Shaft Tolerances

R

randomNameHere

Registered
So the other day I was bored and got thinking about tolerances of pool cue construction, and how precisely they are built (yeah, I know, I was pretty darn bored...). So in the interest of science I grabbed a digital caliper and measured the diameter of the tips on three shafts I have and decided to compare them to the sizes claimed by the manufacturer.

For those that care, my method was as follows (if you don't feel free to skip to the numbers and discussion below): Measurements were taken with a digital caliper with a precision of 0.01mm. Measurements were taken at the very base of the tip, and three measurements were taken of each shaft (between each measurement the shaft was rotated about 60 degress to account for the possibility that they might not be perfectly round) and then an average was taken of the three measurements.

Lucasi Zero Flexpoint Slim: Claimed: 11.75 Measured: 11.74
Predator Air 2: Claimed: N/A Measured: 13.63
OB Classic: Claimed: 12.75 Measured: 12.83

Note: I couldn't find a claimed tip size for the Predator Air 2 Jump Shaft.

Anyone have any idea what tolerances the big cue/shaft manufactures use for their products? I must admit I was a little surprised by the discrepancy of the OB shaft, I expected them to be closer to the claimed diameter. What do you think an acceptable tolerance is for cue/shaft production?
 
AlexandruM

AlexandruM

AzB Silver Member
Silver Member
I measured my shafts:
Z2 from Predator have exactly 11.75 mm
314/2 from Predator had exactly 12.75 mm
Joss standard shaft - 13 mm
Shaft from Lucasi L-2000JC jump cue - n/a, I measured 14 mm
 
branpureza

branpureza

Ginacue
Silver Member
Mezz cues are hands down the most precisely built cues in the industry.

randomNameHere said:
So the other day I was bored and got thinking about tolerances of pool cue construction, and how precisely they are built (yeah, I know, I was pretty darn bored...). So in the interest of science I grabbed a digital caliper and measured the diameter of the tips on three shafts I have and decided to compare them to the sizes claimed by the manufacturer.

For those that care, my method was as follows (if you don't feel free to skip to the numbers and discussion below): Measurements were taken with a digital caliper with a precision of 0.01mm. Measurements were taken at the very base of the tip, and three measurements were taken of each shaft (between each measurement the shaft was rotated about 60 degress to account for the possibility that they might not be perfectly round) and then an average was taken of the three measurements.

Lucasi Zero Flexpoint Slim: Claimed: 11.75 Measured: 11.74
Predator Air 2: Claimed: N/A Measured: 13.63
OB Classic: Claimed: 12.75 Measured: 12.83

Note: I couldn't find a claimed tip size for the Predator Air 2 Jump Shaft.

Anyone have any idea what tolerances the big cue/shaft manufactures use for their products? I must admit I was a little surprised by the discrepancy of the OB shaft, I expected them to be closer to the claimed diameter. What do you think an acceptable tolerance is for cue/shaft production?
Click to expand...
 
nobcitypool

nobcitypool

AzB Silver Member
Silver Member
OB is off by .08. Given 12.75 as the spec, they're within 0.6%. Your calipers could be off some. You could have been off some. The wood may have swollen slightly. With everything considered, for wood, I would think that is an acceptable standard. If you were dealing with metal, different story.

I guarantee you can't feel or see that difference nor could you discern the affect on the playability or feel of the shaft. I would bet OB employs modern manufacturing techniques as well as quality checks. I'm not sure you comprehend how small and insignificant .08 is for this type of product.
 
nobcitypool

nobcitypool

AzB Silver Member
Silver Member
branpureza said:
Mezz cues are hands down the most precisely built cues in the industry.
Click to expand...

Have you toured all the Manufacturers plants and examined their ISO documentation, evaluated their control charts, quality checks and measured their tooling? If not, I have no idea how you could make that claim.
 
MVPCues

MVPCues

AzB Silver Member
Silver Member
randomNameHere said:
So the other day I was bored and got thinking about tolerances of pool cue construction, and how precisely they are built (yeah, I know, I was pretty darn bored...). So in the interest of science I grabbed a digital caliper and measured the diameter of the tips on three shafts I have and decided to compare them to the sizes claimed by the manufacturer.

