Shafts with Pilots

[pdcue]

Yeah Royce you're right that I'm sure my small tests don't have a true "control" and will concede that my result have limits. I would like to say though that in the least just for the sake of my own thought to my common sense, if I'm going to own or make a cue with a piloted joint I'm going to want it be with a compression fit so it gives more surface contact and at least a "perception" of a better connection which MAY lead to a better feel. Thanks for jumping in Royce. I hold in high regard your opinion as well and your contributions to this forum!... Tim

This falls into the category of 'a distinction without a difference'. A bit of reading
into Physical and Engineering sciences would lend itself to illustrating some
of the reasons why there usually is a point past which there is no discernible
difference.

In your case - the basic assumption that 'more contact area = more transference;
is, quite simply, not correct.

FWIW - as Royce has so eloquently explained, the reason for what is now perceived
as a compression fit, was only for alignment. The amount of force required to screw
the shaft onto the butt has nothing to do with how tightly the pin holds the two together - which does matter.

Dale

 

[RBC]

Right back at ya Royce! For the past few years I haven't been to too many events unless it's in the Midwest and the stars align just right.:smile:.. I would like to start going to the expos again when Keith (Josey) can attend as well since that's who I work with. I would love to meet someday and talk cues or just say "hey":smile:

Tim

I look forward to it.

I didn't realize that you worked with Keith, please tell him I said hello. You're hooked up with some great people there.

As for events we do, It's pretty much just the Super Billiards Expo, the BCA Trade Show, and a couple of the national team tournaments in Las Vegas. I'm in Vegas right now in between those events.

I'm sure we'll run into each other somewhere.

Be Safe!

Royce

 

[HawaiianEye]

I believe differently... The compression fit allows better and more complete contact with the joint. The same cue using two shafts, one with a compression fit shaft pilot and one without will have a different feel. Compression is more solid IMO...

I agree 100% with you. I was writing the same thing in my OP, and got tired of typing and deleted it. You saved me some typing.

I have piloted and non-piloted shafts that will fit a couple of the same cues and when I try them all out with the various combinations, none of them hit the same as the ones that actually have the pilots that "fit" the cue it was made for.

I was trying this out just last Sunday and there is a noticeable difference in the hit and sound. I think some of the reason is because of the "void" in the joint when using the shafts without the "fitted" pilot. The compression joint "fills" the void completely and gives more surface area to the two pieces connecting together. The joint without the compression fit leaves a "small" cylindrical "void" between the pin and the inner walls of the joint. You have a small "air pocket". It may be all in our heads, but I can tell the difference in the hit and the sound.

 

[ElCorazonFrio]

The amount of force required to screw
the shaft onto the butt has nothing to do with how tightly the pin holds the two together - which does matter.

Dale

Actually, the force required does, very much, have something to do with how tightly the pin holds the pieces together.

The formula for axial force applied by a screw is: F(axial)= T/(c*D)
Where:

c=coefficient of friction
D=screw diameter
T=applied torque

So, since we are using our hands to screw these together, there is a definite limit to the amount of torque we can apply. If any of that torque is used to overcome tight threads or a 'compression' fit, then that torque is effectively subtracted from our tightening torque which counteracts the friction forces between the clamped faces.

This is why crap like overly tight thread fit and flat-bottom aligning screws bug the hell out of me.

 

[RBC]

I agree 100% with you. I was writing the same thing in my OP, and got tired of typing and deleted it. You save me some typing.

I have piloted and non-piloted shafts that will fit a couple of the same cues and when I try them all out with the various combinations, none of them hit the same as the ones that actually have the pilots that "fit" the cue it was made for.

I was trying this out just last Sunday and there is a noticeable difference in the hit and sound. I think some of the reason is because of the "void" in the joint when using the shafts without the "fitted" pilot. The compression joint "fills" the void completely and gives more surface area to the two pieces connecting together. The joint without the compression fit leaves a "small" cylindrical "void" between the pin and the inner walls of the joint. You have a small "air pocket". It may be all in our heads, but I can tell the difference in the hit and the sound.

Hawaiian

You do realize that there is a void even with the compression fit joints, don't you?

The void is below the pilot.

