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Artemus
12-06-2007, 04:34 PM
Dave, I have a new challenge for you and like thinkers regarding the subject of shaft flex. Take a break from squirt, throw, swerve, etc. for a little while.

What kinds of test do you think would be required and specific numbers to determine a somewhat industry accepted standards regarding shaft flex for varying degrees?

I think up until now, a few cuemakers have built a shaft deflection board and attached a weight to the end, but that seems better suited for other sports equipment than a pool shaft.

You hear individuals refer to certain shafts as "whippy" and others as stiff as "rebar". Shouldn't the flex of a pool shaft be measured in a linear fashion based on impact speeds of a known CB weight (6 oz) as opposed to a sideways bending of an attached weight?

Would any so-called "whippy" shaft be very flexible at a slow to medium stroke speed? How hard would you have to hit a ball for it to be whippy and actually see this occurring?

I'd be interested to see if you could come up with something that would greatly impact how shafts are made, perceived, perform, and are bought and sold.

All ideas accepted from everyone in the think tank.

SKennedy
12-06-2007, 04:43 PM
What's the pay for working in this R&D department?

Artemus
12-06-2007, 05:22 PM
Is that the first question you would ask in an interview? /ccboard/images/graemlins/smile.gif

What can you bring to the table? /ccboard/images/graemlins/grin.gif

dr_dave
12-06-2007, 05:29 PM
<blockquote><font class="small">Quote Artemus:</font><hr> Dave, I have a new challenge for you and like thinkers regarding the subject of shaft flex. Take a break from squirt, throw, swerve, etc. for a little while.

What kinds of test do you think would be required and specific numbers to determine a somewhat industry accepted standards regarding shaft flex for varying degrees?

I think up until now, a few cuemakers have built a shaft deflection board and attached a weight to the end, but that seems better suited for other sports equipment than a pool shaft.

You hear individuals refer to certain shafts as "whippy" and others as stiff as "rebar". Shouldn't the flex of a pool shaft be measured in a linear fashion based on impact speeds of a known CB weight (6 oz) as opposed to a sideways bending of an attached weight?

Would any so-called "whippy" shaft be very flexible at a slow to medium stroke speed? How hard would you have to hit a ball for it to be whippy and actually see this occurring?

I'd be interested to see if you could come up with something that would greatly impact how shafts are made, perceived, perform, and are bought and sold.

All ideas accepted from everyone in the think tank. <hr /></blockquote>I will add this to my list, but I have several other high-priority items on my list I want to do first (after I finish my series of articles on squirt).

Before I would want to study shaft "stiffness" or "whippy-ness" I would want to know why people think these factors are important. A stiffer shaft usually has more end-mass, which will result in more squirt. It also has a different "feel" due to how the shaft vibrates after a hit. A stiffer shaft might also be stronger and more suitable for a certain style of play.

Do people have other suggestions for why shaft stiffness is important? For example, does anybody think it affects playability (other than squirt)? If you think it affects aspects of "feel," try to describe what you mean.

Regards,
Dave

Artemus
12-06-2007, 05:45 PM
<blockquote><font class="small">Quote dr_dave:</font><hr>
Before I would want to study shaft "stiffness" or "whippy-ness" I would want to know why people think these factors are important. A stiffer shaft usually has more end-mass, which will result in more squirt. It also has a different "feel" due to how the shaft vibrates after a hit. A stiffer shaft might also be stronger and more suitable for a certain style of play.

Do people have other suggestions for why shaft stiffness is important? For example, does anybody think it affects playability (other than squirt)? If you think it affects aspects of "feel," try to describe what you mean.
Regards,
Dave <hr /></blockquote>

Maybe college professors don't think in terms of making money and entrepeneurial spirit, but if you came up with a device or mechanism that could measure it accurately, I would venture to say that every cuemaker would be interested in purchasing it and the way shafts are categorized and sold. SQUIRT ISN'T EVERYTHING.

If it didn't affect playability, why would so many players have strong feelings one way or another regarding a Meucci shaft? There are those that swear a Meucci can do things with the CB that no other shaft can do. And there are those that hate them with a passion as being too "whippy" and there's no way to determine it.

Has anyone ever had a shaft that played TOO stiff? Why don't we start using titanium or some other metallic composite even stiffer if stiff is good.

Btw, I thought stiffness had more to do with density of the wood and the taper of the shaft. What does end mass have to do with a spliced shaft that's glued together with rock hard epoxy? What's the bending factor of epoxy even if a shaft is hollow.

wolfdancer
12-06-2007, 06:15 PM
I read somewhere, quite a while back, that computer testing validated Bob Muecci's theory on shafts....let them vibrate like a tuning fork, so to speak.
Something has to give on an off center hit....either the shaft, or the cue-ball, and without an unyielding shaft, it's a combination of both, I believe.
I think everybody that has their own cue, one that "fits" their stroke...has figured out the aim adjustment, and if another shaft was needed, would like it to play the same. Over the years, I've had a "second" shaft that played a little different.
As for knowing which cue has the greater flex.....that might be good to know...for buying a cue say, online, one you can't try out in advance.

