BallReviews
General Category => Drilling & Layouts => Topic started by: vg7pin on July 07, 2016, 06:36:51 PM
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Hey PSO's and drillers:
I purchased a steel span ruler from innovative with the peg on the end. I measured my favorite ball - true span, from the inside of the thumb to the inside of each finger insert.
The thumb has very little bevel.
I called in the measurements to my local PSO - made it clear this was measured from the inside of each digit. No issue.
The ball after drilling was off by 3/16 and 2/16 on each finger respectively.
I met with the operator and he remeasured and said the ball was spot on. The span ruler he uses has no peg. He said the peg throws off the measurement. He holds the span ruler slightly inside the thumb to compensate for bevel and pitch.
How do you guys measure - true span - ??
Thanks friends.
VG
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I have a span ruler with the peg. My peg is adjustable and it has to be located properly to get a proper, accurate read.
My span ruler agrees with my regular ruler that I uses, like your pro shop does. BUT it also has to be positioned correctly in order to be accurate.
More importantly, how does the drilling feel to your hand??
Also beveling has to follow your hand and the skin on it; some people have wider bases and some people have looser skin. Beveling can make these appropriately comfortable but doesn't change the actual measurement. If you add too much bevel, it can make the span feel smaller than is proper and than is comfortable; so a lot of caution needs to be exercised is adding bevel.
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Well, the ball was intended to match another ball exactly. A ball that took several attempts to perfect. Needless to say, this ball feels short.
Is there no consistency in the ball drilling universe. Four inches = Four inches 100 percent of time. Correct??
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Well, the ball was intended to match another ball exactly. A ball that took several attempts to perfect. Needless to say, this ball feels short.
Is there no consistency in the ball drilling universe. Four inches = Four inches 100 percent of time. Correct??
It should be.
Maybe the beveling is too much? That can make a span feel shorter.
If it is unacceptable to you, then the driller should fix it. How he/she fixes it is up for further discussion.
My old driller was super accurate. One time a ball just never felt right; after discussing it for a while, he remeasured and I watched. The span was off by 1/32"; it's insane to push for a correction at that tiny a length. I lived with it with no real problems. It's a shame he had to move after drilling my stuff for 25 years.
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thank you Sir
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The good news is....if the new drilling feels short and your new gauge says 3/16 and 1/8 to short, have him drill it at that much longer and see how it goes. Put that new gauge tool to work!
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How do you guys measure - true span - ??
With a Jonell Span Gauge. Allows you to measure full and cut to cut span correctly and accurately. Well worth the money.
http://innovativebowling.com/Jonell-Span-Gauge-w-1-12-Stud_p_239.html
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How do you guys measure - true span - ??
With a Jonell Span Gauge. Allows you to measure full and cut to cut span correctly and accurately. Well worth the money.
http://innovativebowling.com/Jonell-Span-Gauge-w-1-12-Stud_p_239.html
Not being a pro shop, I used this little gauge to check span. Same idea as that behind the Jonell gauge:
http://www.buddiesproshop.com/p-1650-innovative-6-inch-span-ruler.aspx (http://www.buddiesproshop.com/p-1650-innovative-6-inch-span-ruler.aspx)
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Is it off 1/8 to your middle finger and 3/16 to your ring finger?
If so, you measured total span (includes inserts) and he is measuring cut span (edge of drilled hole to edge of drilled hole).
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The PSO took out his steel ruler, with the peg sawed off, literally, and showed me how he measures. His ruler, as he held it, was spot on. My ruler, with the peg in, revealed that he was off by 1/8 plus each finger. Their was no confusion over true span or cut to cut. The specs I gave him were confirmed before drilling, the specs were true span, not cut to cut.
The PSO informed me that every operator has their own way of operating a span gauge.
I just think this is BS. I have purchased a dozen balls on line, they always come back as I expected, every time. Because I wanted to experiment with a span change, I had the local guy plug many balls. Then after finally deciding on the "winning span" the final specs were texted to him, and you know the results.
It just amazes me that someone can measure a span and get a different numeric result than the next operator. If I know my specs, a ball drilled by shops across the country should come back within a 1/32 at least. 1/8th is hard to accept.
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Since he measures differently it would make sense to have him measure the ball with the span you want and see what he comes up with.
If cut to cut is correct, then it comes down to the inserts and possible thumb insert differences.
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If he's off by different amounts to each finger and you are both talking about the same thing then he probably missed and is holding the ruler back to make it read the correct measurement, so it doesn't look like he missed.
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You need to make sure that you are measuring to the center of the thumb hole. Do not hold the span off to the side a little. That will happen easily if you do mark the top center edge of the thumb hole.
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You need to make sure that you are measuring to the center of the thumb hole.
Measure to the center of the thumb hole??? might want to re phrase that part.
The true span is measured from gripping edge to gripping edge, not the center of the holes.
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So look,
I am a house bowler - league only. Average is from 195 to 210 (on a good year).
I don't drill my own stuff, but I buy more balls per year than the average bowler. Its a hobby to me. I enjoy reading about layouts, new equipment, dual angles, double thumbs, etc etc. I can layout my own gear. But really. You have to draw the lines to hit the lines.
The PSO's nightmare??
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You need to make sure that you are measuring to the center of the thumb hole.
Measure to the center of the thumb hole??? might want to re phrase that part.
The true span is measured from gripping edge to gripping edge, not the center of the holes.
If it is needed to be said that it is the center edge then you should not be doing the measuring it, JMO.
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IMO, you should have different people use the EXACT SAME tool to do the measuring. I say this due to my experience with enormous differences in the quality of the measuring tools themselves.
On tape measures used for basic carpentry, I have seen guys measure off 5 feet using one brand of measure, and then repeat it using another brand and discover the ending difference between the two was approximately 3/16".
Same thing in the science industry, the old lab I used to work in was restricted to using only one brand of measuring instruments because of inconsistent results using multiple brands.
Hope this helps.
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That makes some sense but, if someone sends out a spec sheet to be used to drill, then you would have to send them the measuring instrument also to perform the task.
We need a universal measuring tool!! That's IT!!
Thanks for all the responses - have a great weekend!
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If it is needed to be said that it is the center edge then you should not be doing the measuring it, JMO.
That is the problem with a lot of technical writers, small little details get left out or are not properly phrased because they assume it should be obvious to the reader. JMO
and it was just a suggestion.
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If he is measuring to cut to cut then I would say using a ruler without a peg might be ok. If you are going full span, I don't see how you could say you were holding the ruler at the exact edge of a thumb hole, especially if it has a lot of bevel.
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1/8 and 3/16 is more than ruler error. I would ask that it is fixed. If refused, I'd move op n to a new driller capable of hitting a span... that simple