How to mark out a full circle wedder
Aug 02, 2022Setting stones around a full band is simple and enjoyable work for most setters. While there are different ways to plot the stone positions, this is a quick method I use to get it exactly right the first time - very helpful when the girdles are close!
Firstly, if your stones are to be spaced far apart from each other, you can usually just set your dividers to the spacing you want, mark around the ring, and when the marks don't match just adjust your dividers and re-mark the last third of the ring. This is also good enough for most engraving patterns where you don't have to be exact.
If your spacing is tight however, the following method will ensure that your last mark always lands exactly on top of your first.
Divide the ring circumference into six equal parts
Measure the ring's outside diameter.
The diameter is 18.6mm, so the radius is 9.3mm (half)
Set your dividers to exactly half of that, then mark that spacing all the way around. This gives you six equal sections, and also gives you exact opposite points.
The radius (half the diameter) will step around the ring exactly six times
Mark out one section
Now set your dividers to your preferred stone spacing, and lightly mark out one section only. I usually do this by smearing some beeswax on the metal, sitting some stones on top to visually judge the spacing, and setting my dividers to match.
All your trial and error is done on this first section. As long as you can make this section fit a whole number of stones, or finish with ANY sixth of a stone space remaining (1/6, 2/6 etc), then by repeating that stone spacing all the way around the ring, the marks will meet at the end. Adjust the spacing as needed.
For example:
- If exactly 5 stones fit within a section, the ring will fit 30 stones (6 x 5 = 30)
- If five and a half stones fit within a section, the ring will fit 39 stones (6 x 5.5 = 33)
- If five and one-sixth stones fit within a section, the ring will fit 37 stones (6 x 5.167 = 31)
And so on.
On this ring, one section fits five and one-sixth stones.
This means I can easily continue this spacing and fit 31 stones exactly.
I do this completely by eye, by looking at the marks and thinking "that's half a stone under" or "that's five-sixths" under. If you stick to sixths, it will always multiply to a whole number by the end.
Continue the rest of the way
This stone spacing can then be continued around the ring using dividers.
Calculating the first section tells you how many stones will fit around the ring, but it's likely that your divider marks aren't perfectly accurate, and you'll start to drift off target. You can check this at the one-third and half way around marks. When you get to the half way mark, your stone marking should either be right on that spot or half a stone off. Make a tiny adjustment if needed.
The divider marks are continued around the whole ring
By the time you get back to the beginning, you should land accurately enough that no re-marking is needed.
Other people will have their own methods, but I find this way quick and accurate, and it prevents having to re-scribe the same places which can cause confusion and mistakes.
The finished bead set ring. This marking out method can be used for many setting styles.
Tips
What about using Pi?
Using pi to calculate the ring circumference will help you calculate how many stones will fit into the ring, but it doesn't help with the marking out. If you're anything like me, your divider marks are never perfect, and by the time you do 30 to 40 marks around a ring, you can be out by half a stone or more! Having six sections to use as 'milestones' helps you make adjustments when you start to drift.
What about fitted wedders?
This method only works on straight bands/surfaces than can easily be divided into equal sections. However, other shaped items can sometimes be divided into equal sections.
For example, a fitted wedder can be divided in half (left and right). The stone positions could be scribed down one side starting from the top, with the bottom point used as a milestone to determine if the dividers need to be adjusted.
Accounting for the curve
Stone setters are aware that when you set into a curved/convex surface, the stones get closer together when you seat them. This makes a negligible difference when setting small stones in most cases, but if the finger size is smaller or the stones are bigger, it starts to creep up - especially if your spacing is tight. It's not necessary to do the maths on it; it's just an issue to bear in mind if you're doing a pinky ring, pearl cap or bail.
Making corrections
The first section will often need to be scribed more than once to get it right. I like to keep my first set of marks narrow (or just dots), then scribe them wider if I have to re-do a section. That way I never get confused when drilling. In any situation where there are multiple marks and it's getting confusing, it's best to emery the marks away, or colour over the section with permanent marker before adding the final marks.
Drill between your marks!
I am a huge proponent of drilling between the divider marks, not on them. If your stones are spaced far apart it may not matter so much, but for precision work it's quicker and neater. At every stage you need to be correcting your inaccuracies, and you can't do this if your guidelines have been removed by your drill!
Drilling between the divider marks
If you're experienced with drilling on the marks and it works for you, then by all means ignore this advice. But if you're looking to improve the accuracy of your work, this is one of the first things to look at.
An important part of doing work that's both neat and profitable is to have basic procedures like this properly dialed in. By subscribing to our mailing list below, you'll hear about new setting tips as soon as they're available!
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