OK I HAV MY SHAFT-PCE.
I searched throo my stockpile, and i found a 20-3/8" long Eliminator shaft that i had kut down years ago (originally 29") to make a masse-cue/nursery-cue.
It had a rubber qtip (originally a lepro) -- so yesterday i kut this off and glued on a 10mm elk.
The tip-end iz 10.1mm (zero ferrule)(originally 13.2mm with white plastic ferrule). Joint-end iz 21.6mm (0.850")(ie nontouched original).
The maple iz 12.7mm at 6", and 17.2mm at 12" -- allmost unuzeable (too conical) -- i will sand this down to near parallel.
Anyhow i hav my shaft-pce -- now i need a mid-pce -- and a butt-pce.
I will of course uze an Eliminator sneaky pete for the mid-pce.
Hencely measuring back 29" from the qtip the maple will be 24.7mm (0.972") -- in other words my 3pce cue will be 0.972" at mid-point -- ie 0.122" oversize (allmost 1/8"). This iz fat fat fat. I luvv it (just hope it aint too noze-heavy).
The mid-pce will be the first 20" of an Eliminator sneaky pete butt.
The butt-pce will I think be any old 20" lump of 1-1/8" hardwood rod.
A 20" bit of old or new shovel handle would do the trick.
But here we hav the opportunity of doing something special. I am thinking of having unique carved/turned patterns. For example some butt-pieces kood be spirals (az per the following link).
ARE FORCES ON JOINT 1 GREATER THAN FORCES ON JOINT 2 ??????????
Joint 1 iz just the original 5/16 18tpi maple to maple Eliminator midjoint, but at 20" not at 29".
Joint 2 will be at 40", and will be endangered-hardwood (original Eliminator butt) to rare-hardwood (probly 20" off an old shovel handle).
If the qtip to qball kontakt time woz 1/10,000th of a second (ie a 10kHz event), and if sound took 1/1000th of a second to travel from tip-end to butt-end, then a compression-wave 1/10th the length of the cue (ie 6" long) would travel from tip to butt -- and then return from butt to tip. Etc etc etc, but gradually loozing strength. I think that that iz the theory.
But I suspect that the initial compression-wave (mum) travelling down the cue would find herself followed by a tension-wave, which would be closely followed by another compression-wave etc etc (the kids). And when mum reeched the butt-end, she would be being followed by praps 3 tension-kids and 3 compression-kids. And then mum turns and during her return journey she would run into praps 12 of her kids (say 6 tension-kids and 6 compression-kids), which would all turn around at the butt-end and follow mum. The kids would be shorter and hav a different shape to mum -- mum haz a forced shape and size -- the kids would hav a more natural shape. Mum iz allways a compression-wave, and when mum meets a compression-kid their compressions add -- and when a tension-kid meets a tension-kid their tensions add.
But in the real world the kontakt-times tween balls and qtips are in the range 0.0005sec to 0.0015sec (say 1/1000th sec).
And a sound-wave in wood kan travel 4500m per second -- ie 4.5m during kontakt -- ie 3 lengths of a 1.5m cue. This ratio duznt work very well -- its an unhappy ratio. The hit would be more efficient if the cue woz much shorter -- or if the qtip woz much fatter and softer -- or if the shaftwood had a higher speed of sound.
Anyhow its too komplikated to imagin.
Its eezyer if one thinx of the impakt being 100 smaller impakts -- eech making its own little wave -- and then u add (or subtract). At mid-impakt (whatever that meens) the qtip iz travelling at the same speed az the ball (if we ignore strain and vibration in the ball).
Tension wouldn't worry a joint during impakt -- koz max tension would occur sometime after separation.
And compression wouldn't worry a joint during impakt -- koz joints are unlikely to fail in compression (tension iz the enemy of a joint).
However, bending and buckling would eech reeech a max sometime after impakt -- and such flexing-compression-stress adds to axial-compression-stress. But it would be the flexing-tension after impakt adding to axial-tension after impakt that would worry the joint-pin.
And what about a cue's taper.
Duzz the taper rezult in more stress in Joint 1 than in Joint 2 (koz Joint 1 iz thinner).
And, praps taper in some way concentrates the wave-force -- like a water-wave getting higher az it runs into shallow water. Or a bit like all of the energy of a leather whip getting concentrated at the thin end, where it breaks the sound barrier.
Tension iz the problem. Flexing-tension would be worse at Joint 1 koz the cue bends more here.
Axial-tension might be similar at all points along the cue -- however axial-tension-stress would probly be lesserer nearer the butt koz of the larger diameter. This might be so if there were no joint, but at a joint all tension iz in the pin, hencely the axial-tension-stress would depend on the dia of the pin (not the dia of the butt).
Hmmmmm -- if axial-tension-force iz the same at all points along a cue, then why don't rubber bumpers fly off -- they are uzually held by a thin little skrew.
Anyhow, I am going to uze a thin little wood skrew in Joint 2, and then see what happens.
One small joint for man, one giant leap for mankind.
Aktually, kommie cues, I meen DBK cues, haz some good 24000fps slo-mo showing a qtip hitting qball.
This iz the only footage that I hav ever seen showing the compression-waves/tension-waves in a cue.
If u hav a close look at the leather qtip u will see that after the ball leevs the qtip moovs backnforth axially for a while.
The backnforth waves appear to be at say 4kHz, ie 4000 waves per second.
Eech full wave haz a tension half, where the cue stretches -- and a compression half, where the cue shortens.
4000 full waves per second meens that sound travels 8000 lengths per second, ie 12000m/s.
4000wps iz only a guess. I based this on the fakt that the qtip iz supposed to be in kontakt with the qball for 1 millisecond (a 1kHz event) -- and I estimated that the qtip went backnforth 4 times in the same timespan (ie a 4kHz event). But the speed of sound in wood iz supposed to be 4600m/s -- not 12000m/s. So something iz awry.
