I need to make a size 8 rolling ring but I forgot what size to make

each of the 3 rings to come out as a size 8 when joined. Also not

sure how they interlock. I made one using size 9 rings but it was too

small. Any advice you can give would be greatly appreciated.

As a first approximation, the internal diameter of each ring is

equal to the internal diameter of the required ring, plus the

thickness of the metal used.

A size 8 has an internal diameter of 0.71". If the thickness of the

metal is.07" (you can figure the gauge - I use real measurements)

then the internal diam eter of each ring is 0.71+.07 = 0.78", which

is about size 10. Because the internal shape of a rolling ring on the

finger is a rounded triangle rather than a circle, and because they

don’t really slide on and off the finger, you can afford to make

them a little smaller than you would for a solid ring of similar

width.

Link the second ring on the first one, and the third one through

both. You can’t do it wrong.

You will need a ring mandrel with a groove in order to make each

ring round after soldering, and, with care, it’s possible enlarge

each ring a little with a roller-type ring stretcher.

Regards, Gary Wooding

It does depend on the the thickness of the bands, I remember about 1

1/2 sizes larger for 1.5 mm half rd wire, about 3mm wide.

If the target size is 8, shoot for a little under size 10 1/2 for

each individual ring. This is my protocol for 8 gauge half round.

Also be aware that a size 8 rolling ring will often fit more loosely

than a solid band size 8, due to the sliding nature of the rings.

Make sure you have a mandrel with one side ground off so you can

hammer round the last two bands without goobering up the preivious

bands.

Dale

The Silver Forge

What is rolling ring? Can someone Show me a picture. Thanks.

I presume that by “rolling ring”, you mean a russion or trinity band

of three 3 rings. I’ve been considering this problem myself recently

- I wish I had an answer, but I do have some thoughts on creating a

graph the will eventually provide the answer. The variables for this

problem aRe:* Thesection of the rings (eg. D, court, round)* The

width of the rings (eg. 2. 3mm)* The depth of the rings (eg. 1. 5mm)*

The finger size of the rings before linking* The finger size of the

rings after linking Thefinger size*after*linking is the answer we

are looking for, so we don’t need to plot that on the graph. The

section of the ring will usually be D-section, but if other sections

were needed, they would each need their own graph - if nothing else,

I suspect that the way the three bands interact would be different

depending on the section. So, we’re left with three variables to plot - width, depth and unlinked ring size. Mathematically, this is very

easy to plot - a normal XYZ graph would do; the problem is that it

isn’t very easy to look at, particularly once all possible points are

filled in. I had hoped to use a “triangular graph”, which uses the

three sides of the triangle as the three axes, but it turns out that

it can only be used in situations where the third variable is a

result of the first two the you input. My hope was to use trial and

error to plot the first few points on the graph, and then use that to

work out the rest of the datapoints - as time went by, experiments

and production pieces could be used to test the accuracy of that and

then adjust it. Each datapoint would need to appear as a finger size,

allowing the jeweller to cross-reference the known variables of the

job (width and depth) with the linked and unlinked ring sizes.

(Thinking about it, it might be better if the three axes listed the

width, depth and *linked* ring size, because I suppose that they are

the real “known” variables, and the *unlinked* ring size is the one

that we don’t have). I have two questions of my own for the

orchidians - does anyone know a suitable type of graph or table for

plotting this and does anyone know if this work has

been done by someone else (either available for free, or by

purchasing a book?). I would expect that this does exist,

because there are plenty of large companies that do production runs

of these kind of rings.

Jamie Hall - who is not scientific enough to be a scientist, but too

scientific to be a normal jeweller

http://primitive. ganoksin. com

I just tried an experiment.

I built a 3D model of a rolling ring in TurboCad. Each ring was made

from 1.5x4mm D section material with an ID of 18mm. The centre hole

(where the finger goes) is in the shape of a rounded triangle, but

the central section bulges out, rather like a rounded triangular

barrel. Measuring the outsides of the hole, the largest circle that

can be drawn inside the triangle is 13.6mm diam, but the circle that

just touches the corners is 17.5mm.

As mentioned already, the axial section of the finger hole doesn’t

have straight sides; they bulge outwards, so that the hole is bigger

on the absolute centre of the ring than at the extremities. Because

the rings slide over each other (rather like caterpillar tracks),

they don’t have to slide onto the ringer, so the assumption that the

size of the final ring is about the size of the individual rings

minus the thickness of the metal is a pretty good approximation.

IHTH

Regards, Gary Wooding

OK, lets make this a lot easier. Once you’ve made one band and

written down its length (to the 1/10 mm) before soldering and

hammering it round, you’ve got the rule for all sizes. Just add

2.5mm for a full size bump, 1.25mm for half size increments. The

thickness of the material is not a consideration, as it is the length

of the flat piece which counts - it will be the internal radius - the

outer circumference will stretch out over than mandrel when forming

the ring. This rule is for SS - 14K, yellow and white, do not stretch

as much over the mandrel; adjust lenght upwards. But the 2.5mm rule

per size still holds.

DALE - The Silver Forge