First cue-testing robot?

AtLarge

AzB Gold Member
Gold Member
Silver Member
Anyone know when The Myth Destroyer was introduced? (I may eventually find a Meucci ad that mentions it, but I haven't so far.)

The Blue Book of Pool Cues, 3rd Edition says: "In 1998, Bob built the 'Myth Destroyer,' a robot to test deflection in cues."
 
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Patrick Johnson

Fish of the Day
Silver Member
So many people believe that changing the velocity is more important than changing the weight. But that's not true in the pool stroke model. The energy that the player brings to the stroke is everything. That's the input. Velocity is the result.
I respect your physics/mechanics expertise, but still don't get your point.

Yes, it takes more energy to move a stick with more velocity (or a heavier stick the same velocity), but that doesn't negate the importance to momentum/kinetic energy of velocity over weight. Nobody's saying (that I've seen) the same energy input can produce more energy output - in fact, I've said the opposite more than once (in other threads).

To put it another way, if the four factors are muscle power (stroke), stick weight, stick speed and CB speed, you're talking about all four and I was only talking about the last three.

Sorry if my layman terminology confuses things.

pj
chgo
 
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The_JV

'AZB_Combat Certified'
Velocity is an output, not an input.

If I managed to follow along correctly, I agree...lol

In terms of the player swinging the cue. Velocity is indeed the result of the energy applied to the mass of the cue. Lower the mass, maintain the energy, the end result (velocity) is greater.

The portion of the break I tend to focus on, is the transfer of energy to the cue ball from the cue. This requires velocity. Infinite kinetic energy at near zero velocity imparts near zero velocity to the cue ball. We could add coil/spring action of the compressing cue tip or whatever if we would like to complicate it further, but generally speaking you cannot generate greater velocity on the cue ball than what the cue spd was.

Additional pool cue mass (kinetic energy) only matters if the player stops applying energy to the forward motion of the cue at the moment of contact. However that is never the case, and I'd wager that nearly all additional losses the lighter cue suffers from the lesser amount of kinetic energy are compensated for by the continued motion (energy) of the player.

I respect your physics/mechanics expertise,

Ok cool.... I'm assuming your comment means he has some higher education working for him. Based on his posts, I figured he had to be someone with a severely greater knowledge of physics then myself....
 
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Patrick Johnson

Fish of the Day
Silver Member
Lower the mass, maintain the energy, the end result (velocity) is greater.
Equal muscle power = equal CB velocity no matter the mass. But equal cue speed = less CB velocity with a lighter cue and greater CB velocity with a heavier cue.

Additional pool cue mass (kinetic energy) only matters if the player stops applying energy to the forward motion of the cue at the moment of contact.
Sounds like you're saying the player's hand continues to push the cue through the CB after contact. That's not the case because the soft flesh of the hand allows the cue to virtually stop on contact (even with a tight grip), and the flesh doesn't "recover" in time to push the stick again until after the CB is gone.

pj
chgo
 
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Cornerman

Cue Author...Sometimes
Gold Member
Silver Member
Nobody's saying (that I've seen) the same energy input can produce more energy output - in fact, I've said the opposite more than once (in other threads).

I'm sure you and I are aligned, but what I initially said in this thread is that saying things like "increasing the speed is more important" is misleading. Thousands of internet readers currently believe that a "lighter cue is more advantageous than a heavier cue because you can get a lighter cue to a higher velocity... because increasing the speed is more important."

That's what I'm saying. Physics-wise, a lighter cue and its resultant "higher stick speed" is not inherently more advantageous. But lots of forum readers will swear by it because they misunderstood the "velocity squared" concept, and they'll cite the kinematic equation is proof.
 

Cornerman

Cue Author...Sometimes
Gold Member
Silver Member
The portion of the break I tend to focus on, is the transfer of energy to the cue ball from the cue. This requires velocity.
and mass. The basic transfer of motion is the momentum change of both stick and ball. Mass x velocity. We could examine energy transfer, but then we'd have to look at heat and sound as part of the energy transferred. Momentum will do just fine. The cueball will go faster than the cue stick... about 1 1/2 times (not including losses).



Ok cool.... I'm assuming your comment means he has some higher education working for him. Based on his posts, I figured he had to be someone with a severely greater knowledge of physics then myself....
LOL. I started reading billiard internet forums (1995) shortly after getting my degree. If it weren't for internet forums and pool in general, I would have forgotten a long time ago what happened if a ice skater on a frozen pond runs into a stationary elephant with mud on its ass. I'd have almost no reason to think about collision physics or wave theory. I do a small amount of mechanical acoustic frequency, but it's a very small part of my career.
 

MitchAlsup

AzB Silver Member
Silver Member
When Allan McCarty designed their first break cue...he shipped me an early one...
BK First Edition
..we were on the phone for a while....something that amazed him...he said..
“When I started to design the break cue, I was sure it would have a stainless steel joint...
...but Iron Willie showed us that the speed of the cue ball coming off the tip was 7 to 12 %
quicker with a wood to wood joint.”....I told him that explains why I never found a snooker
cue with a metal joint that I liked...in snooker you need that extra power,

I enjoyed this thought.......BUT

Since the shock wave from making contact (0 ms) with the CB does not arrive at the joint by the time the CB has left (1-2 ms) the tip and is traveling faster than the cue, the joint plays no part in the velocity of the CB other than the mass it adds in the middle of the cue.