SKennedy
12-06-2007, 07:07 PM
At my age and experience? Absolutely. Unfortunately, not on this topic. I'll have to recuse myself!
So, what's my severance package?

cushioncrawler
12-06-2007, 09:47 PM
<blockquote><font class="small">Quote Artemus:</font><hr>...Has anyone ever had a shaft that played TOO stiff? Why don't we start using titanium or some other metallic composite even stiffer if stiff is good....<hr /></blockquote>Stiff iz good. Everything iz good, and everything iz bad. A stiffy iz very good for stun (if the cue iz heavy allso).

A stiffy iz bad for screw (if the cue iz heavy allso) -- u havta have a facile-stroke with a big flourishy finish to get much screw or side, it feels like every such shot iz a horizontal masse. Try uzing a full-butt or a 3/4-butt (ie the long-stuff for a 12' table, ie thick &amp; stiff) to play a screw shot -- u karnt do it -- all u get iz stun -- in fact u wont get the qball to roll unless the range to the OB iz a mile, it seemz to defy phyzics, it never ceases to amaze even me.

The Apollo steel (hollow) cue woz a failure (in about 1970??), koz it woz too stiff (English billiards and snooker). They then made MK2 a 2-piece cue so that they could uze a plastic joiner insert to take out some stiffness, but still no cigar. madMac.

cushioncrawler
12-06-2007, 10:06 PM
<blockquote><font class="small">Quote Artemus:</font><hr> Dave, I have a new challenge for you and like thinkers regarding the subject of shaft flex. Take a break from squirt, throw, swerve, etc. for a little while.

What kinds of test do you think would be required and specific numbers to determine a somewhat industry accepted standards regarding shaft flex for varying degrees?

I think up until now, a few cuemakers have built a shaft deflection board and attached a weight to the end, but that seems better suited for other sports equipment than a pool shaft.

You hear individuals refer to certain shafts as "whippy" and others as stiff as "rebar". Shouldn't the flex of a pool shaft be measured in a linear fashion based on impact speeds of a known CB weight (6 oz) as opposed to a sideways bending of an attached weight?

Would any so-called "whippy" shaft be very flexible at a slow to medium stroke speed? How hard would you have to hit a ball for it to be whippy and actually see this occurring?

I'd be interested to see if you could come up with something that would greatly impact how shafts are made, perceived, perform, and are bought and sold. All ideas accepted from everyone in the think tank. <hr /></blockquote>I agree that an axial-impakt-test might be good. For instance we might test the (1) flex (near the tip) , (2) total wt, (3) balance pt, (4) natural vibrational frequency (near the tip), (5) other stuff, but if a cue haz a bad bend then it will lack "power" -- an axial test of some sort might show/measure any lack of power due to (a) a bend, (b) weakness, (c) low wt. madMac.

Heretic
12-07-2007, 01:33 AM
<blockquote><font class="small">Quote dr_dave:</font><hr>

Before I would want to study shaft "stiffness" or "whippy-ness" I would want to know why people think these factors are important. A stiffer shaft usually has more end-mass, which will result in more squirt. It also has a different "feel" due to how the shaft vibrates after a hit. A stiffer shaft might also be stronger and more suitable for a certain style of play.

Do people have other suggestions for why shaft stiffness is important? For example, does anybody think it affects playability (other than squirt)? If you think it affects aspects of "feel," try to describe what you mean.

Regards,
Dave <hr /></blockquote>

I mentioned before that the balance and softer feel of the impact in my hand of a low squirt cue got me back on the table faster after a hand injury

Personally I like the feel of a stick that is lighter in the tip, so they do just feel good in my hand. I also hit very softly (often too softly) so the added ball speed can be a good thing for me

Artemus
12-07-2007, 06:15 AM
<blockquote><font class="small">Quote cushioncrawler:</font><hr> I agree that an axial-impakt-test might be good. For instance we might test the (1) flex (near the tip) , (2) total wt, (3) balance pt, (4) natural vibrational frequency (near the tip), (5) other stuff, but if a cue haz a bad bend then it will lack "power" -- an axial test of some sort might show/measure any lack of power due to (a) a bend, (b) weakness, (c) low wt. madMac. <hr /></blockquote>

You bring up some very good points. Based on your comments, it brings some thoughts to my mind which I haven't the faintest clue as to what I'm talking about or what really happens upon impact with the flex properties.

1. Is there any bend or flex at all near the tip/ferrule, or does it start a number of inches behind that point?

2. How much of an impact force is required to get any bend at all? Let's assume that the maximum CB speed is 35 mph on the fastest break measured by a pro and around 18-20 mph for the average amateur. I'm certain there is shaft bend on both, one more pronounced than the other. However, what amount of flex is there with any and all shafts at regular playing speeds of 1 mph (a mere touch) to about 12-14 mph when you have to run the CB around the table for position?

