Tapered not flat or piloted joints.
- Thread starter JLR
- Start date
JLR, you mean like conical/convex joint like Lambros and Layani?
ink
Ok guys,
Please read and understand that I am not knocking, just making a good solid statement about the tapered fit of joints.
I have checked several cue joints that you guys speak off. None, I mean, "NONE" have been as good a fit as they should be or as the guys claim.
What it amounts to is you have an outside cone going into the inside of another cone, [male female],with a fitted joint pin, and insert. To many parts to machine perferctly.....Don't believe me, try it...
Testing these, I used "pressing blue" [a tool and die makers ink], it's "tattle, tail", ink that shows how good the fit of the two parts are. You either use a spray can of ink or brush it on one part, put the parts together, and then un-do the parts. The wipe-off [removal of the blue ink from rubbing the other part], shows how well the two machined parts fit.
100% wipe off would be great, but this has never been the case in my testing, more like 30 to 40% wipe off, at best. Not a good solid fit.
You got to be a hell of a machinest and you must have the proper equipment to do such close work.
For the best fit, the parts should be ground. Single point machining, [in my opinion], is useless for this. Only grinding can get it that close and smooth for a real good fit.
Maybe, Murry, expand on this subject. He owns a "big" machine shop.
Let us hear from you Murry?
blud
JoeyInCali said:
Ok guys,
Please read and understand that I am not knocking, just making a good solid statement about the tapered fit of joints.
I have checked several cue joints that you guys speak off. None, I mean, "NONE" have been as good a fit as they should be or as the guys claim.
What it amounts to is you have an outside cone going into the inside of another cone, [male female],with a fitted joint pin, and insert. To many parts to machine perferctly.....Don't believe me, try it...
Testing these, I used "pressing blue" [a tool and die makers ink], it's "tattle, tail", ink that shows how good the fit of the two parts are. You either use a spray can of ink or brush it on one part, put the parts together, and then un-do the parts. The wipe-off [removal of the blue ink from rubbing the other part], shows how well the two machined parts fit.
100% wipe off would be great, but this has never been the case in my testing, more like 30 to 40% wipe off, at best. Not a good solid fit.
You got to be a hell of a machinest and you must have the proper equipment to do such close work.
For the best fit, the parts should be ground. Single point machining, [in my opinion], is useless for this. Only grinding can get it that close and smooth for a real good fit.
Maybe, Murry, expand on this subject. He owns a "big" machine shop.
Let us hear from you Murry?
blud
Blud, have you ever done this test on a normal flat joint? For comparison, what are typical results of blue dye transfer in that case? Wouldn't you also get much better transfer results in a flat joint if you ground it?
Although, with a tapered joint, you would have to use the compound rest for the cut which does not have a power feed. On a flat joint, you can use the power feed on the cross-slide, getting a much better finish than turning the handwheel by hand.
I would think in the case of a tapered joint, getting the angles of the shaft and the butt exactly correct would be much more important than whether a single point tool or a grinding wheel was used for the finish cut. I have not attempted this joint, but if I were to do it this is what I would do... Put a precision machined bar in the chuck/collet. Then hold an angle block against this bar. Then put an indicator in the tool holder and sweep the surface of the angle block until the compound is exactly at the right angle. It would probably be worthwhile to permanently attach the angle block to the bar so you wouldn't have to hold the angle block while sweeping the surface. You would also have to make sure the top of the angle block is parallel to the ways of the lathe. Otherwise, the angle would be wrong.
Nick
Although, with a tapered joint, you would have to use the compound rest for the cut which does not have a power feed. On a flat joint, you can use the power feed on the cross-slide, getting a much better finish than turning the handwheel by hand.
I would think in the case of a tapered joint, getting the angles of the shaft and the butt exactly correct would be much more important than whether a single point tool or a grinding wheel was used for the finish cut. I have not attempted this joint, but if I were to do it this is what I would do... Put a precision machined bar in the chuck/collet. Then hold an angle block against this bar. Then put an indicator in the tool holder and sweep the surface of the angle block until the compound is exactly at the right angle. It would probably be worthwhile to permanently attach the angle block to the bar so you wouldn't have to hold the angle block while sweeping the surface. You would also have to make sure the top of the angle block is parallel to the ways of the lathe. Otherwise, the angle would be wrong.
