Joint Pins - What and why

boogieman said:
I'm not a cue maker. I recently got a Shmelke purple heart break cue and had a G10 pin installed just to try it. I heard about the "vibration" thing. I think it's purely marketing BS. If anything I find the G10 annoying because you have to really crank it down to get it to feel like a one piece cue. To me, it almost feels like it makes the cue feel like it has shock absorbers in the pin. It may be a fit and finish issue since it's a relatively cheap cue, but I'm not entirely sold on the playing characteristics of G10. I know my playing cue with the new style (modified?) 3/8 10 feels much more like a solid piece of lumber than the G10 break cue does. This could also be something to do with how a purple heart shaft plays, I don't have the experience to say for sure but it feels more muted than say maple or ash.
Click to expand...
I guess for me I am really used to my Cog. I've experimented with shots and I can get more extreme spin on the ball and I can move the cue ball further in different directions after contact with the first rail than any other cue. Something about it that's better for me. I'll just keep thinking it's the pin so I don't start over thinking it and shark myself
 
Hungarian said:
Okay, thanks. So there's nothing true about the shock wave reflecting back up the shaft when if reaches a metal joint and that that doesn't happen with a plastic pin with a wood to wood connection, therefore the cue resonates all the way down to the butt? Have you heard of this theory before? I'm sure I didn't just dream it up. This is what people have said to me numerous times, and that this was the reason Joe Gold started using G-10.
Click to expand...

our defunct member Dmitry Komarov (RIP) had written a very interesting physical study about wave properties of a cue , it's still on his website :

Investigation in Some Wave Properties of a Billiards Cue | DBKcues

dbkcues.ru dbkcues.ru

he wrote some other & precious articles about ball motion in stun and follow properties ,about collision of billiard balls , and about a cue testing unit
 
erriep said:
our defunct member Dmitry Komarov (RIP) had written a very interesting physical study about wave properties of a cue , it's still on his website :

Investigation in Some Wave Properties of a Billiards Cue | DBKcues

dbkcues.ru dbkcues.ru

he wrote some other & precious articles about ball motion in stun and follow properties ,about collision of billiard balls , and about a cue testing unit
Click to expand...
RIP Dmitry Komarov. What a great scientific mind, incredible engineer and technician and an excellent technical writer.

This is exactly what I was saying all along. Now it's clear to me that Cognoscenti's are the best cues because of their pins and that a logical continuation of this work could be to measure the longitudinal and transverse deformations of the cue with three synchronized piezoelectric sensors, and to compare the results of these measurements for the cues of different designs. hahaha
 
Comparing the hit of a break cue to a playing cue won't give you any information about the type of pin installed.
 
DeeDeeCues said:
Radial is garbage.

The -14 threads together in fewer revolutions for the same length.

QR is basically a gimmick. It doesn't take long enough to put a cue together to worry about.

Loads of people will claim they can feel the difference. I believe they are fooling themselves.
Click to expand...
Why is Radial garbage?
 
IGotLucky said:
Why is Radial garbage?
Click to expand...

The fit is too tight. The geometry of the threads is bad. I've posted about this many times. Screwing with thread form is a fool's errand. Sure, someone may someday create a better thread than the sixty degree thread that has been standardized since the civil war, but it hasn't happened yet.

Just so I don't get the 'what about ballscrews and acme threads?' response: I am specifically talking about threads used for holding parts together, not power transmission threads.
 
DeeDeeCues said:
The fit is too tight.
Click to expand...

No, it is not. Uniloc offers 3 sizes for their taps.
DeeDeeCues said:
The geometry of the threads is bad.
Click to expand...

WRONG.
DeeDeeCues said:
I've posted about this many times.
Click to expand...

So what.


The real discussion should be about the transference of energy in the area between the minor and major thread diameters.

Energy does not transfer at 60 degrees like it will transfer thru the mild rise and fall of the Radial thread.

In the end you did mention how the threads are best for hold, we agree.
 
Last edited:
CuesDirectly said:
No, it is not. Uniloc offers 3 sizes for their taps.


WRONG.


So what.


The real discussion should be about the transference of energy in the area between the minor and major thread diameters.

Energy does not transfer at 60 degrees but it will transfer thru the mild rise and fall of the Radial thread.

In the end you did mention how the threads are best for hold, we agree.
Click to expand...

If the threads are transferring energy, something is wrong. The energy is transferred through the faces.

The rest of your statement isn't worth replying to.
 
DeeDeeCues said:
If the threads are transferring energy, something is wrong. The energy is transferred through the faces.

The rest of your statement isn't worth replying to.
Click to expand...
First off, you said the thread was too tight, I proved you wrong, gave you free advice even, smile, it's a wonderful Monday.
 
Last edited:
DeeDeeCues said:
The energy is transferred through the faces.
Click to expand...
Energy will not transfer thru the 60 degree face like it would in a radial, very different.


The real problem with the radial is the cost, 100 standard pins = $340 whereas 100 radial pins =$1300.
 
Last edited:
CuesDirectly said:
Energy will not transfer thru the 60 degree face like it would in a radial, very different.


The real problem with the radial is the cost, 100 standard pins = $340 whereas 100 radial pins =$1300.
Click to expand...

The energy doesn't transfer through the pin at all. The energy transfers through the faces of the joint.

The only way for impact to travel through the pin is if the faces of the joint aren't touching.
 
DeeDeeCues said:
The energy doesn't transfer through the pin at all. The energy transfers through the faces of the joint.

The only way for impact to travel through the pin is if the faces of the joint aren't touching.
Click to expand...
Agreed for the most part but, when the energy hits the threads of a radial it can carry thru whereas it will not with a deep V thread. Very very minor but if people say they feel the difference, perhaps this is why.

Odd thing is this, you would think the more joint face the better. If so, why are the larger pins better for hitting?

The other big pin I like is the flat center 3/8" pin, much nicer than the full V thread.
 
Last edited:
CuesDirectly said:
Agreed for the most part but, when the energy hits the threads of a radial it can carry thru whereas it will not with a deep V thread. Very very minor but if people say they feel the difference, perhaps this is why.

Odd thing is this, you would think the more joint face the better. If so, why are the larger pins better for hitting?

The other big pin I like is the flat center 3/8" pin, much nicer than the full V thread.
Click to expand...

Do larger pins do a better job holding the two joint faces together without side to side rocking of one face?
 
kling&allen said:
Do larger pins do a better job holding the two joint faces together without side to side rocking of one face?
Click to expand...
I don't do repair work and therefore not as good as others in here on this question but it's most likely a full thread that is the problem.

A full V thread has more room for movement side to side than does a Radial or modified pin with the flat center. Side to side should not be happening at all once tightened.
 
You must log in or register to reply here.
Back
Top