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bluey2king
08-24-2005, 09:11 AM
Hello Dr.Dave I just read your article in Aug. BD. Very good and we have covered some of this here.
My Q is about cue tip contact time. I read it is about .001 of a sec no matter type of stroke (except masse. I saw that the cue shaft deflected about a cue tip on english shots and then vibrated.
Have you tried a cue with the LimbSaver vibration dapening bumber?
I have one on my Break Cue and it has a phnolic (sic) tip it Breaks very good. Seems to help with Vibration. Here is the claim from the limbsaver.com site.

quote "Cue Stick Vibration can cause the tip to wander, greatly decreasing accuracy. The LimbSaver™ X-1 Cue Stick Stabilizer keeps the tip on the ball longer!" end quote.

Can this be true about staying in contact longer? If the vibration happens after the .001 sec. contact would it have any effect on the cue ball?
I would like to know what you think.
Thank You
Bill

dr_dave
08-24-2005, 09:34 AM
<blockquote><font class="small">Quote bluey2king:</font><hr> Hello Dr.Dave I just read your article in Aug. BD. Very good and we have covered some of this here.
My Q is about cue tip contact time. I read it is about .001 of a sec no matter type of stroke (except masse).<hr /></blockquote>
The contact time can vary a little, but it is very close to 0.001 sec for most equipment and most shots. See the "tip contact time" links under "cue stick" in the threads summary area of my website (http://www.engr.colostate.edu/~dga/pool/threads.html) for more detailed information.
<blockquote><font class="small">Quote bluey2king:</font><hr>I saw that the cue shaft deflected about a cue tip on english shots and then vibrated.<hr /></blockquote>
Super-slow-motion clips HSV 4.4, 4.5, and A.5 (http://www.engr.colostate.edu/~dga/pool/high_speed_videos/index.html) show this fairly well.
<blockquote><font class="small">Quote bluey2king:</font><hr>Have you tried a cue with the LimbSaver vibration dapening bumber?
I have one on my Break Cue and it has a phnolic (sic) tip it Breaks very good. Seems to help with Vibration. Here is the claim from the limbsaver.com site.

quote "Cue Stick Vibration can cause the tip to wander, greatly decreasing accuracy. The LimbSaver&amp;#8482; X-1 Cue Stick Stabilizer keeps the tip on the ball longer!" end quote.<hr /></blockquote>
I have not tried this, and I doubt it would affect the shot any; although, it would change the feel of the shot, which could have an affect (even if only psychologically) on how you shoot.
<blockquote><font class="small">Quote bluey2king:</font><hr>Can this be true about staying in contact longer?<hr /></blockquote>
I would doubt it, but high-speed video could answer the question definitively. Also, even if the tip stayed in contact longer, the forces would be smaller during the contact time and the momentum transfer would still be the same (i.e., contact time isn't really that important, physically).
<blockquote><font class="small">Quote bluey2king:</font><hr>If the vibration happens after the .001 sec. contact would it have any effect on the cue ball?<hr /></blockquote>No. But it will change how the shot feels.

Regards,
Dave