Nick
[I would think in the case of a tapered joint, getting the angles of the shaft and the butt exactly correct would be much more important than whether a single point tool or a grinding wheel was used for the finish cut. I have not attempted this joint, but if I were to do it this is what I would do... Put a precision machined bar in the chuck/collet. Then hold an angle block against this bar. Then put an indicator in the tool holder and sweep the surface of the angle block until the compound is exactly at the right angle. It would probably be worthwhile to permanently attach the angle block to the bar so you wouldn't have to hold the angle block while sweeping the surface. You would also have to make sure the top of the angle block is parallel to the ways of the lathe. Otherwise, the angle would be wrong.
Nick[/QUOTE]
Nick, what your doing in either case is getting the angle right. Single point is in no way as smooth as a grinding wheel.
The set up your talking about will work. I, would use a tapered reem for the shafts angle. After your done with the shaft, place the reem in your jaws, and get your new angle from the side of it.
Maybe a better way, but this worked well for me.
Problem with this type of joint system, is you got to get the dia.,of the taper, just the right size, so the shoulder of the shaft [base] fits down and fits the taper at the same time, and the pins pilot lines up also.
Murry, may have a better idea.
If I were to have this type of a joint, it would only touch at the top and bottom of the tapers, meaning that between the top and bottom, it would be relived by maybe .010 in the midle of it. Top shoulder of the taper fits, and the bottom , bottoms out at the same time and fits snug.
Hope I didn't loose you here.
Flat faces do match up good if machined properly and they have a little relife at the base of the pin, [chamffered] at the bored hole on both the shaft and the cues face.
I used the pressing blue on many joint pins years back, and didn't like the results, or rub-off, so I developed my own pin. It's got 90% wipe off.
works for me.
blud
Nick[/QUOTE]
Nick, what your doing in either case is getting the angle right. Single point is in no way as smooth as a grinding wheel.
The set up your talking about will work. I, would use a tapered reem for the shafts angle. After your done with the shaft, place the reem in your jaws, and get your new angle from the side of it.
Maybe a better way, but this worked well for me.
Problem with this type of joint system, is you got to get the dia.,of the taper, just the right size, so the shoulder of the shaft [base] fits down and fits the taper at the same time, and the pins pilot lines up also.
Murry, may have a better idea.
If I were to have this type of a joint, it would only touch at the top and bottom of the tapers, meaning that between the top and bottom, it would be relived by maybe .010 in the midle of it. Top shoulder of the taper fits, and the bottom , bottoms out at the same time and fits snug.
Hope I didn't loose you here.
Flat faces do match up good if machined properly and they have a little relife at the base of the pin, [chamffered] at the bored hole on both the shaft and the cues face.
I used the pressing blue on many joint pins years back, and didn't like the results, or rub-off, so I developed my own pin. It's got 90% wipe off.
works for me.
blud
I forgot the part about the diameters having to be just right, as you mentioned Blud. I understood what you meant about only touching on the top and bottom. Many morse tapers are that way. On the other hand, many make contact for their full length. Although I don't think I'll personally have a joint like this, I have enjoyed this discussion. Thanks for the information.
Nick
Nick
Looking at Layani joints, for reference, I would think that the cone section on the shaft, a plastic of some sort, would have to be of necessary durometer to compress just enough with appropriate pressure to both make sufficient contact and to close the face of the joints. I believe this could be done easily enough and without grinding. At least on metalworking equipment with the correct tooling you can attain finishes which are flat enough that auto companies don't grind most bearing surfaces. Mr. Bludworth and the rest of you guys-Do you think perfecting this joint would be worth it or would it simply be another joint design? Out of place but I'm already typing so another question. Mr. Bludworth, I read your comments on the McDermott shafts with the composite cores. Do you think they are simply using shafts from Easton arrows as the core? If not, do you think it would be worth playing around with this idea? It would be very difficult for the layperson to drill a hole in the shaft this small for that length with modest equipment, but using say 2 halves or 4 quarters and maching gooves then laminating over the arrow shaft would very easy. What do you think? Get used to me guys cause I can't get enough of your wisdom and knowledge. Thanks in advance.
blud said:
Todays ridgid machines and modern tooling have replaced the grinder in a lot of applications. Problem is the tools that cut metal well don't cut wood worth a poo. I'll have to think on how I would do it on a cue.