For those that care, my method was as follows (if you don't feel free to skip to the numbers and discussion below): Measurements were taken with a digital caliper with a precision of 0.01mm. Measurements were taken at the very base of the tip, and three measurements were taken of each shaft (between each measurement the shaft was rotated about 60 degress to account for the possibility that they might not be perfectly round) and then an average was taken of the three measurements.

Lucasi Zero Flexpoint Slim: Claimed: 11.75 Measured: 11.74
Predator Air 2: Claimed: N/A Measured: 13.63
OB Classic: Claimed: 12.75 Measured: 12.83

Note: I couldn't find a claimed tip size for the Predator Air 2 Jump Shaft.

Anyone have any idea what tolerances the big cue/shaft manufactures use for their products? I must admit I was a little surprised by the discrepancy of the OB shaft, I expected them to be closer to the claimed diameter. What do you think an acceptable tolerance is for cue/shaft production?
Click to expand...

The difference in inches between 12.75 mm and 12.83 mm is .00315. A human hair is generally around .003. I believe a shaft can easily expand/shrink a thou or two depending on environmental conditions. The accuracy for typical calipers is considered .001. The precision of your instrument might be beyond its accuracy.

By the base of the tip, are you saying you actually measuring leather? Have you ever hit a ball with it? If you have played with the shaft and are measuring the tip itself and not an untouched ferrule or shaft, then you can't make any comparisons at all, IMO.

As for the diameter of the end of the shaft itself, wooden dowel manufacturers published tolerances are often +- .003". Due to its nature, wood offers serious challenges to holding machining tolerances.
 
branpureza

branpureza

Ginacue
Silver Member
nobcitypool said:
Have you toured all the Manufacturers plants and examined their ISO documentation, evaluated their control charts, quality checks and measured their tooling? If not, I have no idea how you could make that claim.
Click to expand...



Oh ok, you got me man... I haven't been to every plant in the world.
 
Dognit

Dognit

AzB Silver Member
Silver Member
I was so bored once, I gathered all my best playing cues (Mainly Southwests) and rated the shafts by a playability index 1 thru 5. I then miked all the shafts of those cues every inch and plotted dimensions and playability, and Excel charted them thus ending up with my prefered ideal dimensions.

Now I forward this to cue makers and have my shafts tapered to spec.

It was interesting.
 
Dognit

Dognit

AzB Silver Member
Silver Member
PS if a cue maker is meeting and using ISO standards, he spends half his time on that process. Complete waste of time. I guess that would make a 4pt basic cost 5k.
 
DaveK

DaveK

Still crazy after all these years
Silver Member
MVPCues said:
The difference in inches between 12.75 mm and 12.83 mm is .00315. A human hair is generally around .003. I believe a shaft can easily expand/shrink a thou or two depending on environmental conditions.
Click to expand...

I suspect more, and should really measure (curiosity really). I find a new cue when it arrives has the shaft perfectly flush with the ferrule as if they were cut on the same pass :cool:. Normally within a few weeks the shaft has shrunk in our dry atmosphere here in the Canadian prairie desert and is no longer flush. This summer has been stupid-humid and the new cue I got a few weeks back now has a shaft larger than the ferrule :eek: (they were flush when the cue arrived).

Another anecdote, I have two shafts for my ultra-jointed Lambros, and due to seasonal swelling/shinking I have a summer shaft and a winter shaft :thumbup: The winter shaft will hardly screw on in the summer !

Dave
 
MVPCues

MVPCues

AzB Silver Member
Silver Member
DaveK said:
I suspect more, and should really measure (curiosity really). I find a new cue when it arrives has the shaft perfectly flush with the ferrule as if they were cut on the same pass :cool:. Normally within a few weeks the shaft has shrunk in our dry atmosphere here in the Canadian prairie desert and is no longer flush. This summer has been stupid-humid and the new cue I got a few weeks back now has a shaft larger than the ferrule :eek: (they were flush when the cue arrived).

Another anecdote, I have two shafts for my ultra-jointed Lambros, and due to seasonal swelling/shinking I have a summer shaft and a winter shaft :thumbup: The winter shaft will hardly screw on in the summer !