3. You stated, "if a cue has a bad bend it will lack power". The question in my mind is when does the cue start bending at all and from what CB speeds in mph? I guess Mike Massey can bend a shaft with his force in artistic pool and Larry Nevel with his power draws, but what happens with Joe APAer in normal play? Does an arrow shaft bend upon impact as it enters a deer? Wolfdancer made a comment in his post which holds true for all of us, and that is, why can we have a few shafts made from the same cuemaker, exactly the same weight, tip size, taper, etc., play so differently? Is it flex? If so, how can the shaft be changed to achieve the same frequency?

Keep staying Mad, Max. The more outrageous and "outside the box" the better.

Artemus
12-07-2007, 06:24 AM
<blockquote><font class="small">Quote SKennedy:</font><hr> At my age and experience? Absolutely. Unfortunately, not on this topic. I'll have to recuse myself!
So, what's my severance package? <hr /></blockquote>

I've just been notified by personnel that we have a spot for you that just came available down in the mail room. You're hired! You'll be an independent contractor that's paid based on the number of pieces you handle daily. That means you don't qualify for insurance, vacation pay, sick leave, workman's comp, 401K, pension, or golden parachutes.
You can start tomorrow. /ccboard/images/graemlins/grin.gif

cushioncrawler
12-08-2007, 02:13 AM
<blockquote><font class="small">Quote Artemus:</font><hr> <blockquote><font class="small">Quote cushioncrawler:</font><hr> I agree that an axial-impakt-test might be good. For instance we might test the (1) flex (near the tip) , (2) total wt, (3) balance pt, (4) natural vibrational frequency (near the tip), (5) other stuff, but if a cue haz a bad bend then it will lack "power" -- an axial test of some sort might show/measure any lack of power due to (a) a bend, (b) weakness, (c) low wt.<hr /></blockquote>You bring up some very good points. Based on your comments, it brings some thoughts to my mind which I haven't the faintest clue as to what I'm talking about or what really happens upon impact with the flex properties.
1. Is there any bend or flex at all near the tip/ferrule, or does it start a number of inches behind that point?
2. How much of an impact force is required to get any bend at all? Let's assume that the maximum CB speed is 35 mph on the fastest break measured by a pro and around 18-20 mph for the average amateur. I'm certain there is shaft bend on both, one more pronounced than the other. However, what amount of flex is there with any and all shafts at regular playing speeds of 1 mph (a mere touch) to about 12-14 mph when you have to run the CB around the table for position?
3. You stated, "if a cue has a bad bend it will lack power". The question in my mind is when does the cue start bending at all and from what CB speeds in mph? I guess Mike Massey can bend a shaft with his force in artistic pool and Larry Nevel with his power draws, but what happens with Joe APAer in normal play? Does an arrow shaft bend upon impact as it enters a deer? Wolfdancer made a comment in his post which holds true for all of us, and that is, why can we have a few shafts made from the same cuemaker, exactly the same weight, tip size, taper, etc., play so differently? Is it flex? If so, how can the shaft be changed to achieve the same frequency? Keep staying Mad, Max. The more outrageous and "outside the box" the better.<hr /></blockquote>I reckon that a cue forms an S-bend, especially with center-ball hits. And every bit of the cue bends (or flexes). A cue gets an awefull C-bend if u put a fairly small axial statik load on it -- but an impakt load iz very large and very short term and forms an S-bend (at first).

I reckon that at small speeds the sidewayz "buck" of the qtip iznt great, but nonetheless perhaps the qball can "buck" off-line at a significant angle (what with the qball speed being piddly too). I reckon that every cue haz a natural tendency to buck in one direktion -- hencely u might needta hold the cue the same "way" each shot, or, u might do well to hit the qball with the same bit of the qtip each shot (to help the spin or skrew) -- especially for a bent cue.

I reckon that the major varyable between "identical" cues iz the human one, plus buck direction, plus the "bent-cue" factor (and no cue iz straight), plus the qtip iz critical.

Slo-mo showz that an arrow flexes like mad all the way to the deer -- the deer diminishes the flex.

Woolfy iz aktually a stooge for the defence industry, if u watch u will see him post more and more pictures of beautifull jets fighters the nearer it gets to the election. madMac.

Artemus
12-08-2007, 09:14 AM
So, how do we measure it and be able to compare cue to cue?

You're right about the arrow flexing. I saw something on one of the learning channels of cable tv and they showed slow-mo flight of an arrow and it looks like a snake wiggling and crawling, amazing! The shaft stopped bending upon impact, the opposite of what a cue shaft would do. But the question still is, how much, in what direction it bends, and can it be compared quantitatively or qualitatively to others?
I have still yet seen such a shaft which is referred to as a "wet noodle" or a "buggy whip" either prior to or at impact on the CB.

dr_dave
12-08-2007, 12:33 PM
<blockquote><font class="small">Quote Artemus:</font><hr>You're right about the arrow flexing. I saw something on one of the learning channels of cable tv and they showed slow-mo flight of an arrow and it looks like a snake wiggling and crawling, amazing! The shaft stopped bending upon impact, the opposite of what a cue shaft would do. But the question still is, how much, in what direction it bends, and can it be compared quantitatively or qualitatively to others?
I have still yet seen such a shaft which is referred to as a "wet noodle" or a "buggy whip" either prior to or at impact on the CB.<hr /></blockquote>If you want to see some arrow footage, see the links under "Sports" at high_speed_video.colostate.edu (http://high_speed_video.colostate.edu/)

If you want to see cue response during impact, see HSV 2.1, 4.4, A.5-A.7, A.25 and A.76a here (http://billiards.colostate.edu/high_speed_videos/index.html). HSV A.25 (http://billiards.colostate.edu/high_speed_videos/new/HSVA-25.htm) is probably the closest to what you are hoping to see.

Examples of devices for numerically measuring the impact shock and resulting vibration, along with some example plots, can be found in TP A.9 (http://billiards.colostate.edu/technical_proofs/new/TP_A-9.pdf).

Regards,
Dave

Artemus
12-08-2007, 04:27 PM
Great videos! Thanks for the effort in posting.

Artemus
12-11-2007, 09:33 AM
Dr. Dave,

Would this device work in determining the amount of vibration or flex from one shaft to another to give a numerical assignment to that shaft for across the board comparisons of any or all shafts? Could it also be used by the cuemaker, production cue companies, and after-market shaft manufacturers to determine tighter tolerances based on wood density and taper for flex?

http://billiards.colostate.edu/technical_proofs/new/TP_A-9.pdf

SpiderMan
12-14-2007, 10:51 AM
<blockquote><font class="small">Quote dr_dave:</font><hr> <blockquote><font class="small">Quote Artemus:</font><hr> Dave, I have a new challenge for you and like thinkers regarding the subject of shaft flex. Take a break from squirt, throw, swerve, etc. for a little while.

What kinds of test do you think would be required and specific numbers to determine a somewhat industry accepted standards regarding shaft flex for varying degrees?

I think up until now, a few cuemakers have built a shaft deflection board and attached a weight to the end, but that seems better suited for other sports equipment than a pool shaft.

You hear individuals refer to certain shafts as "whippy" and others as stiff as "rebar". Shouldn't the flex of a pool shaft be measured in a linear fashion based on impact speeds of a known CB weight (6 oz) as opposed to a sideways bending of an attached weight?

Would any so-called "whippy" shaft be very flexible at a slow to medium stroke speed? How hard would you have to hit a ball for it to be whippy and actually see this occurring?

I'd be interested to see if you could come up with something that would greatly impact how shafts are made, perceived, perform, and are bought and sold.

All ideas accepted from everyone in the think tank. <hr /></blockquote>I will add this to my list, but I have several other high-priority items on my list I want to do first (after I finish my series of articles on squirt).

Before I would want to study shaft "stiffness" or "whippy-ness" I would want to know why people think these factors are important. A stiffer shaft usually has more end-mass, which will result in more squirt. It also has a different "feel" due to how the shaft vibrates after a hit. A stiffer shaft might also be stronger and more suitable for a certain style of play.

Do people have other suggestions for why shaft stiffness is important? For example, does anybody think it affects playability (other than squirt)? If you think it affects aspects of "feel," try to describe what you mean.

Regards,
Dave <hr /></blockquote>

I don't have an immediate opinion about the application/usefulness of flexibility data, but I guess I disagree with the various suggestions of measuring it with an impact test. A test of that nature would not isolate the "flexibility variable" - the results would be colored by effective end mass.

Pure "flexibility" would be best measured in a static test. I believe a static test is what was originally used by Meucci as their method for putting the "dots" on their shafts. I once examined a rack of Meucci "dot" shafts, and noted that the dots were always placed on a cross-grain, never a broadside-grain, location. As far as I could tell, Meucci could have skipped any testing and just put the dots on by visual means.

SpiderMan

dr_dave
12-14-2007, 12:04 PM
<blockquote><font class="small">Quote SpiderMan:</font><hr>I don't have an immediate opinion about the application/usefulness of flexibility data, but I guess I disagree with the various suggestions of measuring it with an impact test. A test of that nature would not isolate the "flexibility variable" - the results would be colored by effective end mass.

Pure "flexibility" would be best measured in a static test. I believe a static test is what was originally used by Meucci as their method for putting the "dots" on their shafts. I once examined a rack of Meucci "dot" shafts, and noted that the dots were always placed on a cross-grain, never a broadside-grain, location. As far as I could tell, Meucci could have skipped any testing and just put the dots on by visual means.<hr /></blockquote>Spiderman,

It's good to see you posting again. What's the latest report on your recovery?

Here's a photo (http://www.budgetcues.com/images/meucci/meucci%20black%20dot%20chart.jpg) with the "dot" as you you describe (I think). I just checked a "Black dot" shaft, and the dot is about 60-70 degrees away from what the picture shows, but I don't know how common this is. Personally, I don't think it matters where the "dot" is placed (until I see hard data to convince me otherwise).