The problem with cutting a perfect taper for a pool cue joint is that it won't come apart. Think about a Morse taper or a Jacobs taper (which holds the chuck on your drill press). A easy tap and they are together. Geting them apart takes a wedge and a good swat. Not exactly practical for a joint. I'm sure layani did a good bit of research to make a taper that gave him the performance that he wanted and would still come apart.
To JLR- The Layani joint is phenolic and does not "give". There is a slight gap between the shaft and the joint collar when it is assembled.
Which begs a question.Murray Tucker said:
Why go to all this trouble to a joint that involves even more phenolic?
If one designs a convex/concave joint to have more wood contact but in the end adds more phenolic, is defeating the purpose imo.
Since I'm directly concerned by this thread I might as well throw in my little knowledge of the matter. First of all, I'd like to thanks Blud for recognizing the difficulties inherent to making such a joint. It's the first time I hear it coming from a cuemaker. I know that you always try to distinguish those who seek always further from those who are into cuemaking "for the money", and I'll tell you making a joint like this (with all the set up time it requires and all the years we've spent developping it) is indeed not very profitable financially. But it is what we do and what we believe in and also what distinguishes the hit of our cues. The "blue test" you referred to is indeed a good test that we consistently make on our joint to verify the fit. At first we were getting a 65-70% fit which is considered very good for a conical joint (the total surface being already higher than a flat face). Considering we had about 2000$ worth of machinery(Canadian that is!) we were having fairly good results. But in the last years my partner (who is quite exceptionnal at achieving a lot with not much) came up with a way of machining the joint with a 90-95% fit. We made the testings through a company that analyses the shapes with lasers to come up with a more precise results than the "blue test".
Of course, as Murray said, we calculated the angle of the cones so that they won't stick together (although sometimes the joint can be hard to take apart). Theoretically speaking you need to have equal or less force radially than axially. If the radial forces are higher than the joint will simply stick together. Actually the first conical joint we built was self locking. The angle of the joint was steeper so that the two cones would simply stick together. The only problem we had was that a miscue would cause the two parts to separate. So my partner came up with the idea of reducing the angle and adding a small pin just to hold the two cones together. But the pin actually serves no other purpose since there is no tension applied on it when the cones are sitting on one another. As far as the material goes, we did make some testing with other types of material but the results were very similar. In other words with this type of joint configuration, the material does not have a significant influence on the hit. Since the fit has to be more than very precise, we use materials that are very stable, hence the phenolic male cone and the stainless female cone. The idea of recreating a purely wood feel with a wood to wood joint is in my honest opinion more of a myth than anything else. While the wood to wood joint provides a certain feel, in no way is it similar to a one piece wooden cue. Putting two pieces of wood together does not recreate the internal structure of the wood cells, which means the 2 pieces of wood are in discontinuity with each other, and this discontinuity cannot be artificially overcome by simply screwing them on one another. What our joints wants to do is precisely to eliminate any interaction at the surfaces that would alter the continuity of the vibration. Although I do not know for a fact if it does what we think it does, one thing I know is that it provides a kind of feedback that no other types of joint provide. Also note that we use this type of joint to join the forearm to the handle, but the gap is hidden under the linen (or leather). Now to be able to judge if that joint is better or not on a pool cue is something I cannot do, only the player can judge by himself if he likes this type of hit.
I wish what I'm trying to explain is clear as my english doesn't get better than this. Hopefully my partner will be able to provide me with some technical datas in english if you want to know more about the way he does machine the joint. As far as improving this joint, we've thought of many things but nothing better than what we've come up with as of now.
