Question: The problem of dividing section by a divider

Kyle Jo

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Sep 6, 2019
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Thread starter #1
Hello. How's it going well?

Im in trouble in dividing section on the ring
I have a ring(diameter:: 16mm). And I want to
divide into 8 section.

So i calculated like this.
16×3.14÷8 = 6.28
and adjust my divider to 6.28 and
divided the ring. But it was so different.
It's big difference like about 5mm??

Could you guys get me to know what problem is

or
share your ways to divide the ring??

Thank you.
 
Joined
May 17, 2018
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#2
Hard to know exactly where to start without knowing if the ring is already fully formed or in a yet to be formed 'flat' state (a photo is always helpful).

Rather than dividing each segment by a certain number of millimeters, try this. Working from the outside edge of the ring, with an extra fine point permanent marker (something that is easily removed with acetone or fingernail polish remover, or just by buffing away), looking a the ring straight on from the side, carefully find the centerline of the ring, and place small point marks top and bottom exactly on the out side edge exactly at the centerline. Once the ring has been marked this way, the rest is easy. Working on the side of the ring, between each of the two marks find the exact center point, and mark to divide the ring into quadrants, then between each of those marks to divide the ring into 8ths, then between each 8th to divide the ring into 16ths. If you've done this on both sides, you should be able to then lightly draw reference lines across the surface of the ring, dividing the ring into exactly 16 equal sections.

If you're daring this will also work perfectly with a divider, but you're going to leave permanent marks (scratches) that will need to be engraved over (away) or removed with buffing.
 
Last edited:

colinskelly

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#4
Hello. I've come across this a while ago. Measuring the distance between the points of the divider will only be accurate on a flat surface because it is a straight line between the tips. That same distance travels around the circumference of the outside of the ring. The distance between the tips of the divider always remains a straight line from point to point. If you divide the ring into 2 sections, the dividers would measure the diameter of the ring (8mm in your example). It is easier to see the circumference is much longer than the diameter.

Rogers segmented circle is the easiest method I've found with minimal tools. A watch face is also something I've used to divide a ring up.
 

Big-Un

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#5
Here is a 16 segment circle. Just set your ring on the center then using a marker on the outside mark off every other segment.
Roger, I have the set of "segmented" circles like the one posted here only the entire set, divided into many different sections. When I get back home I'll try and locate it and post it. I may be off a little, but I think it was listed on this forum way back when.
 

mitch

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#6
i wrap a thin (1/8" wide) strip of white Post-It correction tape around the band, mark where the ends overlap, peel it off and stick it to my bench top. then i divide the circumference by however many sections i need, put the tape back on the band and mark the metal.
 

Big-Un

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#10
i wrap a thin (1/8" wide) strip of white Post-It correction tape around the band, mark where the ends overlap, peel it off and stick it to my bench top. then i divide the circumference by however many sections i need, put the tape back on the band and mark the metal.
That sounds way too easy! Wish I had thought of it, I tend to make things too complicated when a simple solution is there for the taking with just a little forethought.
 
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