I do know that when I tested the "Black dot" shaft in my squirt-test machine at different orientations (cue twist positions), the squirt was fairly consistent at all orientations (no orientation-dependent trends were obvious). The results will appear in my February '08 BD article (http://billiards.colostate.edu/bd_articles/index.html). I would share the results here, but I don't want to get into trouble again.

I also just did a crude static flex test. I had the shaft hanging over the edge of a flat table and I hung a fairly heavy C-clamp to the end of the shaft. With the dot up, the tip deflected about 29 mm, and with the dot turned 90 degrees, the shaft deflected about 28 mm. So the lateral stiffness does not seem to change very much with orientation.

Regards,
Dave

Artemus
12-14-2007, 12:14 PM
The red or black dot was to locate the spine as far as I understand it, not the amount of flexibility that could be compared to one shaft or another whether Meucci or all shafts.

Dr. Dave, you never answered my post about the device you referred to on your website. Don't you like me? /ccboard/images/graemlins/confused.gif

dr_dave
12-14-2007, 12:29 PM
<blockquote><font class="small">Quote Artemus:</font><hr> The red or black dot was to locate the spine as far as I understand it, not the amount of flexibility that could be compared to one shaft or another whether Meucci or all shafts.<hr /></blockquote>How is the "spine" defined, and what physical property differences would you expect in the spine direction?

<blockquote><font class="small">Quote Artemus:</font><hr>Dr. Dave, you never answered my post about the device you referred to on your website.<hr /></blockquote>Sorry about that. If you provide a link to your question, or ask it again, I would be happy to try to answer.

<blockquote><font class="small">Quote Artemus:</font><hr>Don't you like me? /ccboard/images/graemlins/confused.gif <hr /></blockquote>I don't know. I haven't met you. I've learned to try to not judge people based solely on Internet postings.

Regards,
Dave

Artemus
12-14-2007, 01:20 PM
<blockquote><font class="small">Quote dr_dave:</font><hr> <blockquote><font class="small">Quote Artemus:</font><hr> The red or black dot was to locate the spine as far as I understand it, not the amount of flexibility that could be compared to one shaft or another whether Meucci or all shafts.<hr /></blockquote>How is the "spine" defined, and what physical property differences would you expect in the spine direction?

<font color="red"> http://www.ravencues.com/spine.html </font color>

<font color="red"> Spine is also mentioned here: http://www.meuccicues.com/reddot.htm </font color>

<blockquote><font class="small">Quote Artemus:</font><hr>Dr. Dave, you never answered my post about the device you referred to on your website.<hr /></blockquote>Sorry about that. If you provide a link to your question, or ask it again, I would be happy to try to answer.
Regards,
Dave <hr /></blockquote>

The post that I was referring to is the one immediately preceeding Spiderman's. (3 posts ago)

Mention of the spine is on this link to Meucci under the Black Dot shaft picture. You might also be interested in how he built, setup his robot, and conducted his deflection tests.

http://www.meuccicues.com/BlackDot.htm

SpiderMan
12-14-2007, 01:44 PM
<blockquote><font class="small">Quote dr_dave:</font><hr> <blockquote><font class="small">Quote SpiderMan:</font><hr>I don't have an immediate opinion about the application/usefulness of flexibility data, but I guess I disagree with the various suggestions of measuring it with an impact test. A test of that nature would not isolate the "flexibility variable" - the results would be colored by effective end mass.

Pure "flexibility" would be best measured in a static test. I believe a static test is what was originally used by Meucci as their method for putting the "dots" on their shafts. I once examined a rack of Meucci "dot" shafts, and noted that the dots were always placed on a cross-grain, never a broadside-grain, location. As far as I could tell, Meucci could have skipped any testing and just put the dots on by visual means.<hr /></blockquote>Spiderman,

It's good to see you posting again. What's the latest report on your recovery?

Here's a photo (http://www.budgetcues.com/images/meucci/meucci%20black%20dot%20chart.jpg) with the "dot" as you you describe (I think). I just checked a "Black dot" shaft, and the dot is about 60-70 degrees away from what the picture shows, but I don't know how common this is. Personally, I don't think it matters where the "dot" is placed (until I see hard data to convince me otherwise).

I do know that when I tested the "Black dot" shaft in my squirt-test machine at different orientations (cue twist positions), the squirt was fairly consistent at all orientations (no orientation-dependent trends were obvious). The results will appear in my February '08 BD article (http://billiards.colostate.edu/bd_articles/index.html). I would share the results here, but I don't want to get into trouble again.

I also just did a crude static flex test. I had the shaft hanging over the edge of a flat table and I hung a fairly heavy C-clamp to the end of the shaft. With the dot up, the tip deflected about 29 mm, and with the dot turned 90 degrees, the shaft deflected about 28 mm. So the lateral stiffness does not seem to change very much with orientation.

Regards,
Dave <hr /></blockquote>

Because it is a laminate, perhaps the black-dot shaft exhibits less directionality than one made of natural wood. That would certainly be the case if the sections were somewhat randomly cut and the glue not a significant factor. Perhaps the blacks started out similar to the reds, but then some change in manufacturing or materials caused the "spine" to become more homogenous. That was a very interesting measurement.

Regarding recovery - I've been off the crutches for 3 weeks now, and am doing some physical therapy for the shoulder. Rad report says torn rotator cuff, torn labrum, and torn something else (can't remember at the moment). Hopefully PT doesn't tear it worse. Got my hand out of the cast two weeks ago, but something is still wrong with the middle joint of my right index finger. I can't straighten it or bend it beyond 90 degrees, and it swells up when I try. I'll probably retain a pretty large hemispherical mound on my shin forever, but at least it's not on my face /ccboard/images/graemlins/smile.gif I have a little bit of nerve damage also, as I have no sensation in the skin of my upper left arm or lower left leg. But the size of the numb areas seems to be reducing a little. Oh, and I bought a new motorcycle, but it's a Harley this time so I guess I better get my legs built up for pushing. Hopefully it won't pee oil on my garage floor.

SpiderMan

dr_dave
12-14-2007, 03:08 PM
<blockquote><font class="small">Quote Artemus:</font><hr>http://billiards.colostate.edu/technical_proofs/new/TP_A-9.pdf

Dr. Dave,

Would this device work in determining the amount of vibration or flex from one shaft to another to give a numerical assignment to that shaft for across the board comparisons of any or all shafts?<hr /></blockquote>Accelerometers do measure vibration very accurately, and much information can be derived from vibration data (e.g., stiffnesses, damping characteristics, sound, "feel," etc.). So I guess my answer is yes (with appropriate analysis).

<blockquote><font class="small">Quote Artemus:</font><hr>Could it also be used by the cuemaker, production cue companies, and after-market shaft manufacturers to determine tighter tolerances based on wood density and taper for flex?<hr /></blockquote>I think accelerometers can be used to help characterize and compare cues, but I'm not sure how the cue industry (or cue customers) would use this information, and if they would want to pay for it. I think when it comes to selling cues, marketing hype can be much more effective than scientific data.

Regards,
Dave

dr_dave
12-14-2007, 03:20 PM
<blockquote><font class="small">Quote Artemus:</font><hr> The red or black dot was to locate the spine as far as I understand it, not the amount of flexibility that could be compared to one shaft or another whether Meucci or all shafts. <blockquote><font class="small">Quote dr_dave:</font><hr> How is the "spine" defined, and what physical property differences would you expect in the spine direction?<hr /></blockquote>
<font color="red">http://www.ravencues.com/spine.html</font color>

<font color="red"> Spine is also mentioned here: http://www.meuccicues.com/reddot.htm</font color><hr /></blockquote>Thanks for the links. So it seems most people use "spine" to refer to the shaft orientation with the greatest stiffness.

<blockquote><font class="small">Quote Artemus:</font><hr>Dr. Dave, you never answered my post about the device you referred to on your website.<blockquote><font class="small">Quote dr_dave:</font><hr>Sorry about that. If you provide a link to your question, or ask it again, I would be happy to try to answer.<hr /></blockquote>The post that I was referring to is the one immediately preceeding Spiderman's. (3 posts ago)<hr /></blockquote>Sorry, I didn't see it. Sometimes the forum software fails to properly indicate which posts have been read or not. I just replied.

<blockquote><font class="small">Quote Artemus:</font><hr>Mention of the spine is on this link to Meucci under the Black Dot shaft picture. You might also be interested in how he built, setup his robot, and conducted his deflection tests.

http://www.meuccicues.com/BlackDot.htm
<hr /></blockquote>Thanks for the link. I am well aware of the "Myth Destroyer" machine. I've had a link to Meucci squirt-comparison video on my website for a long time.

Regards,
Dave

dr_dave
12-14-2007, 03:25 PM
<blockquote><font class="small">Quote SpiderMan:</font><hr>Regarding recovery - I've been off the crutches for 3 weeks now, and am doing some physical therapy for the shoulder. Rad report says torn rotator cuff, torn labrum, and torn something else (can't remember at the moment). Hopefully PT doesn't tear it worse. Got my hand out of the cast two weeks ago, but something is still wrong with the middle joint of my right index finger. I can't straighten it or bend it beyond 90 degrees, and it swells up when I try. I'll probably retain a pretty large hemispherical mound on my shin forever, but at least it's not on my face /ccboard/images/graemlins/smile.gif I have a little bit of nerve damage also, as I have no sensation in the skin of my upper left arm or lower left leg. But the size of the numb areas seems to be reducing a little. Oh, and I bought a new motorcycle, but it's a Harley this time so I guess I better get my legs built up for pushing. Hopefully it won't pee oil on my garage floor.<hr /></blockquote>It sounds like a mix of good and bad news. I hope the Holiday Season brings you more on the good side rather than the bad.

