Thanks JB. Nice to see familiar friends are still active here. I got inspired by the Mosconi Cup to start browsing here again. I guess it's apt to send a big g'day to all old acquaintances.welcome back!!
Thanks JB. Nice to see familiar friends are still active here. I got inspired by the Mosconi Cup to start browsing here again. I guess it's apt to send a big g'day to all old acquaintances.![]()
There is no doubt that ultimate tests are performed by robots,
Petros
Well… there's always a doubt. The issue with using "robots" is that if the user/tester doesn't understand where a robot can falsely influence the test, then the result can get very misleading. Period.
The Meucci "robot" has an issue that may never get changed. Copiers of that system will potentially have the same issue. And even Iron Willy had a robot issue that the Jacksonville Experimenteers had to … iron out (har har ) .
Freddie
I don't think a tip of any design can "overcome" the amount of squirt (cue ball deflection) created by a shaft (conventional or LD). Now, what is clear from the testing video is that some tips add more squirt than others. In the tests, the amount of squirt increased with the hardness of the tip. This makes sense because a harder tip is denser and heavier, create more "endmass." For more info, see the cue tip hardness effects resource page.It looks like a tip may not be able to overcome the amount of deflection created by a conventional shaft that has high end mass...Watch the video again. It might help to watch it more than once.
The LD shaft had much less deflection than the shaft on which multiple tips were tested. However, the tip type, hardness, and height didn't make much difference in the results for the shaft on which I did the tests.
To answer your question directly, the "low-squirt tip" did not produce less squirt (cue ball deflection) than the others in my tests
I agree that swerve can corrupt squirt-testing results significantly. The best and most convenient way to deal with this is to keep the cue as level as possible, use fast speed, and test on very slick cloth. All of these things help minimize swerve. If the cue elevation and/or shot speed are varied, any cue or tip can be demonstrated to have any amount of net cue ball deflection (the combined effects of squirt and swerve).The next observation I had was that Jaden's low speed testing introduced swerve...
Would it be practical to create a shorter test bed where there was little chance of swerve to establish for sure that squirt doesn't change at different speeds and only swerve is introduced if there is adequate distance and surface friction for the ball to spin back to the original target.
...
Would craft paper/or maybe wax paper be slick enough to eliminate swerve or would you likely need something with even less friction??
Colin,Jaden, this is genius, mega impressed and can't wait to try some of your tips. It's bleeding obvious that tip materials / design could play a significant role. The days of homogeneity and layering may soon be over thanks to your work.... huge pat on back!
Colin
Freddie,Well… there's always a doubt. The issue with using "robots" is that if the user/tester doesn't understand where a robot can falsely influence the test, then the result can get very misleading. Period.There is no doubt that ultimate tests are performed by robots
The Meucci "robot" has an issue that may never get changed. Copiers of that system will potentially have the same issue. And even Iron Willy had a robot issue that the Jacksonville Experimenteers had to … iron out (har har ).
What we agree on is that if a robotic machine were designed and built very well, and if testing procedures were such that all important factors are taken into consideration, then the robotic machine results would be much more accurate and consistent than any human testing results could be. The problem with all robotic testing machines designed, built, and used for testing in the past is that they haven't met this ideal description as well as one would hope. For examples of some of the issues that have put previous testing results into question, see the bullets on the robot test results and advice resource page.All this is very interesting, I get the feeling we agree when it seems we don't.
Since a totally level robotic cue movement eliminates swerve it is what we need for this kind of testing, no human hand can approach the accuracy of robotic movement.
An experienced instructor/player with knowledge of the game can estimate all parameters that can mislead conclusions of robotic testing, so I don't see any problem combining all kinds of testing.
There is no logical reason to "refuse" robotic testing if available and no testing method that requires accurate repetition of movement can be 100% complete without it.
Petros
Until we can fund, design, and build high-quality machines and carefully design testing procedures that take all important effects into consideration, the best we can do is careful human experiments with multiple human subjects and multiple trials (throwing out bad data according to a careful procedure) and use averages to get meaningful results.So if robotic machines are not made up to the desired standards yet (agreed) where does that leave any human mediated effort?
In my recent tip squirt-testing experiments, the largest difference in squirt (cue ball deflection) seen among the wide range of tips tested was 2 3/8" for a hard and heavy phenolic tip compared to 2 1/8" for the softest and lightest leather tip. That difference is about 12%. That difference would certainly be noticeable to a top player playing on tight equipment, but I agree that the tip doesn't make much difference in general (especially when comparing typical tips on typical playing cues).the difference in the mass of the tip, no matter what it is made of..... is insignificant...
Until we can fund, design, and build high-quality machines and carefully design testing procedures that take all important effects into consideration, the best we can do is careful human experiments with multiple human subjects and multiple trials (throwing out bad data according to a careful procedure) and use averages to get meaningful results.
Also, when doing squirt (cue ball deflection) testing, we need to make sure the cue is as level as possible, use fast speed to minimize swerve effects, and use a slick cloth to further minimize swerve effects. I personally think the procedure outlined and demonstrated in my recent tip squirt-testing video is fairly reliable, and I would expect other people to get similar results if they performed the experiments with the same care. Also, providing clear video of the testing helps provide proof that everything was done properly and carefully (or not).
Regards,
Dave
Roger,This is an interesting thread to me since I have argued with Dr. Dave in the past about the values of previously-conducted squirt tests - both robotic, and manual. I had maintained that squirt could be almost entirely eliminated as long as the tip struck the cue ball above the horizontal axis, and is struck with as level a cue as possible.
A graphite cue can be very light on the end; although it can also be very stiff. The lightness factor reduces the actual "endmass," but the stiffness factor actually increases the "effective endmass." For more info, see the squirt endmass and stiffness resource page.So, in my quest to prove my own theory on this matter, I built a fixture that would allow me to hit the cue ball at a consistent height above the horizontal center line (1/2 tip), and at a consistent butt elevation (clearing the rail by 1/2-inch). A few minutes ago, I finished my first round of tests. I started out by testing a one-piece graphite cue because I figured it would be the stiffest, and highest end mass cue I could find. To my surprise, it delivered a highly noticeable amount of squirt.
... or your cue elevation, shot speed, and cloth conditions were just right for the amount of swerve to cancel the amount of squirt for the particular shots you were testing.My point here is twofold. For starters, when I earlier thought I was eliminating squirt with a "proper" hit, I really must have been subconsciously "steering' the cue ball to make it go where I wanted it to go.
Good point. Tests must be done very carefully using good statistical methods.And second, I believe that everything that has been said about the inaccuracies of both manual and robotic testing, are true. One set of tests by either method does not conclusively prove a whole lot.
To me, that is a powerful and useful conclusion. The testing may have helped you improve your understanding of squirt and swerve effects. To me, that is of value.Even my own testing has not really proven anything to me, other than the fact that my previous theory was wrong.![]()
Thanks Dave,Colin,
It's great to see you back on the forum. I hope you stay around for a while. When I think of posters who have contributed the most interesting and useful insight over the years, your name is definitely near the top of the list.
BTW, even though Jaden's tip doesn't seem to reduce squirt (based on the testing results in the video I posted), I agree with you that his design is innovative and represents good out-of-box thinking.
Catch you later,
Dave