Dave
Click to expand...

Agreed. I have had shafts pass through my hands that I thought were a flush hit to the ferrule when later the wood was a larger OD. The difference was larger than I would have expected, so I would doubt my own recollections, but at least some of it is due to shaft swelling/shrinking. I was definitely conservative with the thou or two.

A local cue I built for a player has some silver rings and dot inlays in it. I can just feel a couple of them in the winter, but in the summer last time I checked I couldn't feel any of them. I almost thought he must have had it refinished, but it was original to me.
 
nobcitypool

nobcitypool

AzB Silver Member
Silver Member
Dognit said:
PS if a cue maker is meeting and using ISO standards, he spends half his time on that process. Complete waste of time. I guess that would make a 4pt basic cost 5k.
Click to expand...

Cue maker, I would agree with that. Production Cue Manufacturer ... I don't agree. Big difference between the two.
 
desi2960

desi2960

AzB Silver Member
Silver Member
randomname

i have been playing for 65 years, and that makes me an expert at nothing. BUT i would be willing to bet a quite large sum of money, that if we had 10 cues that had 12.75 shafts and 10 cues that had 12.83 shafts, i mixed them and let you shoot a rack of 15 balls with each, and after you finished each rack tell me what the diameter size of each shaft do you think you could?
 
Black-Balled

Black-Balled

AzB Silver Member
Silver Member
desi2960 said:
i have been playing for 65 years, and that makes me an expert at nothing. BUT i would be willing to bet a quite large sum of money, that if we had 10 cues that had 12.75 shafts and 10 cues that had 12.83 shafts, i mixed them and let you shoot a rack of 15 balls with each, and after you finished each rack tell me what the diameter size of each shaft do you think you could?
Click to expand...

I would bet I would get more right than wrong, if I got to shoot with each...

But if I only got to shoot with one out of the bunch? No fuggin way would I know with an certainty.
 
DaveK

DaveK

Still crazy after all these years
Silver Member
desi2960 said:
i have been playing for 65 years, and that makes me an expert at nothing. BUT i would be willing to bet a quite large sum of money, that if we had 10 cues that had 12.75 shafts and 10 cues that had 12.83 shafts, i mixed them and let you shoot a rack of 15 balls with each, and after you finished each rack tell me what the diameter size of each shaft do you think you could?
Click to expand...

I'll bet that some folks would buy a cue that has an advertised shaft size of 12.75 but would not buy one with an advertised shaft size of 12.70 saying it was too small. Funny how these things work. Regardless my interest is primarily in measuring ... what else do you do when you collect cues and precision measuring tools :cool:

Dave
 
Double-Dave

Double-Dave

Developing cue-addict
Silver Member
fastone371 said:
Are you sure about that .080"? Thats quite a difference, getting close to 1/8".
Click to expand...

The diameter is measured in mm, so is the deviation from that diameter, 0.08mm or 0.03".

I have had more shafts go thru my hands then most here and Predators are notorious for high tolerances.
I have had Z-2 shafts that were over 12mm, rarely though are the Predator shafts below the expected diameter,
most are a little over.

Mezz are always spot on with their diameters, as they are with everything.

gr. Dave
 
DaveK

DaveK

Still crazy after all these years
Silver Member
fastone371 said:
Never mind, I thought that .080 thousandths of an inch. Sorry.:confused:
Click to expand...

Anal engineer jumping in again :sorry:

".080 thousanths of an inch" = really really tiny, .00080 inches, I aint got nothing that measures that precisely

"0.080 inches" = "80 thousanths of an inch" = what you thought it was

"0.08 millimeters" is what the actual discrepacy was, and that = ~pi thousanths of an inch (3.14 thou, 0.00314 inches, as earlier noted)

"spot on" likely means "good enough" or perhaps "I can't measure that precisely so-as to notice a discrepancy", it does not mean +-0 as that is perfect and pretty much impossible to achieve :p

numbers and units and tolerances are something I always notice, and sometimes have fun with :grin-square:

Dave
 
You must log in or register to reply here.
Top