changing pivot point on a cue

[Bob Jewett]

Not if done for private use, as described. It's not being manufactured for sale.

pj
chgo

I am not a patent atty, but I'm pretty sure that making it for private use is illegal. It would be tough to prosecute, though.

 

[12squared]

thanks hollywood.

i dont have the billiard digests as i live in belgium, but ill check out with some guys here if someone has the article.

Here's Dr. Dave's website. All of his Billiard Digest articles as well as many high speed videos & much more can be found here: www.engr.colostate.edu/~dga.

Hope this helps.

Dave

 

[Solartje]

You're welcome Solartje. A couple of points.

First, the squirt figures he cites are given in terms of the amount of sideways "deflection" of the cueball after travelling 50" when hit at a specific offset. (He took averages of 6mm and 12mm for the offsets which equals 9mm) . The deflection numbers can be converted to pivot point distances easily enough.

The first Predator shaft squirts about 75% that of a "typical" cue. It's pivot point is about 12" back from the tip, so you could use backhand english (BHE) with it if you wanted to employ that longish bridge length.

He's also measured the change in squirt with shot speed for several different cues and found only a very slight increase over a broad range of speeds. It's so slight that it's almost a miracle if he was able to do this with some accuracy. This should apply to all cues including your J&J. Laminations should not make a difference either way as far as the influence of speed is concerned. They provide more radial consistency (ie, it matters less how the cue is oriented in your grip hand).

I'm assuming the cuemaker could remove the ferrule without damaging it or get a replacement if necessary. I'm not a cuenmaker either so I don't know for sure.

Some people have thought that his squirt figures are way too high for the "low" squirt cues, but Dr. Alciatore's measurements back them up.

Jim

Hi jim,

thanks again. i think i misexplained something probably, because the speed really does matter alot. the thing is: if u play at a 3lenghts-speed the cueball wont swerve as much then if u play with low speed, making the speed influence the bridgelenth (aka why i want 5 different rings at different distances on the shaft).

But as what you say is true, that means, that the squirt doesnt change, but the swerve does change with different speeds.

meaning that using a laminated shaft or a regular shaft wont change, as this aply's for both type of cue's. So pritty much any shaft would do. right?

i just need to calculate what the formule is that relates weight at the tip vs pivotpoint, and then find the right ferule, tenon, wood combo so it has the right weight that suites my regumar bridgelenth.

then i'll have my dream shaft

talking about patents, i'll patent it just for the fun.

gonna do some math this week and check what weight i need. then i need the different weights of ferule types, etc to find the combo. i'll need help on that

I really think i've got a good idea here. if it works, this shaft will help me shoot enlgisch shots just as easy as straight in shots (with some minor adaptments in function of (table, cloth, cleaness of balls,contact inuced throw, humidity, etcc) easy . perfect

at least i wont be disconcentrated by having the turn my cue, untill i see the marking on my shaft that i use now. 5 rings would be perfect i think. not to much, not to few

 

[Patrick Johnson]

I am not a patent atty, but I'm pretty sure that making it for private use is illegal. It would be tough to prosecute, though.

Seems you're right. I wonder what I was thinking of...

pj
chgo

 

[Jal]

Hi jim,

thanks again. i think i misexplained something probably, because the speed really does matter alot. the thing is: if u play at a 3lenghts-speed the cueball wont swerve as much then if u play with low speed, making the speed influence the bridgelenth (aka why i want 5 different rings at different distances on the shaft).

But as what you say is true, that means, that the squirt doesnt change, but the swerve does change with different speeds.

You're welcome again Solartje. Yes, what you say about the swerve changing with speed, but not the cue's intrinsic squirt, is, I think we can say, the general understanding (and is very likely right).

meaning that using a laminated shaft or a regular shaft wont change, as this aply's for both type of cue's. So pritty much any shaft would do. right?

Yes. The only thing is, if you start out with a Predator, at least you have a pretty good idea (from the Platinum Billiards data) of where the unmodified shaft's pivot point is located. You could then work directly, more or less, from Steve Titus' test results. Just a thought (which was your original plan to begin with, no?)

i just need to calculate what the formule is that relates weight at the tip vs pivotpoint, and then find the right ferule, tenon, wood combo so it has the right weight that suites my regumar bridgelenth.

then i'll have my dream shaft

talking about patents, i'll patent it just for the fun.

gonna do some math this week and check what weight i need. then i need the different weights of ferule types, etc to find the combo. i'll need help on that

If I can be of service, let me know. I think I'd feel more confident trying to figure the necessary added weight and where to put it when working as directly off of Steve's numbers as possible (ie, trying to keep everthing else the same), but maybe you'll put more effort into the analysis.

Jim

 

[Jal]

I am not a patent atty, but I'm pretty sure that making it for private use is illegal. It would be tough to prosecute, though.

But you can buy a product and modify it for one's personal use, no? Beyond voiding the warranty, would there be any other ramifications?

Jim

 

[Flex]

But you can buy a product and modify it for one's personal use, no? Beyond voiding the warranty, would there be any other ramifications?

Jim

Heck, Varney modifies Predator 314s by the hundreds, doing something special to the ferrule to improve the hit...

 

[Bob Jewett]

But you can buy a product and modify it for one's personal use, no? Beyond voiding the warranty, would there be any other ramifications?

Jim

If you use some patented method in the modification, you are violating the second patent. Lots of things you buy are covered by patent, and in general you can customize them.

 

[Jaden]

Not if done for private use, as described. It's not being manufactured for sale.

pj
chgo

If I were to create a shaft using both laminated eight point wood and used a foam core of similar length and other specifications, and then sold it, it would be a violation of the patent. Otherwise, I can do whatever I want and it would not be in violation of the patent. Patents are to protect inventors from the manufacture and sale of their inventions, not from the private use of an individual.

Besides, all I did was make it more like a standard shaft that happens to be radially laminated. That's not a violation of anything but predator's warranty.

 

[LILJOHN30]

tenion

Somewhere on the site I've actually posted what I did with my 314 on a predator that I am now using as a break cue but at one time used as a playing cue. I cut off the tenon and ferule and drilled out the foam core and added a new tenon. The low deflection, low squirt shafts usually have some method of decreasing the end mass of the shaft like with the predators removing putting a foam core and drilling out the centers of the end of the shaft. If you go to a,most any cue repairman or cue maker they should be able to do what I did.

I have a predator 314 2nd gen and had the same work done.I had the shaft drilled and a new tenon installed with a melamine ferule installed after my other ferule came off.I had one of the defective shafts with bad glue.I love the what it hits now.