The BIG low deflection Hype Campaign.

[dr_dave]

Since Dave was the one stating it in inches that is what I used understanding that it would be the weight to a certain point behind the tip but thank you for pointing it out.

Again, it is not just a simple weight measurement over a specific length, per my previous post.

Regards,
Dave

 

[Matt]

The idea that the sound wave speed should be roughly equal does not hold water if you are looking to quantify deflection because, as shown by the US Forest Products Lab testing, the speed of sound propagation through Maple can vary considerably. Unless you use this actual speed, along with mass, to compute what deflection is, then the answer is not going to be correct. It is also going to vary with shafts from the same maker so a number obtained in one shaft does not necessarily mean that all shafts measure the same and unless certain parameters in wood preparation are met than the numbers absolutely will vary considerably.
Also, all high (LD) deflection shafts are not built the same. The point(s) that the shaft is bending from would also make a difference as while the last 4" of the shaft might be extremely light the area directly behind that might be extremely stiff.
Once again, the testing done by Barioni, shown here on AZB and ridiculed by most, came to somewhat different conclusions than what is thought to be 'common knowledge'.

I guess I should have defined what I mean by "roughly"...

rough·ly
ˈrəflē
adverb
2. in a manner lacking refinement and precision.
synonyms: approximately, about, round/around about, around, circa, in the region of, something like, in the order of, or so, or thereabouts, more or less, give or take; nearly, close to, approaching

Although the speed of sound propagation through maple may "vary considerably", that variation, especially among maple that has been turned into a cue shaft, still fits within my use of the word "roughly" when I was implying that the variation in the distance the wave propagates down the shaft during impact would be on the order of a couple inches. If you wanted to accurately characterize a particular shaft, I agree that you would have to precisely measure that speed. In your example of a very light area followed by a very stiff area, the stiffness would factor into the wave propagation speed (and likely the mass) and thus the effective endmass.

The point is that the part of the shaft that affects squirt is limited to some distance from the tip, so anything done to the cue beyond that point is not a factor.

 

[dr_dave]

I remember Efren saying no LD shafts for me, in a interview called what is in your case in Japan. In the interview Efren talked about how many shafts he brought with him and what kind they were. He had one solid maple, and he had another solid maple shaft being made for him in PI. It also seemed even if Efren did have a problem with a shaft that he could of borrowed one a pretty much shot with any solid maple shaft.
His confidence was in himself and not really into fancy equipment
At that time Efren was world 9 ball champion.

Everyone has to compensate for deflection................

LD shafts are weaker............... because of the reduced mass.

You are correct. LD shafts have disadvantages for some people.

What makes LD shafts better then a normal solid maple ?
What can a LD shaft do that a Solid maple shaft cannot do ?

Here is a list of the advantages an LD shaft offers.

LD shafts have less deflection but still have to compensate, JUST like a solid maple shaft.

That is correct, but less compensation is required. When there is less compensation, the error in the compensation will be less. That's the main advantage. For more info, see Diagram 2 and the surrounding discussion in "Squirt - Part V: low-squirt cues" (BD, December, 2007).

Regards,
Dave

 

[dr_dave]

Although the speed of sound propagation through maple may "vary considerably", that variation, especially among maple that has been turned into a cue shaft, still fits within my use of the word "roughly" when I was implying that the variation in the distance the wave propagates down the shaft during impact would be on the order of a couple inches. If you wanted to accurately characterize a particular shaft, I agree that you would have to precisely measure that speed. In your example of a very light area followed by a very stiff area, the stiffness would factor into the wave propagation speed (and likely the mass) and thus the effective endmass.

The speed of sound in maple relates directly only to the speed of the "longitudinal" wave (done the length of the cue). This wave travels very quickly from the tip to the joint and butt end and back while the tip is in contact with the cue ball. If it didn't, the entire weight of the cue wouldn't come into play during the collision (but it does).

The wave that is important to squirt is the "transverse" or "lateral" elastic wave, which corresponds to deflection of the tip perpendicular to the shaft (in the squirt direction). This wave moves much more slowly than the longitudinal wave. FYI, some videos and articles on this topic can be found here: cue vibration resource page.

