Cue stroking machines

S

slach

AzB Silver Member
Silver Member
Been seeing more posts lately about cue shaft deflection and ratings by AZ members comparing various shafts, particularly the new carbon fiber ones. It's all interesting and probably accurate but it still seems pretty subjective, relying mostly on a human being able to exactly duplicate a stroke and observing the amount the cue ball squirts.

I've seen some older posts about cue stroking machines (for sure Meucci had one and I think Predator as well) attempting to quantify deflection. But these machines don't seem to be accepted as giving true measures of a cue's performance. Why not? I'd think that since accuracy is so important in pool a machine would be perfect to put to rest all the competing claims about which shafts have lower deflection, which chalk/tip gives more spin, which cue imparts more 'energy', and so on. What's the problem with stroke machines? Why isn't there a standard machine? What would the perfect machine need to be to become the standard?

I'm not saying that deflection is good or bad, you of course need to know your cue and adjust accordingly when using english. But it'd be great to know what you're really getting before you invest in a new cue.
 
Bob Jewett

Bob Jewett

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slach said:
...
I've seen some older posts about cue stroking machines (for sure Meucci had one and I think Predator as well) attempting to quantify deflection. But these machines don't seem to be accepted as giving true measures of a cue's performance. Why not? ...
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The problems with pool-shooting robots (Meucci's Myth Destroyer and Predator's Iron Willie III?) have been discussed recently in another thread. I don't have a link handy but it should be easy to find.

Predator has made several improvements to Willie since the version I saw in 1998. It now handles the cue stick more like a human.

There are some people who do feel that the results from well-designed robots are useful. Others may feel that you can't make any cue test objective.
 
M

MitchAlsup

AzB Silver Member
Silver Member
slach said:
But these machines don't seem to be accepted as giving true measures of a cue's performance. Why not?
Click to expand...

Because they do not provide repeatable data.

If you set up a difficult shot {spin, deflection, speed, rails} a precise machine could land the CB on a dime every single time.

The currently known testing machines don't have this kind of precision.
 
Patrick Johnson

Patrick Johnson

Fish of the Day
Silver Member
slach said:
What's the problem with stroke machines? Why isn't there a standard machine?
Click to expand...

MitchAlsup said:
Because they do not provide repeatable data.

If you set up a difficult shot {spin, deflection, speed, rails} a precise machine could land the CB on a dime every single time.

The currently known testing machines don't have this kind of precision.
Click to expand...
I'll bet Dr. Dave's machine is pretty good. Wonder where we could see it...

pj
chgo
 
H

heater451

Registered
MitchAlsup said:
Because they do not provide repeatable data.

If you set up a difficult shot {spin, deflection, speed, rails} a precise machine could land the CB on a dime every single time.

The currently known testing machines don't have this kind of precision.
Click to expand...

I bet the machines are accurate enough now, but for any side-spin setup, I think it would be very difficult to ensure that the cue ball was set up exactly the same, every time, even with some type of jig. Still, increasing the volume of times the "same" shot is attempted, should eventually create enough numbers that the averages could be used to determine whatever it is one was researching.

I would think that most results would exhibit close to a standard bell curve, and of course, the more numbers to plot, the better the average is.

For example, if you set up a 30-deg cut, long table, to the left corner, and were attempting to land in a circle of 3 inches diameter, the more times a robot made the shot, the more times it is likely to get it right. Again, the cue ball and object ball would both have to be in the *exact* same starting positions. The set-up is hard to duplicate, considering how little variation can affect the results, but when an off-center (sidespin) shot it being set up, I would think it MUCH harder to repeat.
 
dr_dave

dr_dave

Instructional Author
Gold Member
Silver Member
slach said:
Been seeing more posts lately about cue shaft deflection and ratings by AZ members comparing various shafts, particularly the new carbon fiber ones. It's all interesting and probably accurate but it still seems pretty subjective, relying mostly on a human being able to exactly duplicate a stroke and observing the amount the cue ball squirts.

I've seen some older posts about cue stroking machines (for sure Meucci had one and I think Predator as well) attempting to quantify deflection. But these machines don't seem to be accepted as giving true measures of a cue's performance. Why not? I'd think that since accuracy is so important in pool a machine would be perfect to put to rest all the competing claims about which shafts have lower deflection, which chalk/tip gives more spin, which cue imparts more 'energy', and so on. What's the problem with stroke machines? Why isn't there a standard machine? What would the perfect machine need to be to become the standard?

I'm not saying that deflection is good or bad, you of course need to know your cue and adjust accordingly when using english. But it'd be great to know what you're really getting before you invest in a new cue.
Click to expand...
FYI, a lot of info dealing with this topic can be found here:

robot cue testing machines

I like your idea of a standard affordable machine that would be used widely. Hopefully, that will happen some day.

Enjoy,
Dave
 
dr_dave

dr_dave

Instructional Author
Gold Member
Silver Member
Patrick Johnson said:
I'll bet Dr. Dave's machine is pretty good. Wonder where we could see it...
Click to expand...
The machine I develop at Colorado State University (with the help of some students) was for a sponsor (CueStix) who didn't want others to see it. I'm not sure if they still use it or not, and I haven't seen it in many years.

In the past, I had the idea of developing a new machine based on everything we learned, and then create an "independent" cue testing laboratory that all cues could be sent to for official testing and data publishing. I no longer have the desire to do such a thing, but I hope somebody does this some day. It would be helpful if every cue sold came with some useful performance data like natural pivot length, hit efficiency, impact and vibration characteristics, etc. Then educated decisions could be made when you purchase a new cue. I know ... now I'm really dreaming. :rolleyes:

A lot of what we learned can be found on the squirt robot testing resource page (for the benefit of whoever might take this project on in the future).

Regards,
Dave
 
S

slach

AzB Silver Member
Silver Member
dr_dave said:
The machine I develop at Colorado State University (with the help of some students) was for a sponsor (CueStix) who didn't want others to see it. I'm not sure if they still use it or not, and I haven't seen it in many years.

In the past, I had the idea of developing a new machine based on everything we learned, and then create an "independent" cue testing laboratory that all cues could be sent to for official testing and data publishing. I no longer have the desire to do such a thing, but I hope somebody does this some day. It would be helpful if every cue sold came with some useful performance data like natural pivot length, hit efficiency, impact and vibration characteristics, etc. Then educated decisions could be made when you purchase a new cue. I know ... now I'm really dreaming. :rolleyes:

A lot of what we learned can be found on the squirt robot testing resource page (for the benefit of whoever might take this project on in the future).

Regards,
Dave
Click to expand...

Dr Dave, any particular reason(s) you lost interest in creating an independent testing lab? It's pretty common in golf, though the independence part is a little questionable (or the JD Powers auto awards where every model seems to win something).
 
Bob Jewett

Bob Jewett

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heater451 said:
... I think it would be very difficult to ensure that the cue ball was set up exactly the same, every time, even with some type of jig. ...
Click to expand...
As I recall, Iron Willie used a metal V that the cue ball rested against. The V was part of the bridge structure. I think the cue ball position was repeatable within a few thousandths of an inch relative to the tip -- like the thickness of printer paper. It would be interesting to see how that sort of accuracy compares to a top human player.
 
dr_dave

dr_dave

Instructional Author
Gold Member
Silver Member
slach said:
Dr Dave, any particular reason(s) you lost interest in creating an independent testing lab? It's pretty common in golf, though the independence part is a little questionable (or the JD Powers auto awards where every model seems to win something).
Click to expand...
I just don’t have the interest anymore, and there are many other things I want to do instead.

Regards,
Dave
 
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