Double D, all I wanted to do was find out if a reasonable attempt was made to get them to the specified size, 42.8mm +/- .001mm diameter (1.685") and hence to a reasonable spherical condition and if you would actually take a little time to read it, you will see clearly that was my intent. See blue highlighted sections below:
Although we are waiting until the initial flurry of ordering is finished before placing our order, because we won't really need any until the spring of next year when the larger, 300 lb. flank howitzer will be done, we are a bit curious as to whether the importer's claim of one millimeter sphericity is even close. Frankly we would be extremely pleased with .002" or less.
GeorgeG, if you have a few free minutes could you go around the 3 equators at 90 deg. 135 deg and 180 deg and measure the dia. of the bisector plane in 3 places on each of those 3 planes. Nine readings on each of just 3 balls, selected at random, should give us a pretty good idea if any attempt at meeting the spec. took place during manufacture. I'm betting they are acceptable.
Mike and Tracy
You are right we have gone all over this before, but apparently you really didn't read that again either, so I will re-post those here for your convenience.
Re: Golf balls size steel balls
« Reply #89 on: November 17, 2009, 08:30:42 AM »
________________________________________
The offer Fox is making us just came in and here it is:
• Carbon steel forged balls 42.8 mm (1.685 in.)
Smooth and round – tolerance +/- 0.001 mm$1.00 each + freight
approx 80 days to produce and have them in stock.
seacoastartillery
GBO Sponsor
Site Sponsor
Trade Count: (0)
Senior Member
Offline
Gender:
Posts: 1277
Re: Golf balls size steel balls
« Reply #97 on: November 17, 2009, 02:45:06 PM »
________________________________________
Mike and I are still in for 100, and considering how much shooting we will have to do next spring and early summer to be able to come close to the results you smooth bore cannon shooters out there are getting, probably a 100 pc. re-order will necessary as well.
Well it looks like our little challenge to the steel ball maker worked out quite well. Not only did he drop the separate callout for ball form, the roundness callout, which allowed egg shaped balls to the tune of .0167", but he also tightened up the size tolerance by a factor of ten. Per Double D it is now +/- 0.001mm which translates to 1.685+/- .000039". Plus or minus 39 millionths puts these ball squarely in the precision category AND dropping the separate callout for roundness means that General Rule #1 per ANSI Y14.5M 1994, 1982, or 1973 takes over and basically says if Size only is controlled, then form, ( a single cylindrical surface, a single spherical surface and an object between two parallel planes) is also controlled within the limits specified for size alone. This is very good news for us as shooters, because a more perfect ball flies more truly to the bullseye! There is absolutely no need to thank us; we were more than happy to challenge DD's stated info from the manufacturer, in a nice way, of course.
At this time we think a debt of gratitude is owed DD for the work he has done to develop this new source of target ammo. Thanks DD! And thanks to Gary for finding them initially. Although we are waiting until the initial flurry of ordering is finished before placing our order, because we won't really need any until the spring of next year when the larger, 300 lb. flank howitzer will be done, we are a bit curious as to whether the importer's claim of one millimeter sphericity is even close.
Mike and Tracy
Here we go again.
Fox never claimed 1mm sphericity. They claimed a dimensional tolerance of .001mm
Sphericity is not a linear measurement. It is a ratio to geometric form (shape) what percentage of a form resembles a sphere a statistical value . Fox claimed with in 1% sphericity
Keep in mind that I just want to know if they are close, Double D, not perfect. As for the maroon highlight above. Which Tom, Dick or Harry every told you this. Not us. If you want, we can measure a full sample of these balls on our CMM and then we will tell you precisely if they met the spec or not; we can find out if they come within +/- .000039" of a perfect 1.685000" sphere. Bye the way they dropped the 1% sphericity per your Offer From Fox up near the top of all this, which caused General Tolerancing Rule #1 to automatically go into effect, in that the tolerance for size, ALSO controls, Form. As I explained, also above, once before, the 1% would have allowed an egg shape, because of a huge .01685" sphericity tolerance. The spec. they committed to was much, much better than that and is way, way at the top of all this.
Honest, DD, we just want to know if they made an attempt to meet the tol. that they communicated to you, that's all.
Oh, bye the way, I made an error too. In my earlier posting today, my memory was faulty and I remembered a tol. of 1 mm, actually it's 2/1000 mm total sphericity which, of course, is a very close tol.
Best regards,
Tracy and Mike