As for the transfer of sound, I'd like to clarify a couple of things.
When the cue ball is struck, there are 2 types of vibrations that occur. One is a physical side to side shake of the cue, which is often called a Transverse Wave. The other is really a pressure wave that runs up and down the cue. The transverse wave requires actual movement from the cue, so it progresses down the cue very slowly. Only a few inches of the end of the shaft is in movement while the tip is on the cue ball. The pressure wave, or really a sound wave, doesn't require any movement. It rings back and forth up and down the cue. It's speed is really determined by the speed of sound through whatever materials it's traveling through. This is where the sound of the hit comes from. Personally, I believe that the pressure wave will make it's way up and down the cue with very little, if any, difference between a cue with a small void versus one without the void. The surfaces that can carry that linear "up and down the cue" pressure wave are more than adequate to do the job. The lateral surfaces of the tight fitting pilot wouldn't have any effect on this sound wave because it's a linear wave, and not a lateral one.

I'm certainly not an engineer, but this is how I've put it together with my limited knowledge.


Royce

 

[HawaiianEye]

Hawaiian

You do realize that there is a void even with the compression fit joints, don't you?

The void is below the pilot.

As for the transfer of sound, I'd like to clarify a couple of things.
When the cue ball is struck, there are 2 types of vibrations that occur. One is a physical side to side shake of the cue, which is often called a Transverse Wave. The other is really a pressure wave that runs up and down the cue. The transverse wave requires actual movement from the cue, so it progresses down the cue very slowly. Only a few inches of the end of the shaft is in movement while the tip is on the cue ball. The pressure wave, or really a sound wave, doesn't require any movement. It rings back and forth up and down the cue. It's speed is really determined by the speed of sound through whatever materials it's traveling through. This is where the sound of the hit comes from. Personally, I believe that the pressure wave will make it's way up and down the cue with very little, if any, difference between a cue with a small void versus one without the void. The surfaces that can carry that linear "up and down the cue" pressure wave are more than adequate to do the job. The lateral surfaces of the tight fitting pilot wouldn't have any effect on this sound wave because it's a linear wave, and not a lateral one.

I'm certainly not an engineer, but this is how I've put it together with my limited knowledge.


Royce

I have a Mike Pancerny custom cue and the bottom of the pilot sets on the top of the butt "inside the joint". The wooden sides of the pilot also "touch" the inner walls of the joint.

Mike makes perfect-fitting compression joints.

 

[ideologist]

You have a small "air pocket". It may be all in our heads, but I can tell the difference in the hit and the sound.

This has been proven repeatedly to be false.

I'll try and get to Derby City with a high end cue fitted with 3 shafts, one compression fit, one not, and one flat faced. Then a couple of extra shafts of each type to help flesh out the sample size.

I will wager a fair amount of cash that no one can get all 3 types picked out. I'll make another wager that the compression fit shafts can't be picked out.

Same tip and ferrule on all shafts, same insert on all shafts aside from whether the pilot is retained or not.

 

[LGSM3]

I have a Mike Pancerny custom cue and the bottom of the pilot sets on the top of the butt "inside the joint". The wooden sides of the pilot also "touch" the inner walls of the joint.

Mike makes perfect-fitting compression joints.

this is almost physically impossible and anyone understanding tolerances would never even attempt such.

 

[HawaiianEye]

this is almost physically impossible and anyone understanding tolerances would never even attempt such.

Explain that to Mike, he made the cue. Mike attempts it, and does it.

Not only does he fill the void in the "joint", he "bottoms out" the pin in the butt and uses a glue relief hole...see the "dot" on his cues.

http://www.customcuemaker.com/

I think Mike is a little under the radar when it comes to being a custom cue maker. He has many happy customers.

http://forums.azbilliards.com/showthread.php?t=274274&highlight=pancerny

 

[Canadian cue]

If you built two identical cues, and all of the jointed parts were threaded. A joint, butt cap, ferrule, joint collar etc. Now assemble both cues but only use glue on one of them. They both would function the same but they would feel very different. To me that is the difference between a cue with compression fit at the joint and one that doesn't. But because we are only accounting for one small part of the cue the difference is very negligible. So IMO a compression fit is the glue in a threaded junction of a cue. This is what makes the flat bottomed 3/8" pins so popular IMO.

 

[tsp&b]

Well said!!!!

