Cue's hit

StrokeAnalyzer

StrokeAnalyzer

AzB Silver Member
Silver Member
The new release of StrokeAnalyzer has the ability to capture and analyze stroke acceleration in 3 axis (X,Y and Z). The measurement and analysis of stroke acceleration is useful for instructors or students to measure and quantify what a good or poor stroke acceleration looks like. Stroke steering is easily seen also in the X axis data. The Y axis data might be useful to analyze a piston type stroke.

So what does stroke acceleration have to do with a cue's hit? Well Im not sure. However, during the capture of acceleration data, I noticed some interesting data AFTER the cue hit the cueball. Im not sure what it means or if its useful, but it MIGHT be useful to compare or characterize cues that are known to have a "firm hit" with cues that dont have a similar hit. Ill leave the usefullness of the acceleration data as it applies to cue production and design data up to cue makers to decide. I just wanted to post the data here for discussion.

The data shown below was captured at a 2ms rate. Thats fast enough to see frequencies around 500hz. The bottom waveform is the Z axis (stroke axis). Notice the increasing acceleration before the cue hits the cueball, then the sharp decrease where the cue hits the cueball. After that...you see the vibrations and reflections up and down the length of the cue. The upper waveforms display the X and Y axis acceleration. Probably not as useful...but interesting. You can see a picture of the hardware attached to a cue on the screenshots webpage at the StrokeAnalyzer website.

Im going to post this in the Main forum and the "Cue Machinery and Supplies" forum also just to see if it lights a fire somewhere.

Interesting? Useful?
Bob
sales@strokeanalyzer.com
www.strokeanalyzer.com

SA.gif
 
Stroke, I know your hearts in the right place, but you lost me back there when the accelerator stuck. :smile:
 
I'm intrigued...
I guess now my questions would mount...
Tip type and firmness?
Shaft type (standard or ld), thickness and wood type?
Joint size and metal type?
Weight of cue and length?

Then what's the comparable data to a different cue?

Achieve a "best" baseline with known favored cues and composition and make a cue accordingly...
 
Hey there Stroke, that looks good. That will be a helpful tool to determine lateral movement at contact I think, which can be a culprit is establishing side spin in what seems like a straight stroke. Look forward to trying it out.

Thanks for the tool...
 
Questions....

1. Where is your accelerometer mounted? Near the bumper? The joint? Elsewhere? (Edit: after visiting your site, it looks like there is no accelerometer, but visual targets tracked by a camera?)

2. Is the vertical blue line indicating the moment of impact? If it is, then....

3. It appears that you are measuring velocity and the slope of the curve indicates acceleration.
 
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I am not going to pretend to understand this i know i want to accelerate through the cue ball at contact. I think my feel for the speed and my accuracy of my stroke is to advanced to be duplicated with a computer to many variables in shots. I do admire the effort to find training aids for pool. Hope it turns out great if i see that a player gets useful feedback in a realistic form that i can understand i will love to use it.
 
Shaft said:
1. Where is your accelerometer mounted? Near the bumper? The joint? Elsewhere? (Edit: after visiting your site, it looks like there is no accelerometer, but visual targets tracked by a camera?)

2. Is the vertical blue line indicating the moment of impact? If it is, then....

3. It appears that you are measuring velocity and the slope of the curve indicates acceleration.
Click to expand...

The accelerometer is mounted on the butt end of the cue. You can see that on the screen shot webpage. The sensor is a true accelerometer measuring acceleration in 3 axis.

The blue line is only a marker used to see data across 3 axis. The internal auto calculation measures stroke acceleration by finding the peak accelration then looking back through the data to find the 0 acceleration point...then calculates the final stroke's acceleration in g's/sec. What's a good stroke acceleration? Up to the user/instructor to decide. I personally think this tool is best used to help a person/student/instructor to develope a better stroke by showing what a good stroke looks like compared to a poor stroke. We have all seen someone poke or hesitate during the final stroke. Showing someone what a poor vs good stroke looks like should help explain or show proper stroke mechanics.