Regards,
Dave

dr_dave
12-14-2007, 03:38 PM
<blockquote><font class="small">Quote SpiderMan:</font><hr>Because it is a laminate, perhaps the black-dot shaft exhibits less directionality than one made of natural wood. That would certainly be the case if the sections were somewhat randomly cut and the glue not a significant factor. Perhaps the blacks started out similar to the reds, but then some change in manufacturing or materials caused the "spine" to become more homogenous. That was a very interesting measurement.<hr /></blockquote>But isn't the whole point of the "dot" to help you orient the cue so you get the same "directional properties" for every shot? /ccboard/images/graemlins/crazy.gif

I look forward to trying out the static stiffness test and the machine-squirt-measurement tests on several types of cues in various orientations.

Regards,
Dave

SpiderMan
12-14-2007, 03:44 PM
<blockquote><font class="small">Quote dr_dave:</font><hr> <blockquote><font class="small">Quote SpiderMan:</font><hr>Because it is a laminate, perhaps the black-dot shaft exhibits less directionality than one made of natural wood. That would certainly be the case if the sections were somewhat randomly cut and the glue not a significant factor. Perhaps the blacks started out similar to the reds, but then some change in manufacturing or materials caused the "spine" to become more homogenous. That was a very interesting measurement.<hr /></blockquote>But isn't the whole point of the "dot" to help you orient the cue so you get the same "directional properties" for every shot? /ccboard/images/graemlins/crazy.gif

Regards,
Dave <hr /></blockquote>

Yes, but if the shaft does not exhibit directional properties, aligning the dot will do no harm, and it's still good marketing to put it on. If the dot placement is machine-determined by measurement, and the shaft is radially consistent, then I'd expect the dot to move around from batch to batch.

SpiderMan

Deeman3
12-14-2007, 04:45 PM
This may be silly as I don't normally worry about things as complex as radial shaft orientation but:

Other than center ball hits, would the orientation not need to be "adjusted" around the center axis of the shaft to accomodate for english, follow and draw. In other words, would you need to turn the shaft 90 degress clockwise for a 3:00 o'clock shot to gain consistent result for that orientation and CCW 120 for low left, for instance? Otherwise you would be just learning to hit around the different flaws of the shaft. (Or perhaps that is the intent here) I have a couple of black dots that came with some of those Meucci's someone dumped in my car and perhaps even a red dot one or two but never bothered to check which way they were migrating when shooting.

I saw Bob at Valley Forge a few years ago with his machine but was too busy eating a Phily Steak and Cheese to watch him play with it. /ccboard/images/graemlins/shocked.gif

dr_dave
12-14-2007, 04:53 PM
I'm with you on this one, so I guess I might be silly too.

I don't think the shaft orientation makes much difference; but if it did, I agree with you that you would want a different orientation for every tip "clock" position on the cue ball.

Regards,
Dave

<blockquote><font class="small">Quote Deeman3:</font><hr> This may be silly as I don't normally worry about things as complex as radial shaft orientation but:

Other than center ball hits, would the orientation not need to be "adjusted" around the center axis of the shaft to accomodate for english, follow and draw. In other words, would you need to turn the shaft 90 degress clockwise for a 3:00 o'clock shot to gain consistent result for that orientation and CCW 120 for low left, for instance? Otherwise you would be just learning to hit around the different flaws of the shaft. (Or perhaps that is the intent here) I have a couple of black dots that came with some of those Meucci's someone dumped in my car and perhaps even a red dot one or two but never bothered to check which way they were migrating when shooting.

I saw Bob at Valley Forge a few years ago with his machine but was too busy eating a Phily Steak and Cheese to watch him play with it. /ccboard/images/graemlins/shocked.gif <hr /></blockquote>

Artemus
12-14-2007, 05:42 PM
<blockquote><font class="small">Quote dr_dave:</font><hr> <blockquote><font class="small">Quote Artemus:</font><hr>http://billiards.colostate.edu/technical_proofs/new/TP_A-9.pdf

Dr. Dave,

Would this device work in determining the amount of vibration or flex from one shaft to another to give a numerical assignment to that shaft for across the board comparisons of any or all shafts?<hr /></blockquote>Accelerometers do measure vibration very accurately, and much information can be derived from vibration data (e.g., stiffnesses, damping characteristics, sound, "feel," etc.). So I guess my answer is yes (with appropriate analysis).

<blockquote><font class="small">Quote Artemus:</font><hr>Could it also be used by the cuemaker, production cue companies, and after-market shaft manufacturers to determine tighter tolerances based on wood density and taper for flex?<hr /></blockquote>I think accelerometers can be used to help characterize and compare cues, but I'm not sure how the cue industry (or cue customers) would use this information, and if they would want to pay for it. I think when it comes to selling cues, marketing hype can be much more effective than scientific data.

<font color="red"> I agree about the marketing hype, but it would add multiple bullets to their arsenal to sell more cues. Here's why I think it's desired information.

