Bill Porter,
Thanks for the email heads up about this thread! I really like these kinds of discussions.
I am surprised that there seems to be so much variation in some of the LD shafts. I haven't measured every shaft that we have produced, but ours have really held pretty steady. Our non insert shafts run from 3.5 to 3.7 ounces, leaning more to the 3.5 side. Our insert shafts run 3.7 to 3.9 ounces, again leaning closer to the lower number more often.
I have been doing some calculations on what kind of a difference adding weight will make to our cue shafts. The neat thing is that you can calculate the balance point of the cue if you have the weight and the balance point of each of the parts, the butt and the shaft.
My cue weighs 19 ounces and balances at 19" from the butt, which is my preference by the way. It is our 308 Model with an OB-2 cue shaft.
The formula is actually a calculation of torque around a fixed point. I use the butt end of the cue for that point. Basically, you weigh each part and find it's balance point. Then you determine the distance from that balance point to the butt end of the cue. The formula looks like this:
M1 = Mass of the cue shaft
L1 = Length from the shaft balance point to the end of the cue (the butt)
M2 = mass of the butt
L2 = Length of the butt balance point to the end of the cue
(M1*L1)+(M2*L2)
divided by
M1*M2
This gives the overall balance in inches from the back of the cue.
My cue works like this
(3.7*39.5)+(15.1*14)
divided by
3.7*15.1
Equals 19.0 inches
If I add .4 ounces to the shaft, at the joint the numbers look like this
(4.1*38.5)+(15.1*14)
divided by
4.1*15.1
Equals 19.2 inches, or a difference of .2 inches
The funny thing is that most conventional shafts have a much fatter and thicker taper than our cue shafts and many other LD shafts. I believe that a significant amount of the weight difference comes from the taper. The same 4.1 ounce shaft that balances 1 inch closer to the tip will move the balance point of the cue another .2 inches.
So, I guess the conclusion is that yes, LD shafts that are lighter than conventional shafts will change the balance point of the cue, but typically it will be a small amount, no more than .4" in the numbers I gave here. But, if a player uses a conventional cue shaft that uses a longer thinner taper, moving to a LD shaft may not change it very much, if at all. Often, what a player is looking for is the thinner taper, so he will change his balance point even with a conventional type of shaft.
I hope that answers some questions, or at least creates some!
Royce Bunnell
www.obcues.com