My 3pce balance iz an inch or two noze-heavy (compared to standard)(even with that ubeaut Eliminator 5/16-18 Joint1) -- i kood fix that by shaving off lots of maple, but that would reduce stiffness (and getting extra stiffness woz the primary goal which got me going on this 3pce stuff, getting a tote-able small cue-case woz allways a secondary consideration).
But praps I am getting used to the noze-heavyness (and so kood anyone). Anyhow no cue iz very noze-heavy to me koz i hold the cue much shorter than anybody (mainly koz of the forward angle of my hand, but that's another story).
But getting back to krappy stalin-joints, i reckon that magnesium (SG 1.74) would be better koz it iz lighter than titanium (SG 4.5)(when uzing same sized pin). Hell, Bakelite (phenolic rezin) haz a SG of 1.7 (and magnesium iz much stronger)(maple's SG iz say 0.70).
None of this would make much difference to my 3pce cues koz the steel pin (wood skrew) in my homemade Joint2 only adds about 0.43oz to the cue wt -- the sound-wave would hardly know it woz there. And the 5/16-18 in Joint1 only adds praps 1oz.
Anyhow the plain linseeded look of the (stringybark or peppermint) light brown wide-grained butt-pce of mine looks very nice. I wont be painting it. But i might burn on some discreet little rings (and praps some rarrk) near the ends in an indigenous (didgeridoo) fashion.
Last edited by cushioncrawler; 01-10-2014 at 07:52 AM.
Acoustics Of Wood by Voichita Bucur iz a good read on Google books (free preview to page 108).
Attenuation of sound in wood iz due to absorption (lignen iz bad news) and scattering (reflection and refraction) and radiation (macroscopic boundaries). Very complicated stuff.
Q1. Kan an ultrasound tell the sex of a joint??
Inkreecing moisture content inkreeces the internal friction (attenuation).
Inkreecing temperature inkreeces the internal friction (attenuation).
Inkreecing the angle of the grain inkreeces the internal friction (attenuation).
Hencely the straighter the grain the better. Attenuation across the grain (R) and (T) iz 2 to 3 times with the grain (L)(longitudinal).
Speed of sound across the grain (R) and (T) iz also approx 1/3rd of (L). (R) iz radially across, (T) iz tangentially across.
Zinc-treatment halves internal friction (attenuation).
It duzz so with some other timbers, so i am guessing that it might do likewize with maple. If so then praps u kan get super-maple if u treat with zinc. But praps zinc-treatment karnt be done with solid wood (ie praps zinc-treatment iz only applicable to chips or veneers). Anyhow, if u kood halve the internal friction (attenuation) of maple (giving super-maple) then what difference would this make to a cue. Would super-maple be stiffer?? Would it hit better??
If zinc crosslinking of "whatever" inkreeces the speed of sound by a factor of 2 then it must inkreec youngs modulus by 4
(see equation for speed of sound = E^0.5).
If youngs modulus iz inkreeced by 4, then the buckling of the cue iz dekreeced by 4 (see eulers equation for a long column = E^1).
U kan get a 4-fold inkreec in a cue's buckling strength (and bending strength) if u inkreec the diameter (near midpoint) by 1.4141 (ie 41.41%)(see equation for second moment of area of circle = D^4). (U kan get a 2-fold inkreec if u inkreec dia by 1.1892).
So, zinc might inkreec the stiffness of a cue by 4 (using super-maple), or u kood achieve the same stiffness if u thicken
an (ordinary-maple) cue by 41% (not practicable).
My 3pce cues are 16.28% thicker near midpt (and 1.1628^4 = 1.8281), ie an 83% inkreec in stiffness (if all else equal).
Q2. U throw a cue like a spear into a wall throwing harder and harder until it breaks -- where will it break??
Q3. U suspend a cue at eech end (horizontally), and u bend and break the cue by adding a wt -- where would u apply the wt such that u only needed the smallest possible wt??
Q4. In Q3 -- where would the cue break??
Euler knew that dekreecing the length of a 58" cue by 1" inkreeces the buckling strength by (=L^-0.5) or 1.0354 (3.54%).
A 56" cue would giv 1.0727 (an inkreec of 7.27%). Hencely (az Euler well knew), a shorter cue hits better.
The difference tween a 56" cue and a 60" cue iz 1.1480 (14.8%). Tween 60" and 56" iz 0.8711 (12.89%).
My 3pce cues are mostly 60", praps i shood make them 56" (it wouldn't make a lot of diff to the balance).
Cuesmiths uze rock maple and ignore other maples, yet the difference in density and strength and youngs modulus
tween maples iz (i think) very little. Or at least the differences in ratios iz very little. And the speed of (L) sound (in maple etc) iz inversely related to the square root of density (=1/density^0.5), and iz related to the square root of youngs modulus (=E^0.5)(here E iz in the (L) direction). Hencely the speed of sound in rock-maple iz probly little different to other types of maple -- other maples are denser, but they are allso stronger (stiffer)(i think).
Last edited by cushioncrawler; 01-10-2014 at 06:56 PM.
I am looking into cheap instruments for measuring the speed of sound in wood and cues. This site mentions some good stuff.
Not forgetting that musicians are mostly hearing low-speed (and low-frequency) bending-waves, whereaz cuesicians are interested in hi-speed (and potentially hi-frequency) compression waves (longitudinal).
Last edited by cushioncrawler; 01-12-2014 at 11:40 PM.
Lets say that MapleCC iz third-rate (wide-grained) and iz 75% the density (SG/SG) of first-rate MapleAA,
and lets say the strength/strength of MapleCC iz 75% of MapleAA.
Thusly a MapleCC cue kood be (4/3)^0.5 = 1.1547 az thick az a MapleAA cue yet be the same wt (koz if L iz the same, then wt goze by area, and area goze by D^2).
If D/D iz 1.1547, then the second moment of area for MapleCC iz ((4/3)^0.5)^4 = (4/3)^2 = 16/9 = 1.7777 that of MapleAA (koz smoa goze by D^4).
If strength/strength iz 3/4, & if the smoa/smoa iz 16/9, then stiffness/stiffness of MapleCC iz 3/4 of 16/9 = 4/3 = 1.3333
kompared to the stiffness of MapleAA. This iz for a two cues having the same wt (which by the way will hav the same balance).
Stiffness here meens stiffness rezisting bending (az in a beam), and it allso meens stiffness rezisting buckling (az in a column)(bending/bending and buckling/buckling enjoy the same proportions and ratios and komparisons (i think), even tho the engineering equations for bending and for buckling are very different in other ways).
But the stiffness of a cue depends mainly on the mid-thickness. Hencely u kood up that 1.3333 a hell of a lot.
U kood giv the CC-cue AA-cue-thickness at eech end but more thickness at the midpt (ie D/D would then be more than 1.1547). Here u would be taking CC-wood from the tip-end & adding CC-wood to the mid-area of your CC-cue. This kood make the CC-cue the same wt az the AA-cue (if u like)(if take = add).
Just in case u were wondering, this would actually make the balance of the CC-cue noze-lite kompared to the AA-cue (this iz probly counterintuitive). Hencely u kood add even more CC-wood at midpt, and then u might achieve the same balance (if u like)(but then the CC-cue would be a bit heavyer than the AA-cue).
Anyhow, based on the above thinking, a wide-grained log (of maple or ash or ??) that might be graded CC might make
a better cue than an AA (narrow-grained) log, if only u were prepared to make use of the lite-wt by thickening the mid-area of the cue.
This stuff might help to explain things i sayd much earlyer (when i woz badmouthing AAA maple, and praizing Bgrade maple).
But don't uze wood that haz a crooked grain, or wood that iz from a weak or heavy part of the log.
The abov stuff relates to all cues, 1pce cues, 2pce cues, 3pce cues, all cues, with any type of joint (inklooding stalin-joints).
I havnt mentioned speed of sound. The speed of sound in (any) wood iz irrelevant.
We are only interested in the speed of sound in cue-wood when we don't know much about the wood. The speed of sound tells us things about the wood. The speed of sound in wood iz just a short-kut way of smelling the soup. If u know all of the ingrediants (propertys) of the soup then u will be in a better pozzy to guess the taste (but a sniff wont hurt).
However, if someone knows how sound (longi-sound and radial-sound and tangential-sound) might affekt hit, and/or other propertys of sound (attenuation-Q, resonance, ringing, reflection, refraction, absorption, natural wave-length etc), then i am all ears.
Last edited by cushioncrawler; 01-12-2014 at 11:38 PM.