Skins

I really don't think this difference in opinion will ever be resolved. I also don't necessarily think that it should. I think it would be a great thing for both pool and this forum to learn to accept that others have different opinions about things. And that is OK. I respect your position. I don't necessarily agree with it, but I most certainly respect it. I also respect you for voicing it. These types of discussions are healthy for all of us as long as they remain respectful of both sides.


Royce

Very, well said!!!:thumbup:

 

[RBC]

I have a Mike Pancerny custom cue and the bottom of the pilot sets on the top of the butt "inside the joint". The wooden sides of the pilot also "touch" the inner walls of the joint.

Mike makes perfect-fitting compression joints.

Hawaiian

I have to take some exception to this. I'm sure that Mike does attempt to make both the joint face and the bottom of the pilot bottom out at the same time, but I'm not convinced that he's actually able to accomplish it.

There are so many variables involved that it's just not feasible.

Consider this. The joint faces are comprised of both wood and phenolic. The compression of those 2 materials is different, so it would be difficult to determine how much compression actually occurs when the joint is tightened. Also, the compression of the much smaller surface area of the bottom of the pilot would have to be determined as well.

In order to have equal compression of both, the smaller pilot would have to extend further and touch before the joint faces did. If it extended too far, the joint faces would not properly meet, causing more of a problem than the solution is attempting to fix. Also, keep in mind that we're dealing with wood. Wood lives in it's environment which means it will constantly change it's physical dimensions according to the ambient conditions. This alone would make it impossible to actually accomplish this feat and have it account for all the changing conditions.

The type of tolerances we're talking here, just to make it right before it leaves the shop, just aren't capable with the materials we use. I have lathes with can consistently hold .0001" tolerances in appropriate materials. a couple have resolutions in the millionths of an inch. But when cutting wood you just can't cut at those numbers.

Now, even if it did work, it wouldn't have any discernible effect on the sound waves gong up and down the cue. The amount of surface area already present is more than enough to allow that pressure wave to flow through virtually unimpeded.


I know that Mike builds a great cue, and his attention to detail is fantastic. I think it's great that he takes the time to do the things that he does, and I'm sure his customers appreciate every bit of it. I just don't necessarily agree with all the claims that others make about the benefits.

Royce

 

[ElCorazonFrio]

Now, even if it did work, it wouldn't have any discernible effect on the sound waves gong up and down the cue. The amount of surface area already present is more than enough to allow that pressure wave to flow through virtually unimpeded.



Royce

Did you even read my post about ultrasonic waves?

The wave WILL definitely be impeded because of voids. When the wave hits a void, it is reflected. This will change the rest of the waves and will change what gets transferred. It's science.

Whether or not Someone can detect these changes is another matter, don't go making things up and presenting them as facts to support your claims.

 

[HawaiianEye]

Hawaiian
I just don't necessarily agree with all the claims that others make about the benefits.

Royce

The same could be said for "supposed" LD shafts. There is NO SUCH thing as PERFECT, but that doesn't mean you can't get some things as close as possible using the machinery and materials you have and your skill.

The same goes for river bottom shafts, laminated vs non-laminated shafts, hard tips vs soft tips, steel joint vs implex joint, etc., etc., etc.

If there weren't differences in playing characteristics and preferences we'd all be still using the same house cue and you guys would all be making the same type of cues.

 

[RBC]

Did you even read my post about ultrasonic waves?

The wave WILL definitely be impeded because of voids. When the wave hits a void, it is reflected. This will change the rest of the waves and will change what gets transferred. It's science.

Whether or not Someone can detect these changes is another matter, don't go making things up and presenting them as facts to support your claims.

Frio

I just went back through the whole thread re-reading all your posts to see where I missed it. Now, I have read the post you're referring to, and I certainly don't disagree.

I think if you'll go back and reread my post you'll see that I clearly state that I'm not an engineer and this was the way I see things with my limited experience. I also stated that my position was how I personally felt. I'm sorry if you felt that I was making things up and presenting them as facts to support my claims. I don't really have any claims and I wasn't presenting anything as fact. As I said, I'm not an engineer.

I do, however, have quite a bit of experience in cues and shafts. Most likely more than most who post here. Personally, I don't think that the differences made by having a very small percentage of the total surface area replaced by the little void under the pilot is detectable, by a pool player, in the course of play. Notice that I didn't dispute your statement that it does make a difference. I just said that I don't think it makes a difference to the human who's using it. I'm sure proper equipment could detect it.