This thread is more about what the EXTRA data after the cueball is hit means or might be useful for.
 
It looks to me that you are dropping the but durring the acceleration movement and then the cue is moving left as you contact the ball.

The dropping moment is natural with the pendulum stroke the movement to the left is indicative of an elbow problem at delivery.
 
MitchAlsup said:
It looks to me that you are dropping the but durring the acceleration movement and then the cue is moving left as you contact the ball.

The dropping moment is natural with the pendulum stroke the movement to the left is indicative of an elbow problem at delivery.
Click to expand...

Yep I think thats a pretty good description of what the data shows. The stroke captured is a classic pendulem stroke. There is some side to side movement, however its pretty small.
 
zzzzzzzzzzzzzz

I only use my z stroke when i drill for water .
my y stroke or side to side stroke just never cut it , i think i will try a hockey stick

my x had a stroke and she dont stroke no more.

I think i need a new avatar everyone can call me stroke -less :thumbup:

MMike
 
If my stroke was ever analyzed, I think it would resemble a sperm cell swimming upstream! :grin-square:
 
My last stroke accelerator was female, 19 years old, pool player, 5’4” tall, blonde hair and 95 pounds of pure dynamite. Nearly gave me a heart attack several times in one night. She had a gorgeous body but like pool playing women everywhere, her face would haunt a house.
 
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Looking at your mounting, I see where some of the artifacts are being generated.
The Z axis force is increases due to the cue slowing, the force decreases as the mounting material is compressed, then the force spikes as the accelerometer housing bottoms out.
The ringing is caused most likely by the lack of rigidness of the mounting, plus the vibration of the accelerometer enclosure.
If the hit you measured was a perfect center ball stroke, there would ideally be zero X or Y components.
The cable ideally should be as light weight as possible, and should exit the enclosure on the center of the Z axis.
As mounted, the cable torques the enclosure, as the cable does not decelerate when the contact is made, but keeps on travelling at its original velocity until the enclosure drags it to a stop.
The cable component could be minimized a small amount by making a small loop toward the cue and tie wrapping it to the cue.
If you could make the enclosure no bigger in diameter than the end of the cue, plus make the mounting much more rigid, you'd be surprised how much better the data will look.
Most of the 3-axis accelerometers I use at work are less than .5" square.

Regards,
Howie
 
Howie raises good points: some of the trace could be artifacts of the mounting.

Also, some of the trace could be oscillations in the cue after impact. This info could be useful in developing quantitative measures of "hit" and "feel," which up to now remain purely subjective.
 
howiesatwork said:
Looking at your mounting, I see where some of the artifacts are being generated.
The Z axis force is increases due to the cue slowing, the force decreases as the mounting material is compressed, then the force spikes as the accelerometer housing bottoms out.
The ringing is caused most likely by the lack of rigidness of the mounting, plus the vibration of the accelerometer enclosure.
If the hit you measured was a perfect center ball stroke, there would ideally be zero X or Y components.
The cable ideally should be as light weight as possible, and should exit the enclosure on the center of the Z axis.
As mounted, the cable torques the enclosure, as the cable does not decelerate when the contact is made, but keeps on travelling at its original velocity until the enclosure drags it to a stop.
The cable component could be minimized a small amount by making a small loop toward the cue and tie wrapping it to the cue.
If you could make the enclosure no bigger in diameter than the end of the cue, plus make the mounting much more rigid, you'd be surprised how much better the data will look.
Most of the 3-axis accelerometers I use at work are less than .5" square.

Regards,
Howie
Click to expand...

I agree with you and have thought about the mounting hardware causing some of the oscillations seen after cb impact. The packaging was designed to not damage the cue and measure stroke acceleration BEFORE impact with the CB. The mounting could easily be modified to attach the accelerometer more rigidly to the cue for better measurement of cue dynamics AFTER impact.

Thanks for your comments
 
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