One last thing for the upcoming cuemakers. When you have the knowledge, the intelligence and the creativity to be able to innovate and build things that seemed at first too complex to be worth it or simply impossible, than you know that you will be able to do the small things with a precision unparalleled. I do think my partner is achieving right now things that seemed "impossible" at first especially with the type of machinery we had. This is when natural intuition and ingeniosity comes in. That's why he has my admiration, as well as all cuemakers that are geniuses in their ways.
Thierry Layani
www.layanicues.com
Of course, as Murray said, we calculated the angle of the cones so that they won't stick together (although sometimes the joint can be hard to take apart). Theoretically speaking you need to have equal or less force radially than axially. If the radial forces are higher than the joint will simply stick together. Actually the first conical joint we built was self locking. The angle of the joint was steeper so that the two cones would simply stick together. The only problem we had was that a miscue would cause the two parts to separate. So my partner came up with the idea of reducing the angle and adding a small pin just to hold the two cones together. But the pin actually serves no other purpose since there is no tension applied on it when the cones are sitting on one another. As far as the material goes, we did make some testing with other types of material but the results were very similar. In other words with this type of joint configuration, the material does not have a significant influence on the hit. Since the fit has to be more than very precise, we use materials that are very stable, hence the phenolic male cone and the stainless female cone. The idea of recreating a purely wood feel with a wood to wood joint is in my honest opinion more of a myth than anything else. While the wood to wood joint provides a certain feel, in no way is it similar to a one piece wooden cue. Putting two pieces of wood together does not recreate the internal structure of the wood cells, which means the 2 pieces of wood are in discontinuity with each other, and this discontinuity cannot be artificially overcome by simply screwing them on one another. What our joints wants to do is precisely to eliminate any interaction at the surfaces that would alter the continuity of the vibration. Although I do not know for a fact if it does what we think it does, one thing I know is that it provides a kind of feedback that no other types of joint provide. Also note that we use this type of joint to join the forearm to the handle, but the gap is hidden under the linen (or leather). Now to be able to judge if that joint is better or not on a pool cue is something I cannot do, only the player can judge by himself if he likes this type of hit.
I wish what I'm trying to explain is clear as my english doesn't get better than this. Hopefully my partner will be able to provide me with some technical datas in english if you want to know more about the way he does machine the joint. As far as improving this joint, we've thought of many things but nothing better than what we've come up with as of now.
One last thing for the upcoming cuemakers. When you have the knowledge, the intelligence and the creativity to be able to innovate and build things that seemed at first too complex to be worth it or simply impossible, than you know that you will be able to do the small things with a precision unparalleled. I do think my partner is achieving right now things that seemed "impossible" at first especially with the type of machinery we had. This is when natural intuition and ingeniosity comes in. That's why he has my admiration, as well as all cuemakers that are geniuses in their ways.
Thierry Layani
www.layanicues.com
Thierry Layani said:
Thierry,
Thanks, that was a very informative post. I think your joint is not right or wrong, but merely one more option for the consumers. For english as a second language, you do very well. I would not have guessed. As to your partner, how are duties shared? Or in other words which tasks do each of you perform? What is his name?
Tracy
My partner's name is Alain Gendron. He started making cues in 1989 but was only doing it as a hobby until we started together "Layani cues" in 2000. He's actually the one who wanted the company to have my name but it should have been the other way around. Right now I'm mostly in charged of designing the inlays and doing all the inlay work. My main job is in a totally different field, I work as a philosophy professor in a College. My partner works full time on the cues though.
Thierry Layani
Thierry Layani
Thierry Layani said:
So you are free of many technical hassels, thereby free to concentrate on your art. That sounds like a good arrangement.
I looked at your website, your designs are very nice.Tracy
Thierry Layani said:
Wow..philosophy professor...I've heard of cuemakers with interesting day jobs, but most of them are in the machining/lumber/musical instrument industries. Oh yeah, and not forgetting NASA (Jim Buss). Theirry, which school of philosophy thought do you teach?
Btw, It's Eddie here..
I mostly teach ancient greek philosophy as an introductory course, but my major was in philosophy of religion and 19th century philosophy. It is indeed a different line of thought than cuemaking, but in a way both seek perfection through their own mean, that's what I like about cuemaking.
Thierry
~~Hi Eddy!~~
Thierry
~~Hi Eddy!~~