You science guys get off on using your educational and work backgrounds to play with equations, theories, laws of physics etc., as far as how balls roll and interact upon impact as well as the deflection of both cue and CB, friction, Coriolis force and all the rest. The only thing I haven't heard yet is how negative ions and electromagnetic charges in the air from a major storm affects shots while playing in a storm. For some guys it's beneficial and educational, but many could care less and especially when a certain POS poster goes into his megalomaniacal act of being the forum king of intellectuals in pool. (not here) Personally I appreciate what you've done and have written.

But if you go on ANY forum, the regular posters luuuuuvvvvv
talking about cues and the "HIT". What makes a cue FEEL good? What makes a cue HIT good? What makes a cue PERFORM? And inevitably someone will always bring up the flex of the shaft. "It plays stiff", "It plays too stiff"
"It's not stiff enough", "It's like a wet noodle", "It's like a buggy whip", "I felt it flexing all over the place",
and it just goes on.

You also have many cue collectors or guys that buy cues and want to match shafts that play exactly the same. On the other hand, they might want shafts that play a little differently.

Does flex affect accuracy? Does flex affect the hit? Does flex affect the english or draw? How would one know if they have no clue what the flex actually is and where to start testing? I could easily paste and copy thousands of posts from guys on this subject, but I'm not THAT ambitious and care to waste my time. </font color>

Regards,
Dave <hr /></blockquote>

dr_dave
12-14-2007, 05:59 PM
<blockquote><font class="small">Quote Artemus:</font><hr>But if you go on ANY forum, the regular posters luuuuuvvvvv
talking about cues and the "HIT". What makes a cue FEEL good? What makes a cue HIT good? What makes a cue PERFORM? And inevitably someone will always bring up the flex of the shaft. "It plays stiff", "It plays too stiff"
"It's not stiff enough", "It's like a wet noodle", "It's like a buggy whip", "I felt it flexing all over the place",
and it just goes on.<hr /></blockquote>Like you, I would like to be able to quantify some of these things, but first I need to better understand what people really mean when they say things like "hit," "feel," "stiff," "whippy," "playability," and "performance." I also need to know why one person can say a cue "feels whippy and hits bad" and another person can say the opposite about the exact same cue ("it is stiff and hits great"). I would like to hear from others about what some of these "descriptors" really mean in a physical sense. I am also very curious about which attributes are determined mostly by the tip and which are determined mostly by the shaft, joint, and/or butt. I will also try to talk to some people I know who know a lot about cues so I can try to get some answers.

Regards,
Dave

Artemus
12-14-2007, 07:19 PM
<blockquote><font class="small">Quote dr_dave:</font><hr> <blockquote><font class="small">Quote Artemus:</font><hr>But if you go on ANY forum, the regular posters luuuuuvvvvv
talking about cues and the "HIT". What makes a cue FEEL good? What makes a cue HIT good? What makes a cue PERFORM? And inevitably someone will always bring up the flex of the shaft. "It plays stiff", "It plays too stiff"
"It's not stiff enough", "It's like a wet noodle", "It's like a buggy whip", "I felt it flexing all over the place",
and it just goes on.<hr /></blockquote>Like you, I would like to be able to quantify some of these things, but first I need to better understand what people really mean when they say things like "hit," "feel," "stiff," "whippy," "playability," and "performance." I also need to know why one person can say a cue "feels whippy and hits bad" and another person can say the opposite about the exact same cue ("it is stiff and hits great").

<font color="red"> So would I! I think many of them say it becasue they're followers of the crowd and what others have stated. Everybody wants to be a member in good standing and a part of something. That's why I don't know what comes first, THEIR definitions and descriptions or actual tests that can quantitatively illustrate or refute the facts. I certainly haven't seen anyone state anything off the wall about deflection in specific cues now that Platinum Billiards has their test results on everything. </font color>

I would like to hear from others about what some of these "descriptors" really mean in a physical sense. I am also very curious about which attributes are determined mostly by the tip and which are determined mostly by the shaft, joint, and/or butt.

<font color="red"> Good luck on that one, LOL. There will never be enough agreement in any particular area to make a logical decision. </font color>
I will also try to talk to some people I know who know a lot about cues so I can try to get some answers.

Regards,
Dave <hr /></blockquote>

I am glad your curiosity is raised. /ccboard/images/graemlins/wink.gif

Artemus
12-15-2007, 06:19 AM
<blockquote><font class="small">Quote dr_dave:</font><hr> I'm with you on this one, so I guess I might be silly too.

I don't think the shaft orientation makes much difference; but if it did, I agree with you that you would want a different orientation for every tip "clock" position on the cue ball.

Regards,
Dave
<hr /></blockquote>

I don't know if shaft orientation and the spine makes any difference on a pool cue either. Bob Meucci seems to think so as do a number of other cuemakers.

I did happen to stumble upon this video demonstration regarding the spine of a golf shaft and how the spine orientation definitely affects how the head reacts to squaring itself at impact with the golf ball. It's very convincing for a golf shaft.

Click onto these video demonstrations:

http://toky.it/video/watch.asp?v=agcp