what exactly is the middle hole for, go-no go gages only require extremes of the tolerance, so the middle hole only adds expense,and no purpose,,,,,lexan probably would have been a better material.
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Anyone make go/no-go ball gauges?
- Thread starter derangedhermit
- Start date
Maybe a few more players and owners would care if they could see for themselves the status quo. I'm not trying to start a movement.:grin:It's been my experience the with 3C balls played on a public table that's kept clean but the balls see 2-3 hours of play per day they will wear down about .5mm (.01968") in less than 1 year and its time to consider a new set.
My set which maybe has 15 games on a public table the past year measure 61.3mm, down .2mm measured off my calibrated Starrett Dial Caliper.
I'd say with public tables the balls need to be pitched after 6 months since most tables rarely get cleaned.
Your gage is a nice idea but if the room owners cared about that they'd already be taking care of their tables. But maybe only 1 in 25 customers would notice and appreciate the effort.
I think the test result will be that, in US pocket billiard rooms, very many (most?) cue balls will drop through the smallest hole, next smallest are the 1-9 from 9-ball play, and the largest, keeping their size the longest, maybe twice or three times as long as 1-9 in some rooms, are the 10-15.
"my calibrated Starrett Dial Caliper" - :bow-down:
At one point I was thinking 11 holes:grin:. You're right, the middle-size hole is optional and adds cost - maybe it should go away.what exactly is the middle hole for, go-no go gages only require extremes of the tolerance, so the middle hole only adds expense,and no purpose,,,,,lexan probably would have been a better material.
Why would Lexan (polycarbonate) be better? :scratchhead: I'm all ears. I'm concerned about wear rate.
Lexan is tough as hell, won't crease like thin aluminum, won't scratch up my Centenials:thumbup:, almost unbreakable, available at most hardware- home supply stores, and not terribly expensive.
As far as,,,,"calibrated Starret Calipers",,,,,,right!
Calibrated just means it read what it was supposed to when it was calibrated, it don't make it measure any more accurately.
FTR,,,,,any,,,,yes any,,,,precision measuring tool can only be as accurate as 2 of the smallest measure increments on that tool. Therefore a tool such as a caliper, graduated in .001" increments, can only reliably measure to an accuracy of .002".
As far as,,,,"calibrated Starret Calipers",,,,,,right!
Calibrated just means it read what it was supposed to when it was calibrated, it don't make it measure any more accurately.
FTR,,,,,any,,,,yes any,,,,precision measuring tool can only be as accurate as 2 of the smallest measure increments on that tool. Therefore a tool such as a caliper, graduated in .001" increments, can only reliably measure to an accuracy of .002".
Update and some results and conclusions
I got my estimate back from a metal shop, and in the meantime I've measured about 100 balls at a local room with a digital caliper. I have yet to find a single ball large enough to meet the minimum tournament size (2.245"). All were in the 2.150"-2.240" range.
I weighed them too. The density stays the same across balls - smaller ones weigh the appropriate amount less than larger ones, as near as I can measure.
The 2.15" ball is only 4-5% smaller than a regulation 2.25" ball. But if that 2.25" ball weighs 6 oz, the 2.15" ball only weighs 5.05 oz!* I think that much difference in weight makes a real difference in play. The big difference in weight is because weight is proportional to the cube of the diameter, so as the diameter changes a little, the weight changes a lot.
*An approximation is that for each 1% smaller in diameter, the ball will weigh 3% less. If my math is wrong, I hope someone corrects it.
And, as was suggested, I did find one set, but only one set, where the balls weren't nice and round. This set had humps where the number circles were. The humps were easily felt. I don't know how much they would affect play, but not much I think - I noticed no issues when playing about 3 hours with them. Certainly no thumping or bouncing as they rolled over the numbers - I tried that.
The several cue balls I measured were smaller and weighed less on average than the other balls. The room needs to replace the cue balls more often.
And now I know why my Magic Rack wouldn't always get the balls touching, and it's not the fault of the Magic Rack.
My education in the real world of pool room billiard balls continues.
I got my estimate back from a metal shop, and in the meantime I've measured about 100 balls at a local room with a digital caliper. I have yet to find a single ball large enough to meet the minimum tournament size (2.245"). All were in the 2.150"-2.240" range.
I weighed them too. The density stays the same across balls - smaller ones weigh the appropriate amount less than larger ones, as near as I can measure.
The 2.15" ball is only 4-5% smaller than a regulation 2.25" ball. But if that 2.25" ball weighs 6 oz, the 2.15" ball only weighs 5.05 oz!* I think that much difference in weight makes a real difference in play. The big difference in weight is because weight is proportional to the cube of the diameter, so as the diameter changes a little, the weight changes a lot.
*An approximation is that for each 1% smaller in diameter, the ball will weigh 3% less. If my math is wrong, I hope someone corrects it.
And, as was suggested, I did find one set, but only one set, where the balls weren't nice and round. This set had humps where the number circles were. The humps were easily felt. I don't know how much they would affect play, but not much I think - I noticed no issues when playing about 3 hours with them. Certainly no thumping or bouncing as they rolled over the numbers - I tried that.
The several cue balls I measured were smaller and weighed less on average than the other balls. The room needs to replace the cue balls more often.
And now I know why my Magic Rack wouldn't always get the balls touching, and it's not the fault of the Magic Rack.
My education in the real world of pool room billiard balls continues.
Last edited:
I bought a set of Aramith Tournament balls, and measured and weighed them. They all measured between 2.2495"-2.252" and weighed between 5.80 and 5.85 oz. (My scale displays to the hundredth of an ounce.)
I re-measured and re-weighed a few balls and if there are errors, they are repeatable. I'm a little surprised there is as much as 0.0025" difference in diameter. There were three balls that were 2.252", one of them the cue ball (black symbol) at 5.85 oz. The rest were between 2.2495"-2.251".
We enjoyed playing with them tonight. I'm now pretty confident that all the balls provided by the room are undersized due to wear, with some noticeable mismatches in weight.
I re-measured and re-weighed a few balls and if there are errors, they are repeatable. I'm a little surprised there is as much as 0.0025" difference in diameter. There were three balls that were 2.252", one of them the cue ball (black symbol) at 5.85 oz. The rest were between 2.2495"-2.251".
We enjoyed playing with them tonight. I'm now pretty confident that all the balls provided by the room are undersized due to wear, with some noticeable mismatches in weight.