changing length of LAB lie balanced putter

[ShawLF]

I know this topic has been discussed in the past with some stating that a LAB putter can be shortened by 1-2" without causing the putter to become unbalanced; however, this has never made sense to me since changing the length of the cylinder rotating around its lengthwise axis has no impact on axial torque or MOI. The only way I can see length having an impact on rotational torque would be if it caused the player to swing the club on a different lie angle.

 

Does anyone have a plausible explanation to support how changing the length causes the putter to become unbalanced?

[Howard_Jones]

1 minute ago, ShawLF said:

I know this topic has been discussed in the past with some stating that a LAB putter can be shortened by 1-2" without causing the putter to become unbalanced; however, this has never made sense to me since changing the length of the cylinder rotating around its lengthwise axis has no impact on axial torque or MOI. The only way I can see length having an impact on rotational torque would be if it caused the player to swing the club on a different lie angle.

 

Does anyone have a plausible explanation to support how changing the length causes the putter to become unbalanced?

Simply look at Scotty Cameron and what head weight thats "standard" vs play length

35" = 330 grams
34" = 340 grams
33" = 350 grams

Balance will change, when we go longer or shorter, the question is if its for the better or worse for YOU?
 

[ShawLF]

@Howard_Jones thanks for the reply Howard. I understand your point about balance which is valid; however, I'm trying to understand the effect on "lie angle balance" where the club doesn't exert any radial/twisting torque.

 

For example, consider a sphere attached to a rigid rod. If you were to swing this like a pendulum it would not exert any twisting force which is what LAB calls being lie angle balanced. Conversely, a putter, especially with toe hang, will exert an axial torque that will open/close the face during the putting stroke.

 

In the case of the object that is lie angle balanced, changing the length of the shaft has no impact on MOI, so torque is unchanged.

[ShawLF]

This is a good demonstration of lie angle balanced. I can't see how the length of the shaft plays a role here.

 

 

[Howard_Jones]

2 minutes ago, ShawLF said:

@Howard_Jones thanks for the reply Howard. I understand your point about balance which is valid; however, I'm trying to understand the effect on "lie angle balance" where the club doesn't exert any radial/twisting torque.

 

For example, consider a sphere attached to a rigid rod. If you were to swing this like a pendulum it would not exert any twisting force which is what LAB calls being lie angle balanced. Conversely, a putter, especially with toe hang, will exert an axial torque that will open/close the face during the putting stroke.

 

In the case of the object that is lie angle balanced, changing the length of the shaft has no impact on MOI, so torque is unchanged.

Just like a longer shaft needs a lower head wgt and a shorter shaft needs more head weight to deliver the same resistance, the same happens with lie angle, since we move COG when we change lie angle

Going flat, boost distance from the grip end to COG
Going upright, reduce distance from the grip to COG

So its the same as going longer or shorter, only in smaller scale...

For irons, 4* as change of lie angle is 1 SWP (average 2 grams), so its not much compared to a length change

I have never heard about "lie angle balanced", so i have no clue about what they are talking about

[Howard_Jones]

5 minutes ago, ShawLF said:

This is a good demonstration of lie angle balanced. I can't see how the length of the shaft plays a role here.

 

 

LOL...

NO,  play length will not change that if that was the question, but feel of head weight and balance of the putter will, for the better or worse, all depending on whats right for you.

[ShawLF]

2 minutes ago, Howard_Jones said:

Just like a longer shaft needs a lower head wgt and a shorter shaft needs more head weight to deliver the same resistance, the same happens with lie angle, since we move COG when we change lie angle

I 100% agree with this. In the case of a lie angle balanced putter, the COG must be along the axis of the shaft at a specific lie angle (the sphere on a rod example actually balanced at all lie angles). See the video I posted above.

[Wardonation]

Regarding LAB putters I know that the shaft angle is different for their cb putters compared to standard. CB shaft angle produces a loft of 3 degrees while standard model has a loft of 5.

[joostin]

Agreed with you and Howard.  I think the reason it's said it can be thrown off when changing length more than 1-2" is because of the desire to adjust headweight - like heavier for shorter or lighter for longer - while needing to do so with the weights in a way to maintain the head CG on the shaft axis.

 

This was my take on multiple types of torque, where "zero torque" can apply to that axial torque but not to everything.  The term seems to be taken as a blanket statement (like with "balance") as if there's only 1 torque when there's more to it:

 

 

[ChaosTheory]

17 hours ago, ShawLF said:

I know this topic has been discussed in the past with some stating that a LAB putter can be shortened by 1-2" without causing the putter to become unbalanced; however, this has never made sense to me since changing the length of the cylinder rotating around its lengthwise axis has no impact on axial torque or MOI. The only way I can see length having an impact on rotational torque would be if it caused the player to swing the club on a different lie angle.

 

Does anyone have a plausible explanation to support how changing the length causes the putter to become unbalanced?

I tend to agree.  The only reason I can see for the opposite view is the angled grip.  Sam the LAB man says swinging with the angled grip introduces no torque.  I feel that it must, but maybe it’s minimal. Or else they have balanced it out specifically, which would probably be length-dependent. The longer the shaft, the further ahead of the head’s COG is the center line of the grip.

 

 

[Stuart_G]

18 hours ago, ShawLF said:

This is a good demonstration of lie angle balanced. I can't see how the length of the shaft plays a role here.

 

It doesn't.   It's likely just the implied change in lie angle as the length changes they might be concerned about.

 

Any change in head weight is potentially going to effect the balance and a length change isn't the only source of a head weight change and they would have to deal with that separately anyways.

Edited April 26 by Stuart_G

[ShawLF]

1 hour ago, ChaosTheory said:

The only reason I can see for the opposite view is the angled grip.  Sam the LAB man says swinging with the angled grip introduces no torque.  I feel that it must, but maybe it’s minimal. Or else they have balanced it out specifically, which would probably be length-dependent. The longer the shaft, the further ahead of the head’s COG is the center line of the grip.

Yes I considered that as well and came to the same conclusion as you. The distance from the axis of rotation is relatively small and the weight of the grip is much less than the other parts. Plus, as long as the orientation of the grip was the same, it really shouldn't factor into it unless the shorter length causes the player to do something different.

 

I love the chaotic pendulum btw. I'm sure you've looked at how the chaos kicks in after the bottom node passes the middle node? A very good visual for demonstrating the value of forward shaft lean at impact. 

[ChaosTheory]

1 hour ago, ShawLF said:

Yes I considered that as well and came to the same conclusion as you. The distance from the axis of rotation is relatively small and the weight of the grip is much less than the other parts. Plus, as long as the orientation of the grip was the same, it really shouldn't factor into it unless the shorter length causes the player to do something different.

 

I love the chaotic pendulum btw. I'm sure you've looked at how the chaos kicks in after the bottom node passes the middle node? A very good visual for demonstrating the value of forward shaft lean at impact. 

 

I wasn't thinking of the weight of the grip, but the "line" of the hands, which is not the line of the shaft.   The longer the shaft, the farther ahead is the orientation of the hands.

 

I'm glad you like the pendulum!  It's like a brain scan of my golf swing thoughts.