In other footage (showing skrew shots etc) the qtip allso haz a little bit of backnforth moovment.
But this iz due to faux-shortening, ie due to bending and buckling. U kan see at least 2 or 3 obvious types of this flexing -- eech having its own period and sideways displacement -- all happening at the same time.
The 24000fps footage that I originally referred to shows a centerball hit with a leather qtip.
But even here (centerball hit) u kan see that the qtip haz a slow backnforth motion that must be due to buckling (ie not due to compression, ie it iz faux-compression) -- koz cues allways buckle, center hit or no.
I just thort of something.
Mightbe what I identyfyd az a buckling backnforth (faux-compression) motion actually iz the true axial compression/tension wave in the maple. Looking at that footage again, I see that the maple-waves are more like 2kHz. And mightbe the qtips backnforth 4kHz motion iz due to the leather qtip doing its own thing.
The qtips backnforth motion that I allude to iz actually mostly stretching of the leather.
The base of the leather qtip (ie the maple) duznt do anything much at all, but the tip of the qtip goze backnforth in a frenzy. The leather qtip goze fat then thin then fat etc etc -- there iz a lot of leather stretching going on (very eezy to see compared to the slower and smaller motion of the maple). I now think that mightbe the stretching etc of the leather haz its own life, with its own period etc, separate to the waves in the maple. The leather iz ringing. But i would expect it to ring with a frequency of at least say 40kHz, not 4kHz. Hmmmmmm -- seeing az the footage iz at 24kHz, there might be lots of leather-waves that go by unfilmed. If the footage woz at 240kHz then praps we would be able to count 40 leather-waves, not 4.
I made a 3pce sneaky pete Eliminator.
The shaft-pce iz 20-9/16" (I kut 8-7/16" off a 13.2mm Eliminator shaft) -- & the qtip iz now 9.4mm (English billiards here) -- joint iz original.
The mid-pce iz 22-11/16" (I kut 6-5/16" off an Eliminator butt). One day I will kut this down to under 21".
The butt-pce iz 18-13/16" (kut from a 35mm hardwood rod from a timber supply). I sanded this down to 30mm (using the lathe).
The overall L iz 62-1/16" (but ultimately i will reduce it to 60").
Overall wt iz 18.95oz .....(a bit low for me, i might add some).
Balance iz 37-5/16" from the qtip (this would be 20-11/16" from the end if the cue were 58" long which it aint).
Joint 1 iz the original Eliminator 5/16" 18tpi (stainless steel and brass sleeve) wood to wood joint (21.6mm, 0.850").
Joint 2 iz a homemade wood to wood joint (29mm, 1.142").
The pin iz a 3-1/2" length of 14-gauge self-tapping steel woodscrew (OD iz 1/4", 10tpi).
I drilled a 3/16" hole into the mid-pce and into the butt-pce (uzing the lathe).
Then i tapped a wood thread into eech hole.
For a tap i uzed a wood-skrew (ie the same sort of skrew uzed for the pin).
U karnt buy a wood-skrew tap, so i made my own. I uzed an angle-grinder to run a longi-groov along a skrew (to mimic a proper tap). And i tapered the leading end (to mimic a proper tap). Too eezy.
I sanded a nice square accurat end on the mid-pce (ie for Joint 2) uzing feel (the lathe aint got a proper square kutoff setup).
But the central hole running throo the wood lathe woznt big enuff to accommodate the butt-pce, and there woz so much butt-pce sticking out of the lathe that i koodnt sand a square end in a similar fashion to the way i sanded the mid-pce, so i hadta sand the 90dg end (for Joint 2) by trial and error, az follows.
Getting a straight fit at Joint 2 woz diffikult.
I hadta gradually (by trial and error) sand the face on the butt-pce until the mid-pce and butt-pce joined dead straight.
At the same time, i painted a stain onto the face of the mid-pce -- and this rubbed onto the butt-pce and showed hi-points for sanding.
The 14-gauge 10tpi wood skrew duznt make an ideal pin for Joint 2.
10tpi duznt giv u much compression in the joint (18tpi would be better).
And a hi-strength self-tapping wood skrew kan az we all know break any time it likes.
And 1-3/4" of wood thread in eech of the mid-pce and the butt-pce iz a bit iffy, the pin might pull out one day.
Anyhow time will tell.
I hav 3 short shafts suitable for my 3pce cue -- hencely i kan pick the best (and 2 kan be spares). I just then glued three new elk qtips on these three shafts (uzing 5 minute araldite), and they are prezently cooking over a hot globe (to get hi strength).
Now i havta shop around for a short cue-case, or a short quiver of some sort (otherwise i might az well tote my 2pce).
Pix shows Shaft-pce and Mid-pce and Butt-pce -- next to an original Eliminator shaft and butt.
Mid-pce will be shortened by 2" later -- and Shaft-pce might be shortened also.
Butt-pce will hav fat end thinned later.
Pix shows Joint 1 and Joint 2.
Joiner Pin iz 1/4" 10tpi 14gauge woodscrew 3-1/2" long.
Allso shows woodscrew uzed az a thread tap.
Shows my brother's shed after I kleened it up and uncovered the lathe.
The front end loader used to be a Datsun family sedan (did u see it in Mad Max).
Pix shows modern conversion to electrical power.
Original lathe woz one horsepower (ex Civil War).
Hey mac - several cuemakers build 3-piece cues. I have one from Sheldon Lebow (a sneaky pete, three equal lengths) and from Andy Gilbert (4-point, three equal lengths).
Originally Posted by cushioncrawler
John Barton made my 22" case for it.