Did the W-W joint end up causing the cue to weigh less ?
 

Patrick Johnson

Fish of the Day
Silver Member
I'm sure you and I are aligned, but what I initially said in this thread is that saying things like "increasing the speed is more important" is misleading. Thousands of internet readers currently believe that a "lighter cue is more advantageous than a heavier cue because you can get a lighter cue to a higher velocity... because increasing the speed is more important."

That's what I'm saying. Physics-wise, a lighter cue and its resultant "higher stick speed" is not inherently more advantageous. But lots of forum readers will swear by it because they misunderstood the "velocity squared" concept, and they'll cite the kinematic equation is proof.
Gotcha now, and agree. Thanks, Freddie.

pj
chgo
 

Patrick Johnson

Fish of the Day
Silver Member
...the shock wave from making contact (0 ms) with the CB does not arrive at the joint by the time the CB has left (1-2 ms) the tip
You used this fact before to say that an increase in overall stick mass is pretty much irrelevant - I'm guessing that's based on the assumption that an increase in overall stick mass will be concentrated mostly in the butt half?

I'm thinking (but not sure) that the mass increases by the same percentage in the butt and shaft, so if the overall mass increases by 1/9 (2 oz. increase for an 18 oz cue), then the kinetic energy into the CB increases by 1/9 too, regardless of how much of the cue is "involved".

Welcome any correction...

pj
chgo
 

iusedtoberich

AzB Silver Member
Silver Member
I’d think someone came up with a cue stick robot well before Predator or Meucci. Maybe Brunswick did 100 years ago.
 

Cornerman

Cue Author...Sometimes
Gold Member
Silver Member
This is not just a physics question. It also depends on the person's muscle physiology and anatomy.

No doubt. I'd love to say "all other things being equal,.." but how a person and their physiology interact with the cue is paramount.

This brings up uber memories. The first time I even answered the "is a light stick better for breaking," I was still in college. 1988 or so, I sent a letter to Billiards Digest trying to explain why "lighter isn't inherently better," all other things being equal, and that how a person breaks is more important than anything.

It's all the same, after all these years.
 

Bob Jewett

AZB Osmium Member
Staff member
Gold Member
Silver Member
I’d think someone came up with a cue stick robot well before Predator or Meucci. Maybe Brunswick did 100 years ago.
The earliest ball-hitting apparatus I know of that could be used to get measurements was built by A.D. Moore about 1940. It was a cue suspended from strings and could be swung to hit a ball with a known speed. (The speed was known from the height the cue as swung from.) Moore was an engineering professor.

Moore used that apparatus to measure the efficiency of tip-ball contact. He got something like the cue ball moving at 130% of the stick speed when about 150% was expected for a collision that did not lose energy.
 

pt109

WO double hemlock
Silver Member
Then what about a one piece? Or are you saying any cue will deliver a 58" wave as well as all the harmonics?

At the risk of answering a question that I might not understand what you're asking, there is a compression wave (due to the axial force) and a transverse wave (if it has a lateral force, of course). The transverse wave is used (can be used) to model the squirt characteristics.

Freddie <~~~ acoustically speaking

This is a bit of an aside....I want through about 5,000 one piece cues one summer in the 80s,
Those were used cues, the older the better.

I was looking for a snooker cue of the quality of my playing cue...I failed...they didn’t get
the consideration in the building...time, quality wood, and expertise. If a great cue maker
made some on piece cues, I would’ve bought some.
So a house cue is not a fair test,
 

pt109

WO double hemlock
Silver Member
The Blue Book of Pool Cues, 3rd Edition says: "In 1998, Bob built the 'Myth Destroyer,' a robot to test deflection in cues."

I was asked to be an observer in ‘89 at a trade show for a ‘deflectionless’ demonstration.
Cue ball 8 inches off the end rail...object ball froze on the other end rail..straight on.
The player aimed straight at the ball with maximum right english...he hit the ball almost
perfectly full...that was the Meucci proof that their cue was deflectionless.
My friend was impressed, but I told him privately that there was no such thing as a
deflectionless cue, If you change the speed or distance, it would go elsewhere...
...even a different cloth would alter the results.
You could only make a cue more ‘user friendly’ than a 13 mm ivory ferrule.
 

Patrick Johnson

Fish of the Day
Silver Member
The player aimed straight at the ball with maximum right english...he hit the ball almost
perfectly full...that was the Meucci proof that their cue was deflectionless.
Of course it probably just showed that swerve happens...

pj
chgo
 

MooseKnuckle

Registered
Sorry for the golf interruption, Iron Byron was what first came to mind, invented in the 60's I think.

God Speed Byron Nelson

*edit : from the golf swing analysis -

Physiologists and sports consultants have found that instant tactile feedback for the desired bodily movement greatly speeds up the gaining of the new habit or new muscle memory or new movement. The brain utilizes the kinesthetic learning of tactile feedback to help develop the new muscle memory.

Carry on, back to the pool debate :)
 
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