The point is that the part of the shaft that affects squirt is limited to some distance from the tip, so anything done to the cue beyond that point is not a factor.

Right. And the closer to the tip, the greater the effect.

Regards,
Dave

 

[bdcues]

I remember Efren saying no LD shafts for me, in a interview called what is in your case in Japan. In the interview Efren talked about how many shafts he brought with him and what kind they were. He had one solid maple, and he had another solid maple shaft being made for him in PI. It also seemed even if Efren did have a problem with a shaft that he could of borrowed one a pretty much shot with any solid maple shaft.
His confidence was in himself and not really into fancy equipment
At that time Efren was world 9 ball champion.

Everyone has to compensate for deflection................

LD shafts are weaker............... because of the reduced mass.

What makes LD shafts better then a normal solid maple ?
What can a LD shaft do that a Solid maple shaft cannot do ?


Solid maple shafts cost less, They are stronger and normally will out live any laminated LD shaft.
The ferrules and joint areas are stronger, and I do not think any glue will hold up like wood does year after year.

LD shafts have less deflection but still have to compensate, JUST like a solid maple shaft.

You are making generalizations once again.

 

[Matt]

The speed of sound in maple relates directly only to the speed of the "longitudinal" wave (done the length of the cue). This wave travels very quickly from the tip to the joint and butt end and back while the tip is in contact with the cue ball. If it didn't, the entire weight of the cue wouldn't come into play during the collision (but it does).

The wave that is important to squirt is the "transverse" or "lateral" elastic wave, which corresponds to deflection of the tip perpendicular to the shaft (in the squirt direction). This wave moves much more slowly than the longitudinal wave. FYI, some videos and articles on this topic can be found here: cue vibration resource page.

Good point. I'm not a materials guy, but it looks like the "specific modulus" of the material is what determines the stiffness if the shape is the same. Measuring the frequency of the transverse wave is certainly easier than characterizing all of the components and trying to calculate it. It looks like you've done that for at least one cue. Are there results for multiple cues?

 

[dr_dave]

The wave that is important to squirt is the "transverse" or "lateral" elastic wave, which corresponds to deflection of the tip perpendicular to the shaft (in the squirt direction). This wave moves much more slowly than the longitudinal wave. FYI, some videos and articles on this topic can be found here: cue vibration resource page.

Good point. I'm not a materials guy, but it looks like the "specific modulus" of the material is what determines the stiffness if the shape is the same. Measuring the frequency of the transverse wave is certainly easier than characterizing all of the components and trying to calculate it. It looks like you've done that for at least one cue. Are there results for multiple cues?

I don't have anything beyond what is on the resource page.

Sorry,
Dave

 

[jtaylor996]

I remember Efren saying no LD shafts for me, in a interview called what is in your case in Japan. In the interview Efren talked about how many shafts he brought with him and what kind they were. He had one solid maple, and he had another solid maple shaft being made for him in PI. It also seemed even if Efren did have a problem with a shaft that he could of borrowed one a pretty much shot with any solid maple shaft.
His confidence was in himself and not really into fancy equipment
At that time Efren was world 9 ball champion.

Everyone has to compensate for deflection................

LD shafts are weaker............... because of the reduced mass.

What makes LD shafts better then a normal solid maple ?
What can a LD shaft do that a Solid maple shaft cannot do ?


Solid maple shafts cost less, They are stronger and normally will out live any laminated LD shaft.
The ferrules and joint areas are stronger, and I do not think any glue will hold up like wood does year after year.

LD shafts have less deflection but still have to compensate, JUST like a solid maple shaft.

Efren usually uses a Judd Fuller JT-1, with an "efren" taper, which is super long and skinny. This taper is probably at least as low deflection as a predator Z.

 

[JoeyInCali]

Efren usually uses a Judd Fuller JT-1, with an "efren" taper, which is super long and skinny. This taper is probably at least as low deflection as a predator Z.

Efren's changed shaft taper . He uses a Mezz shaft that is much stiffer than what he used to play with. I was actually shocked when I saw it.
I think it'd be reaaaalllly hard for a normal shaft to have less squirt than the Pred Z shaft. It might be impossible too.