I'm not trying to push any agenda here, just share my thoughts and experience with others. Obviously, you have thoughts and experience as well. Maybe we could try to find common ground that would be good for all.


Royce

 

[RBC]

The same could be said for "supposed" LD shafts. There is NO SUCH thing as PERFECT, but that doesn't mean you can't get some things as close as possible using the machinery and materials you have and your skill.

The same goes for river bottom shafts, laminated vs non-laminated shafts, hard tips vs soft tips, steel joint vs implex joint, etc., etc., etc.

If there weren't differences in playing characteristics and preferences we'd all be still using the same house cue and you guys would all be making the same type of cues.

Hawaiian

I'm not sure I follow your logic on "supposed" LD shafts.

Are you saying that our OB shafts do not reduce cue ball squirt (deflection)? I mean, that's all that we claim that they do.

I wasn't trying to offend you. If I did, then I apologize as it was not my intention.

What I was trying to do was to share my thoughts and observations from my experiences. Some of the readers just might want to read them. If they differ from yours, well that's ok with me. I hope it's ok with you too.


Royce

 

[ElCorazonFrio]

Frio

I just went back through the whole thread re-reading all your posts to see where I missed it. Now, I have read the post you're referring to, and I certainly don't disagree.

I think if you'll go back and reread my post you'll see that I clearly state that I'm not an engineer and this was the way I see things with my limited experience. I also stated that my position was how I personally felt. I'm sorry if you felt that I was making things up and presenting them as facts to support my claims. I don't really have any claims and I wasn't presenting anything as fact. As I said, I'm not an engineer.

I do, however, have quite a bit of experience in cues and shafts. Most likely more than most who post here. Personally, I don't think that the differences made by having a very small percentage of the total surface area replaced by the little void under the pilot is detectable, by a pool player, in the course of play. Notice that I didn't dispute your statement that it does make a difference. I just said that I don't think it makes a difference to the human who's using it. I'm sure proper equipment could detect it.

I'm not trying to push any agenda here, just share my thoughts and experience with others. Obviously, you have thoughts and experience as well. Maybe we could try to find common ground that would be good for all.


Royce

Sorry about the tone of the last post.

I think we are very much on common ground. I don't really believe that anyone can tell by hit how a cue is constructed and very much doubt that voids have much effect.

My experience comes from studying wave propagation in a graduate level class.

I call out things like this because I hate misinformation.

No offense intended to you personally, I think you are an asset to this forum and to our sport.

 

[HawaiianEye]

Hawaiian

I'm not sure I follow your logic on "supposed" LD shafts.

Are you saying that our OB shafts do not reduce cue ball squirt (deflection)? I mean, that's all that we claim that they do.

I wasn't trying to offend you. If I did, then I apologize as it was not my intention.

What I was trying to do was to share my thoughts and observations from my experiences. Some of the readers just might want to read them. If they differ from yours, well that's ok with me. I hope it's ok with you too.


Royce

Royce,

You didn't offend me and neither did anyone else. I like frank discussions and I'm only sharing my thoughts too.

When I say "supposed" LD shafts, it isn't directed to anyone or any company. I'm using the term "loosely", just like a lot of the shaft makers do when they are describing the LD properties of their shafts.

There is no exact "reference" point that each shaft must meet because not every shaft is tested before they are sold. I have 30+ year old solid-maple shafts that have "as little" deflection as some of the high-dollar LD shafts.

Should EVERY shaft be labeled as to what its deflection is? I think so...especially on custom cues where the maker makes the entire cue. There should be some sort of standard where it can be reliably measured.

I am not saying that any cue or shaft "plays better" than another because that is subjective, but all cues are DIFFERENT...even another cue of the same design by the same maker.

Wood is unique.

 

[skins]

this is almost physically impossible and anyone understanding tolerances would never even attempt such.

I used to think it was normally possible as well till I tried to do it.. Two surfaces bottoming out at the exact same time with the same surface pressure.. well, I couldn't do it. Changed my thought after that....

I wonder if you put something the pilot could "seat" on that had properties of a repeatable memory spring like thingamajiggy.

I think you can do it Jake!

 

[bbb]

to all the posters
its great to read a debate and differences of opinion thread
WITHOUT A FLAME WAR
YOU GUYS ARE GREAT......:thumbup:
carry on men....:wink: