Truer words were never spoke.
TW
Tapering. CNC vs lathe...
- Thread starter Kim Bye
- Start date
Truer words were never spoke.
TW
I will also give Todd a thumbs up on a pretty decent setup at a reasonable cost.
I just got yelled at for waking my wife up, because i was barking laughing at this response.
I had a taper shaper a long while ago the good thing about it was that it was very easy to learn to use and did a very good job its a real work horse, and it will do points as well.
Chris,
Once he establishes his tapers, why can't he remove the adjustable bar from your machine and just drop in a bar with a indexed pivot point and indicator on the other side to adjust the differential between the joint and tip size. This way he can change the tip size while hold his joint size?
His butt taper bar could also be plug and play indexed to the same pivot point. Very simple.
My friend has a deluxe and he gets very nice shaft performance production so I don't think Kim needs another machine.
I think that having a few dedicated taper bars made would save him money and give 100% repeatability without needing extra shop space.
JMO,
Rick
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That is another way that would work. Good idea.
Actually, the idea of a taper bar that pivots at the "joint" end is not really very well thought out at all.
Suppose your taper bar is set up for a "pro" taper where the last 10 inches is a straight cylinder. The premise of pivoting at the joint end (to keep the joint diameter consistent) means any size tip that varies from the original design diameter will no longer have that straight section at the business end.
For example, if the design model is based on a 13mm tip, and the customer wants a 12.5mm instead, the last 10 inches will necessarily be conical, rather than cylindrical. Alternately, if the customer wants a 13.5mm, the last 10 inches will actual flare outward - which is even LESS desirable.
Also - and a lot of newer cuemakers may not know this - slightly altering the shoulder section of a shaft can make a HUGE difference to how the shaft plays. So not only is the pivoting taper bar going to potentially change the "stroked" portion of the shaft, it's also going to change the overall action of the shaft all the way back to the joint.
No matter what your carefully designed taper happens to be, as soon as you start pivoting the taper bar at the joint end you will be altering the entire shaft profile far more than you probably would want to.
For that reason it's a bad idea, as any competent cuemaker would discover when he tried to actually put it into practice. I seriously doubt the results would suit an experienced maker who cares about the geometry of his taper(s).
TW
(PS: In anticipation of the argument that any variation in the shaft taper (caused by the silly "pivoting bar" idea) can be resolved by "sanding it out", let me point out that if this less-than-precise solution is acceptable then forget the idea of any adjustment at all, and simply sand ALL your shafts to the individual tapers you think you want.)
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Easiest solution is to learn how to work the cross slide dial.
If the cross slide has a 20TPI lead screw, it'll make working the dial easy.
One revolution=.100.
Frankly speaking, it's a must skill for re-tapering shafts .
It's not rocket science.
Won't work for curved tapers though ( like SW ).
Who wants those anyway?
If the cross slide has a 20TPI lead screw, it'll make working the dial easy.
One revolution=.100.
Frankly speaking, it's a must skill for re-tapering shafts .
It's not rocket science.
Won't work for curved tapers though ( like SW ).
Who wants those anyway?
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Really,
I have found that one taper bar with a pivot for 13mm to 12.75 works well on my pro taper and super pro tapers. If you go further than that differential between the joint size and the tip geometry at some point it will get straight and with more pivot there is actually a reversal of the taper. Not something you wish. One must understand this before he can control desired outcomes. You can't use the same pivoted bar for 13MM and pivot to 12.25, no way. That would be foolish. Tapers are tricky business and need a lot of circumspect attention to detail. If you have to sand your final taper turn to accomplish a procedure fit, you need to go back to the drawing board.
I have plotted and cut tapper bars on my CNC mill that allows me to build shafts to 11 mm while maintaining climb in the front and the correct joint dia with the use of compound tapering with engineered intermediate taper joining sections. These profiles throughout the 13mm to 11mm don't not have the appearance of a tapered shaft for 23 inches or so then gets fat very quick.
I do disagree however with your talk about sanding the shoulder or whatever it was you were saying. I believe that a good shaft taper should be compounded with an intermediate equalization taper section in the center area. This way the climb in the first 12 to 14" and the initial taper geometry from the joint to the intermediate section can be somewhat uniform on shafts with different tip sizes, never needing any sanding at the joint area. My 13mm or my 11mm shafts have the same parabolic profile look for the first 5 inches. Without sanding of any kind.
What's more is that every time a tip size is changed, the differential math to the joint is changed, you have to change or quantize the total shaft geometry. Each tip size and taper geometry is exclusive unto itself.
CNC formed shafts or CNC formed taper bars with a pivot, you still must be flying the airplane concerning performance evaluation and finish contour after the final pass on each specific size required. There is no automatic pilot here. Each specific geometry and tip size must be well planed and tested by the replete cue maker me thinks.
This is an art and the most important item effecting the way your cue performs. No one way or method is better than another. The final taper turn on each taper and tip size is exclusive to that individual shaft geometry only. As I said tapers are tricky. It took me many years to understand where the rubber meets to road.
You can build the best butt blank in the world, if you don't have shafts that perform, your an also run. The more attention paid in this area is directly proportional to overall performance.
