He is right here guys. Also the stiffer shaft is like the heavy guy. The stiff shaft does not want to move so it shoves the cue ball. The cue ball has no support so it squirts.
A Closer look at L.D. Shafts
- Thread starter Barioni Cues
- Start date
He is right here guys. Also the stiffer shaft is like the heavy guy. The stiff shaft does not want to move so it shoves the cue ball. The cue ball has no support so it squirts.
John, this one post is so alarming, you have no idea.
Let me ask a simple 2-part question:
1. When you say you tested at different flex points and then you mix in the words "pivot" and "bridge," how are you changing the flex point in order to test?
2. From your early summation that stiff has more squirt than flexible, is that based on your experiment in this post quoted above?
Thank you.
Freddie <~~~ suggests John calls
But stiffer shafts can squirt less than more flexible shafts if they have less end mass (this is the case with my very-low-squirt but very stiff shaft), and vice verse (more flexible shafts can squirt more). This means that, if stiffness is a factor, it's less of a factor than end mass - tests so far seem to show that it's far less (at least for shafts in the normal range of stiffness/flexibility), maybe negligible.
pj
chgo
Just a part-time thinker here....
On average could it be that stiffer shafts are more dense than more flexible shafts and therefore tend to be heavier, creating more end mass, and by extension more squirt?
Well I have two machines that I use and there both pictured at the beginning of this thread. I tested different bridge lengths on the robot or dyno. This machine is the holy grail. It tell you what is better but you have to figure out why. The stiffness tester tell you what is more flexible. It enables you to check the flexibility of a shaft at all spots from the tip to the joint. The best testing shafts in the robot are all flexible. The stiff shafts squirt so much I don't know how people can even shoot pool with them. I am just glad I don't have to deal with it in my pool game.
For your second question yes but I have been doing this study for almost a year now. It has taken this long to test every thing and all the variables. We just finished all the testing. I needed a lot of proof and I also needed to be able to back up what I say and be able to prove it. So for any non believers I will post the cash. And I can show and prove every point. But again I can't take all the credit. I could not have figured it all out on my own. I had help and a lot of it.
Really, May I ask why?
I just thought that it might be helpful and I thought that I would try to give something back to pool. If many of you feel this way please let me know. I will spend the time that I am investing here playing pool or with my family.
John,
One man, one opinion. Don't sweat it. Just keep on discussing your study. It's all good. Most of us appreciate your efforts.
Stiff VS. Flexable
I would like to touch up on this a bit. When I say a stiff shaft squirts more I need to go further on this. Here is what I did and also how I can prove it. I took a stiff shaft and put it in the dyno. I recorded the results. I tested it at different speeds with different amounts of english. Then I tested it again in the dyno but this time I did not change any thing on the dyno. So basically I fired the shot, it made a dot on the striking board. I took the shaft off but left the butt still in the dyno. Then I took that same shaft and started weakening it or making it more flexible. I recorded the flexibility changes as I went. I first started at the tip and progressed towards the joint. Here are the pics of the stiffness or flexibility tester and also the shaft. The shaft I am talking about is the second one from the bottom. The first groove improved squirt by 3/16". The rest of the grooves for the first six inches made it worse. Then at 12" it improved squirt by 7/8". Here is what happened. The first groove closest to the tip improved squirt because it removed some of the mass and lightened the front end. The second, third, and forth groove increased squirt. Here is why. The tip buckles at contact and wants to wrap around the ball. For this split second the contact point tangent line is increased. The shaft buckled before it had time to move out of the way. For a shaft to play its best it needs to be stiff for the first 7 or 8 inches and then get flexible. So basically if the pivot point is any where near the first 6 or 7 inches it will cause a lot of squirt. Making the pivot farther back improves squirt. Making it more flexible farther back improves squirt. Over all when the shaft was at its most flexible state it produced the least squirt. This got me on to trying different shaft tapers. Jack Kohler states in his book that shaft flexibility is 70% of the performance. I thought he was high! Turns out he was not. The taper of a shaft can reduce squirt by as much as 40%-65%. So months of testing went on hoping to find the best taper. Cut a shaft, test it. Re-cut the same shaft ,test it. This went on and on with many different shafts. So here is the nuts! There is no one perfect taper. The perfect taper for one shaft may not be perfect for another. A denser shaft with more growth rings has to have a slimmer or more flexible taper than a lighter shaft with less growth rings. Now you can do other things to compensate for the stiffness if you want to keep the taper the same but now we are getting into shaft tuning. I encourage all of you to go to youtube and search for arrow tuning and spine testing in archery. Archery is years ahead in research and development. It deals with the mass of the arrow head in conjunction with the shaft flexibility. Getting a arrow to fly straight is similar to getting a shaft and cue ball to go straight. And ya, they have robots to fire the arrow and flexibility testers.
By the way, the high performance Bow and Arrows do not use wood any more. Just like golf clubs, tennis rackets,etc.
