Need Help...Radar Gun...
- Thread starter X Breaker
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Try law enforcement 
I wonder what kind of setup is required for measuring break speeds with a speed gun. As the method for measuring is based on Doppler effect, you'd need to stand in front of the breaker but then you get signals from the moving cue and breakers arms etc. as well. How do you/they separate the cueball speed from all the excess background "noise" ?
I'm currently working on my Master's thesis work on a relating issue...
I wonder what kind of setup is required for measuring break speeds with a speed gun. As the method for measuring is based on Doppler effect, you'd need to stand in front of the breaker but then you get signals from the moving cue and breakers arms etc. as well. How do you/they separate the cueball speed from all the excess background "noise" ?
I'm currently working on my Master's thesis work on a relating issue...
mjantti said:Try law enforcement
I wonder what kind of setup is required for measuring break speeds with a speed gun. As the method for measuring is based on Doppler effect, you'd need to stand in front of the breaker but then you get signals from the moving cue and breakers arms etc. as well. How do you/they separate the cueball speed from all the excess background "noise" ?
I'm currently working on my Master's thesis work on a relating issue...
Very interesting input.
Since radar guns are also used to measure the speed of bat movement, club head speed...etc in various sports, I am pretty sure it can be done.
Can the radar gun be focused on the speed of the cue ball alone?
Richard
drivermaker
Banned
nipponbilliards said:
For such a short distance between the CB and the rack, that's where the real problem lies. Additionally, it also has to do with the relatively low speed of the CB (under 40mph and in most cases under 30). Regular radar guns are programmed and calibrated to register speeds higher than that.
For golf, you can get radar guns that register CLUB HEAD speed and also the initial velocity of the golf ball itself in MPH. Both speeds are quite different from each other. I really don't know what the hell the speed guns that are being used for pool are actually picking up to get their measurements in mph. and if they're properly programmed for the lower speed of the CB itself. I think they're using the "JUG" brand.
try contacting SARDO on this matter. carmine sardo was the one using the radar gun at the US Open this past year. he can probably shed some light on this.
VAP
VAP
I have one that measures whole numbers only, and it works great for breaks. If you want to know more let me know. It Costs between $100 and $200 depending on the features you want. If you want to measure to the tenths place, you are looking at around $1000 bucks...nipponbilliards said:
Let me know if you want more info.
FYI, the fastest break I've timed was Frankie Hernandez at 26 MPH...
-td
I'm also a target shooting enthusiast.
Why couldn't a chronograph be modified to capture a cueball?
They can measure from just a few feet per second up to 7000 FPS.
Dave
Why couldn't a chronograph be modified to capture a cueball?
They can measure from just a few feet per second up to 7000 FPS.
Dave
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drivermaker
Banned
td873 said:
Only 26 mph...Frankie is NOT a powder puff hitter. Based on what you've measured with other players and seen of the women, what do you think the top women would come out at compared to Frankie with YOUR device?
(This is what I'm getting at...the differences and discrepencies in a variety of guns)
Where do you place the unit when measuring break speed and what is the lowest that you've seen it register? Who is the manufacturer and what model is it? What other applications can it be used for...such as golf swing speed, bat speed, auto racing, pitched baseball? If you don't want to post, please PM me.
drivermaker
Banned
Mr. Wilson said:
A FEW FEET per second? And what do you think the elapsed time would be from tip contact on the CB to impact on the rack...what part of a second? Would the human reaction time be quick enough to get it?
drivermaker
Banned
mjantti said:Try law enforcement
Their radar guns are for speeders...not someone lollygagging at 25 miles an hour on a 4 lane expressway that's whacked to the limit on weed.
best way to measure break speed
It's not quick, but I would think the best way to accurately measure break speed would be to calculate it using the time the cueball takes to get to the rack and the distance traveled. It's just plug and chug from there. I guess the hardest part would be measuring the time precisely, but perhaps high speed video could be used or something to that effect.
Since 1 mph is ~ 1.467 fps so a 30 mph (44 fps) break is only going to take about .11 seconds (assuming a distance of about 5 feet). Perhaps lasers could be used to measure the time like in autocrossing (ball breaks the plane of two lasers with a known distance between them). Just thought I'd throw out some ideas...lol.
It's not quick, but I would think the best way to accurately measure break speed would be to calculate it using the time the cueball takes to get to the rack and the distance traveled. It's just plug and chug from there. I guess the hardest part would be measuring the time precisely, but perhaps high speed video could be used or something to that effect.
