizontal" to the surface, but may be angled up or down depending upon "launch conditions" of the dynamics of impact. But the vector should not be angled left or right of the line defined by the direction the square putter face aim and moves.
The "vector" (speed and direction) of the putter head during impact determines the line the ball rolls on and its speed (the ball "vector"). If the putter head "vector" changes direction while impact is occuring, as happens if the putter face is "closing" while impact occurs, then the ball "vector" will not be the same as when the putter face stays square and moves straight (no "closing" or "opening" while impact occurs). Instead, the ball's vector will be a "result" of all the changing directions of the putter head from the start of contact until the end of contact, sort of an "average" direction and speed. In other words, if a right-hander's putter face is "closing" while impact is still going on, his ball will not roll the same direction as the putter face aimed at the very beginning of impact, but will roll in a direction slightly to the inside of this line, but not as angled inside as the very last "closed" angle of the putter face when contact ceases.
Cheers!
Geoff Mangum
Putting Coach and Theorist
PuttingZone.com
Golf's most advanced and comprehensive putting instruction.