I would like to touch up on this a bit. When I say a stiff shaft squirts more I need to go further on this. Here is what I did and also how I can prove it. I took a stiff shaft and put it in the dyno. I recorded the results. I tested it at different speeds with different amounts of english. Then I tested it again in the dyno but this time I did not change any thing on the dyno. So basically I fired the shot, it made a dot on the striking board. I took the shaft off but left the butt still in the dyno. Then I took that same shaft and started weakening it or making it more flexible. I recorded the flexibility changes as I went. I first started at the tip and progressed towards the joint. Here are the pics of the stiffness or flexibility tester and also the shaft. The shaft I am talking about is the second one from the bottom. The first groove improved squirt by 3/16". The rest of the grooves for the first six inches made it worse. Then at 12" it improved squirt by 7/8". Here is what happened. The first groove closest to the tip improved squirt because it removed some of the mass and lightened the front end. The second, third, and forth groove increased squirt. Here is why. The tip buckles at contact and wants to wrap around the ball. For this split second the contact point tangent line is increased. The shaft buckled before it had time to move out of the way. For a shaft to play its best it needs to be stiff for the first 7 or 8 inches and then get flexible. So basically if the pivot point is any where near the first 6 or 7 inches it will cause a lot of squirt. Making the pivot farther back improves squirt. Making it more flexible farther back improves squirt. Over all when the shaft was at its most flexible state it produced the least squirt. This got me on to trying different shaft tapers. Jack Kohler states in his book that shaft flexibility is 70% of the performance. I thought he was high! Turns out he was not. The taper of a shaft can reduce squirt by as much as 40%-65%. So months of testing went on hoping to find the best taper. Cut a shaft, test it. Re-cut the same shaft ,test it. This went on and on with many different shafts. So here is the nuts! There is no one perfect taper. The perfect taper for one shaft may not be perfect for another. A denser shaft with more growth rings has to have a slimmer or more flexible taper than a lighter shaft with less growth rings. Now you can do other things to compensate for the stiffness if you want to keep the taper the same but now we are getting into shaft tuning. I encourage all of you to go to youtube and search for arrow tuning and spine testing in archery. Archery is years ahead in research and development. It deals with the mass of the arrow head in conjunction with the shaft flexibility. Getting a arrow to fly straight is similar to getting a shaft and cue ball to go straight. And ya, they have robots to fire the arrow and flexibility testers.
By the way, the high performance Bow and Arrows do not use wood any more. Just like golf clubs, tennis rackets,etc.
Attachments
John, have you compared unmodified shafts of different stiffnesses and found the same results?
pj
chgo
pj
chgo
Mr. Barioni,
Did you do a test of a conical tappered shaft & then turn it to a pro taper for a comparison. I'd be interested as I have played with regular conical tapered shafts for 45 years & have just switched to LD pro tapers.
Thanks in advance for any info you can share,
Did you do a test of a conical tappered shaft & then turn it to a pro taper for a comparison. I'd be interested as I have played with regular conical tapered shafts for 45 years & have just switched to LD pro tapers.
Thanks in advance for any info you can share,
Does mean when the cueball gets hit, that block is either closer or farther from the tip. In other words, maybe a 3" bridge length tested, then a 6", then a 12"?
Freddie <~~~ now really thinks John should have called
Hi Patrick,
Yes I have. In fact I test all she shafts unmodified as once I modify them I could not go back and test them in the unmodified state. So the first thing I always do it test the shaft first to establish a base line and a beginning or starting point. Then every thing that happens after that gets tested and recorded each step of the way.
Yes, but I had to do this on about 5 different shaft because the first conical tapered shaft had a 12mm tip end. I still put a pro taper on it but then it was so flimsy so I made a few more to make sure the test results were were accurate and not being influenced by a real flexible shaft. The pro taper out performed the conical taper in all five shafts for squirt.
Yes. And the arm is at 90 degrees at contact in each case hitting the same spot on the cue ball.
Here's the thing. Say you have a shaft that has a 12mm tip with no taper and it measures 12mm a foot fom the tip. Then you have a shaft of the exact same wood that has a 12mm tip but tapers to 13mm a foot from the top.
This is a wrong comparison because the conical taper is going to be heavier for that last foot of the shaft. In this case for a conical taper, you need to compare a shaft that is, say, somewhere around an 11.5 mm tip that tapers to 12.5 mm 12" from the tip (I haven't done the math) to your 12mm stright taper. You need to calculate comparable end mass.
John, you should really call Fred and Patrick - have them make some suggestions for your experiments, and get their knowledge of physcis working for you. They have both have already extensively studied this. Patrick made a shaft that has a lot less squirt than anything on the market but is stiff. Fred is an engineer who is a good player and is well respected at evaluating cue performance. They can also help you interpret the results.
These guys are scientifically oriented and know their stuff.
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And Bob Jewett and Dr. Dave Alciatore and Mike Page....