 

[jtaylor996]

Efren's changed shaft taper . He uses a Mezz shaft that is much stiffer than what he used to play with. I was actually shocked when I saw it.
I think it'd be reaaaalllly hard for a normal shaft to have less squirt than the Pred Z shaft. It might be impossible too.

Actually, he had switched back to the JT-1 as of a month ago... I remember reading about the mezz thing, though.

I have a solid Libra shaft on a different cue that plays even better than my Z2. I may read up on Dave's site to figure out to measure the deflection just to see how close it is as far as deflection goes. I just had Steve Klein cut one of my Judd shafts to match that Libra. Gonna pick it up tomorrow, so maybe I can get some measurements tomorrow night.

 

[dr_dave]

I may read up on Dave's site to figure out to measure the deflection just to see how close it is as far as deflection goes

Good idea. I wish other people with various claims or things they want to test would do this also. It isn't that difficult (although, it does take some time to do tests carefully).

You don't really need to read anything. Just watch the beginning of the following video:

NV D.15 - Cue and Tip Testing for Cue Ball Deflection (Squirt)

Here's the rail ruler template used in the video if you want to print it.

Have fun and let us know how it goes,
Dave

 

[GoBilliards]

I remember Efren saying no LD shafts for me, in a interview called what is in your case in Japan. In the interview Efren talked about how many shafts he brought with him and what kind they were. He had one solid maple, and he had another solid maple shaft being made for him in PI. It also seemed even if Efren did have a problem with a shaft that he could of borrowed one a pretty much shot with any solid maple shaft.
His confidence was in himself and not really into fancy equipment
At that time Efren was world 9 ball champion.

Everyone has to compensate for deflection................

LD shafts are weaker............... because of the reduced mass.

What makes LD shafts better then a normal solid maple ?
What can a LD shaft do that a Solid maple shaft cannot do ?


Solid maple shafts cost less, They are stronger and normally will out live any laminated LD shaft.
The ferrules and joint areas are stronger, and I do not think any glue will hold up like wood does year after year.

LD shafts have less deflection but still have to compensate, JUST like a solid maple shaft.

Efren used to play with a tip that I thought was an elk master and he had a metal washer glued on first.(Between the tip and ferrule). This would be the opposite of lightening the end closest to the tip. obv.

 

[336Robin]

Point Made

I am not sure I understand your point, because shots at that distance don't require adjustment with a standard shaft either. The cue ball squirts when you apply side spin and you have to adjust for it, no matter what shaft you use. It is a measurable phenomenon, and people have measured it. Kind of hard to deny. The point I was trying to make is that the difference is less than a lot of people think it is.

If you really look at the video I was talking about, and actually think about the results, you can see that a shot at maximum cue ball to object ball distance and maximum tip offset showed a difference of a half ball width between the different types of shafts. As you pointed out, squirt becomes less of a factor at when you shorten these distances, or use less english. That suggests to me that there is probably not much practical difference between these shafts for around 70% of possible shots.

I don't have any problem admitting that LD shafts work as advertised, but I am not ready to attribute any magical properties to them.

Omar,
You make quite a point and more especially if you play your English to the size of nickel that reduces deflection a lot but still supplies some spin.

I cant seem to make myself stay that close to the center, it just feel natural to go outside to max. I have to make myself do it.

 

[jburkm002]

I think it would be interesting to come up with a standard test anyone can do. Not only where the cue hits on the foot rail but also the side rail. I also think the test would be best with two players testing the same equipment when possible. Maybe I do the test with my cues and his cues and he does the same. The reason being is even though some deflection is natural. I also believe some is self induced. So it would be good to see separate results with someone else stroke with the same equipment.

 

[dr_dave]

I think it would be interesting to come up with a standard test anyone can do. Not only where the cue hits on the foot rail but also the side rail. I also think the test would be best with two players testing the same equipment when possible. Maybe I do the test with my cues and his cues and he does the same. The reason being is even though some deflection is natural. I also believe some is self induced. So it would be good to see separate results with someone else stroke with the same equipment.

That's a great idea. I recommend the procedure described and demonstrated here:

NV D.15 - Cue and Tip Testing for Cue Ball Deflection (Squirt)

The test is easy to set up, and it doesn't require any special equipment.

Regards,
Dave