Just my opinion,
Rick
Someone with a Chris Hightower adjustable taper bar can create the best playing taper ever made for let's say 13 mm. If he wants to do one at 12.75 he must change that set up. Buy going to a bar that will pivot and accommodate two is just one way to skin a cat.
The OP could have one taper bar made with a centered pivot. On side of the bar could be a straight line for his butt geometry and the other side could be his taper geometry for a13mm shaft. He could then adjust on the pivot giving him the option of 13mm or 12.75 in a minute or so with exacting repeatability. No need to buy a new machine and no extra shop space required. Job done !
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Rick
If you pivot off the joint end then you don't have a pro taper anymore. The straight portion will be conical
My pivots are on the tip ends Jake.
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What happens to the joint collar size?
If you're only taking down 13 to 12.75MM, there's no need to touch the taper bar.
Just fade out after 20 inches or so till you get to the 23-24" mark with the dial.
Joey,
There is a mic mounted on the joint side If you want 13mm and 850 for example you dial in a mic preset and that taper geometry is on the bar indexed off the center of the pivot.
If you want 12.75 you change the preset to accommodate that taper.
Smaller than that you need another bar for 12.50 to 12 mm and so on.
To get a 13mm shaft the differential between the tip and .850 joint is .339
A 12.75 mm is .348. After setting the mic you simply measure both ends. If it is off a hair due to indicator backlash, just adjust the bar mic a thou or two then make the next pass. Just like the Popell cooker, set it and forget it. lol
Having a taper bar template file on the computer and doing the CNC tapers is a breeze on aluminum. They physically change out in about 1 minute and can be adjusted in less time.
I prefer using taper bars and a manual machine with a gravity feed follow rest and an e stop. I can walk up to the machine, load a shaft, touch off, add ten thou engage the half nut and walk away. 30 seconds of time and I am cutting shafts. When it shuts off you are ready with the next pass in 20 seconds max.
If I built cues on a Hightower Deluxe that would be an easy way to address Kim's situation.
Rick
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I must have a different interpretation of PIVOT POINT.
If you have a stopper/hinge on the joint end, that's the pivot point for me .
If you have a stopper/hinge on the joint end, that's the pivot point for me .
Hope this helps:
No pivot on joint end:
Pivot on tip end inboard side of frame, dowel to right of small nut:
Pivot point dowel on tip end of bar out board side of frame:
Well, it's a little disconcerting to have you "disagree with [my] talk" about anything, since you obviously either didn't read what I wrote, or simply don't understand it. So, to clarify, let me just point out you are now pretty much parroting what I wrote - albeit in a more confusing manner.
The ides of using a taper bar that pivots at the very end - the joint end, according to you - is a poor solution to achieving different "tip sizes" because it will change much more about the shaft than just the tip size. This is what I wrote earlier... but I thought I should repeat it in the hope that you might actually read and/or understand it this time.
Um... "airplane"? I don't involve an airplane when I'm cutting shafts, and to be honest I don't know of any other cuemaker who does either. If you DO I would be interested in learning more about that, specifically how the plane's automatic pilot comes into play, and what the term "well planed" means.
You also lost me with your "replete cuemaker" reference. What is this particular cuemaker replete with, do you thinks?
Well, actually, the term "better" can mean many things. That the taper of a shaft is very important is quite well-known - essentially it's an important early lesson in "cuemaking 101",,, but thank you for reminding us all of that.
However, "better" can also refer to the method used to taper shafts, regarding its ease of use, or repeatability of results, or simplicity of modeling a specific profile. For those aspects of the craft, NOTHING beats CNC tapering. Forget about silly "pivoting" taper bars, or having to manually change out taper bars for different profiles - with CNC you can simply change any value you want in your G-code to produce different results. In that regard CNC is certainly easier, more accurate, and more malleable - making that method "better"... methinks.
TW
But you just recommended having a taper bar that pivots on the JOINT end. Now the pivot should be at the tip end instead?
No matter - the problem remains. A pivot anywhere on a shaft taper bar will affect the entire shaft - not just the tip or joint size. If the accuracy and repeatability of any shaft profile matters to a cuemaker he would be far better off having a distinct taper bar for each shaft size and/or design, OR use CNC (the best choice).
A pivoting taper bar for cutting shafts is simply a bad idea, unless the maker is willing to do a lot of hand sanding afterwards, and can live with the imprecise results.
TW
Roger that. Playing pivot games is death to shaft taper repeatability. Best avoided. Pivoting a bar between 12.75mm and 13mm is an obtuse approach. Set the bar for 12.75/joint diameter (happens to be my standard preference). For a 13mm tip, during final cut slowly dial in .010 once the cutter is past the stroking area but significantly before the joint area. That way both the shaft taper in stroking area and the joint area are identical with a small fudge in between. Not ideal, but about the best you can really do with a taper bar.
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Hi TW,
Pivot point on the tip side reveals a solid cutter engagement from end to end. No sanding with 100% repeatability.
Examples:
By using machine based micrometer set points to adjust the joint side of the bar up or down, the following numbers are germane.
13 mm to .850 joint to tip is a measured differential of .339
12.75 mm to .850 is .348.
I totally agree with you man, If one is having to sand any areas of the profile they have not figured it out.
Have a great weekend and be safe on the water.
Rick
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