Since 1 mph is ~ 1.467 fps so a 30 mph (44 fps) break is only going to take about .11 seconds (assuming a distance of about 5 feet). Perhaps lasers could be used to measure the time like in autocrossing (ball breaks the plane of two lasers with a known distance between them). Just thought I'd throw out some ideas...lol.
drivermaker said:
I have some statistical info at home, but from what I remember: the average male pro breaks around 24.5 MPH, and the average female pro breaks around 19.6. Taking into account the inherent erro in off-angle measurements, I would estimate that Frankie's break was actually 5% faster than the gun measured. That 26 is actually pretty good, all things considered.
FWIW, I don't think that the gun itself makes a difference, and in particular, I don't thing my device would fair better or worse against a police radar gun, or a military one. As the techonology is fairly straightforward, any radar gun will be accurate to within a MPH or maybe two, but this is less relevant than the angle you measure the from. I.e., the Cosine Effect results in two measurements that you have to account for when measuring breaks: horizontal AND vertical. Without giving the math, a 15° angle results in about a 3.5% margin of error, and a 30° angle results in about a 13% margin of error. [This is the case with any radar gun.] I use 5% since I measure from about 15° to the side and around a foot above the table as well.
When measuring speed with a radar gun, you should be as close to in front or behind the moving object as possible (on the same planes as the thing you are measuring). However, for breaks, if you stand directly behind or in front, there is a tendency for the machine to register the stick, the shooter, or even the object balls after impact. That's why I measure from 15° to the side... I aim right at the center spot and usually get an accurate reading.
To calculate the speed taking the Cosine Effect into account (at 15°), take the speed, move the decimal in one place (divide by 10) and half the number. Add this to what you started with, and that would be the adjusted speed. (i.e., if the machine shows 18, 18/10 = 1.8 and half of that is .9, so the speed would be 18.9 MPH).
If a player breaks from the side rail, and you measure from the center spot, you are at about 30°. If you are a foot or so above the table, you'll have another 2% error, so that's about 15% off. Take the reading, move the decimal, add that number and half that number to what the machine had. (i.e., if the machine shows 18, take 18 + 1.8 + .9 = 20.7).
*I always tell the shooter what the machine says without the Cosine modification...*
The one I use is a Bushnell Speedster. It measures from 10 MPH to around 200 MPH. It is designed to measure baseballs, but can be used for cars etc. For clubhead speed or baseball bat speed, you really need a chronograph as mentioned above.
If you have any other q's, let me know.
-td
This is what you need... There are also schematics on the internet on how to build your own.
http://www.vernier.com/probes/probes.html?vpg-btd&template=standard.html
Figure out how to make one that fits under the rails on either side of the table and you may get 20 or so people to buy them.
JV
BTW I get a free one for coming up with the idea...
http://www.vernier.com/probes/probes.html?vpg-btd&template=standard.html
Figure out how to make one that fits under the rails on either side of the table and you may get 20 or so people to buy them.
JV
BTW I get a free one for coming up with the idea...
I was thinking about this and I think a simple device could be constructed to ensure consistency and accuracy for measurement. This is based on the same theory (I think) that's used for FPS measurements in shooting (speed measured over a limited distance)
Half-assed diagram for thoughts....
Half-assed diagram for thoughts....
Attachments
B
Bruce S. de Lis
Guest
jaz said:
Looks like a Pool Ball Speed Trap, and I think it would work....
It looks like a few of us posted the same exact idea, for the most part, at pretty much the same time...lol.
F
Fred Agnir
Guest
Johnny "V" said:This is what you need... There are also schematics on the internet on how to build your own.
http://www.vernier.com/probes/probes.html?vpg-btd&template=standard.html
Figure out how to make one that fits under the rails on either side of the table and you may get 20 or so people to buy them.
JV
BTW I get a free one for coming up with the idea...
This is basically the best idea, IMO. The CueTech Pool SChool uses something very similar. As you may remember John, I'm in the automation field. I can build these things in a heartbeat, but it's simply not cost effective.
Fred
F
Fred Agnir
Guest
Rackin_Zack said:
Great minds and all that...
But, to answer the underlying Drivermaker question, the speeds measured by the Cuetech Pool School devise (start/stop non-contact photoswitches) were well within the same expected range as the radar gun measurements. That is, if there was a difference, it'd be difficult to convince anyone that there was a significant difference.
And as stated before, the actual number isn't so important if everyone (men vs. women) gets measured by the same equipment. Long and short: Sarah and Tiffany have been proven by measurement that they break harder than the vast majority of men.
Fred