From Wikipedia, the free encyclopedia
For "attenuation coefficient" as it applies to electromagnetic theory and telecommunications see propagation constant. For the "mass attenuation coefficient", see the article mass attenuation coefficient.
The attenuation coefficient is a quantity that characterizes how easily a material or medium can be penetrated by a beam of light, sound, particles, or other energy or matter. A large attenuation coefficient means that the beam is quickly "attenuated" (weakened) as it passes through the medium, and a small attenuation coefficient means that the medium is relatively transparent to the beam. Attenuation coefficient is measured using units of reciprocal length.
The attenuation coefficient is also called linear attenuation coefficient, narrow beam attenuation coefficient, or absorption coefficient. Although all four terms are often used interchangeably, they can occasionally have a subtle distinction, as explained below.
The attenuation coefficient describes the extent to which the intensity of an energy beam is reduced as it passes through a specific material. This might be a beam of electromagnetic radiation or sound.
It is used in the context of X-rays or Gamma rays, where it is represented using the symbol \mu, and measured in cm−1.
It is also used for modeling solar and infrared radiative transfer in the atmosphere, albeit usually denoted with another symbol (given the standard use of \mu = \cos(\theta) for slant paths).
In the case of ultrasound attenuation it is usually denoted as \alpha and measured in dB/cm/MHz.
The attenuation coefficient is widely used in acoustics for characterizing particle size distribution. A common unit in this contexts is inverse metres, and the most common symbol is the Greek letter \alpha.
It is also used in acoustics for quantifying how well a wall in a building absorbs sound. Wallace Sabine was a pioneer of this concept. A unit named in his honor is the sabin: the absorption by a 1-square-metre (11 sq ft) slab of perfectly absorptive material (the same amount of sound loss as if there were a 1-square-metre window). Note that the sabin is not a unit of attenuation coefficient; rather, it is the unit of a related quantity.
A small linear attenuation coefficient indicates that the material in question is relatively transparent, while a larger value indicates greater degrees of opacity. The linear attenuation coefficient is dependent upon the type of material and the energy of the radiation. Generally, for electromagnetic radiation, the higher the energy of the incident photons and the less dense the material in question, the lower the corresponding linear attenuation coefficient will be.
Last edited by cushioncrawler; 01-15-2014 at 07:55 PM.
Attenuation coefficient [wikileaks]
Attenuation coefficients are used to quantify different media according to how strongly the transmitted ultrasound amplitude decreases as a function of frequency. The attenuation coefficient (\alpha) can be used to determine total attenuation in dB in the medium using the following formula:
As this equation shows, besides the medium length and attenuation coefficient, attenuation is also linearly dependent on the frequency of the incident ultrasound beam. Attenuation coefficients vary widely for different media. In biomedical ultrasound imaging however, biological materials and water are the most commonly used media. The attenuation coefficients of common biological materials at a frequency of 1 MHz are listed below:
Air 1.64 (20°C)
Bone, cortical 6.9
Bone, trabecular 9.94
Connective tissue 1.57
Soft tissue (average) 0.54
There are two general ways of acoustic energy losses: absorption and scattering, for instance light scattering.
Ultrasound propagation through homogeneous media is associated only with absorption and can be characterized with absorption coefficient only.
Propagation through heterogeneous media requires taking into account scattering.
Fractional derivative wave equations can be applied for modeling of lossy acoustical wave propagation, see also acoustic attenuation and Ref.
Last edited by cushioncrawler; 01-17-2014 at 07:48 PM.
Hencely i expect that ivory would act like dentin and enamel, ie having a terrible absorption. No good for joints or ferrules.
This would help explain why ivory balls sound az if they are twice az hard az Bakelite balls, whereaz ivory iz praps say half az hard.
Bakelite haz a coefficient of i think 4.86.
Maple possibly 0.02 to 0.06 (dunno, still looking).
Last edited by cushioncrawler; 01-17-2014 at 08:41 PM.
Most of the experts suggest two-piece cues for pool as they are easy to transport. However, make sure that the joint between the two pieces doesn't hamper the performance of your game.
Nah, its 3pce for me from now on, but 4pce might be better on the subway.
I havnt been praktising much since Xmas, but will start soon -- competition starts in 2 wks -- i will see what my teammates think ovem.