Maybe a dumb milgrain tool question?

Ron Spokovich · Apr 26, 2014

Not having used any milgrain tools before, but possibly having to do so for a jeweler who wants some scroll samples, and after having seen several videos on the matter, I have an inquiry that's never been answered. After numerous knurling jobs, I know there are specific work diameters, depending upon your knurl wheel size, that must be held so as to get the last impression to exactly meet the first one. Since the milgrain tool is, essentially, a knurling tool, how do you calculate the exact ring diameters for each size of milgrain tool wheel? Seems to me this would be of necessity so as to mesh the impressions, without flaw. Always curious about this one.

Brian Marshall · Apr 26, 2014

Simple answer - you don't.

You just "fade" out a few mm before they meet up and lightly run it up to see if they are gonna meet.

You can then fudge accordingly...

Or, what I see all the time, just run right over the join and make a mess of split beads.

Obviously, I recommend the slow, careful method described first.

Brian

One tip: Keep the tool lubricated. If you don't - you'll get half the use out of the tool... you'll wear out the pin quicker.

Plus, it may stick and make another mess if you have a tight radius to do.

monk · Apr 26, 2014

your idea of calculating will surely have you losing your mind. the wheels have differing sizes to create a specific effect or visual on the piece. each wheel leaves a slightly different appearance. i suggest you practice on scrap before commiting to an actual piece of jewelry. a good place to practice ---on old coins. they are round and a good size for getting up to speed with the technique.

rod · Apr 27, 2014

Like Brian says, re milgrain!

Re knurling ... done on a lathe, there is no need to calculate diameters and needing a ratio of tool to work. The knurling done on a lathe can be thought of as a gear cutting operation, more correctly, a gear 'swagging', a coaxing of the workpiece to be swagged into an exact repeating ration, so, as you bare into to operation, using the cross slide to force the tool deeper, you get crisp results without 'out of phase' the knurl tool pattern. Very easy to try on a piece of copper pipe.

However, beware of trying to use 'embossing' round dies with a long wavelength design. They look like knurls for working round objects, but they are used to roll out their designs onto flat sheets of silver, etc, .. no repeat is done, so no need for aligning second time around. Typically these dies would be used to roll out decorated silver strip by the mile.

Rod

Ron Spokovich · Apr 27, 2014

With all due respect and appreciation for the comments, it appears that I'll be soon purchasing some of the milgrain tools to see what happens. I know there are mathematical implications when using such tooling, and there's a difference in using one wheel and two wheel knurls. To me, I don't want to louse up a customer's job, and any flaw will stick out like a neon sign. Of course, there are ways to make this less obvious, depending upon what the particular job will allow you to do. If I work out something that would be of benefit, I'll post such on the Cafe forum.

Andrew Biggs · Apr 27, 2014

Hi Ron

Even the biggest milgrain tool is pretty small to the human eye. It's not really a matter of any kind of formula it's all about using the appropriate size for the job. Small setting, small grain, bigger settings, bigger grain, etc etc. When you come to the end just fudge the last couple of grains as Brian says. At worst you are going to be about a half a grain out and overlapping the other.........the only person that will ever know it's there will be you

Cheers
Andrew

Gemsetterchris · Apr 28, 2014

As already advised..find the right size for the job ( what runs nicely on the edge you created).
Nothing worse than seeing nice beads with burrs or marks either side.
I've sometimes ground off the outside edge of the bit holding the wheel, but it does weaken them.

Sent from my HTC Desire S using Tapatalk 2

rod · Apr 28, 2014

Ron,

A further thought, of course, have a practice on some scrap piece of copper or silver, and see if you like the results before doing the customers job? A piece of plumber's copper pipe makes a good 'dummy' ring.

Rod

Marrinan · Apr 28, 2014

IF you want to do the math portion, use the ring divider template (there is a printable one on here somewhere or I can send it to you. lay out the circumference of the ring on a flat piece of scrap then use your proportional dividers to lay out X number of segments. Next try different size mill grain wheels tell you find the one that come out line to line or you cold wrap a piece of paper around the ring and get the exact length then measure the dot size of the mill grain toll into that length and get a whole or change mill grain dot size. Or you can use the best guess method and the fudge factor at the end. Fred Just the mechanical engineering factor kicking in, Sorry

dhall · Apr 29, 2014

Also, I think I recall that the size/numbers used on beading tools correlate with the size/numbers on milgrain tools, so when you're bead setting, your individual setting beads and milgrain work can have the same size bead, if you choose the same number for each tool.

Doug

Gemsetterchris · Apr 29, 2014

dhall said:
Also, I think I recall that the size/numbers used on beading tools correlate with the size/numbers on milgrain tools, so when you're bead setting, your individual setting beads and milgrain work can have the same size bead, if you choose the same number for each tool.

Doug

Don't think they do, far as I know they go from size 00 (0.31mm) up to size 15 (0.63 mm) in 0.02mm increments.
That basically means most sizes are a total waste of time & you only need to pick 2 or 3.

Just want to add that I think people get too hung up with technical things & geometry..It's all visual work..so quit worrying & do what looks nice.

Sent from my HTC Desire S using Tapatalk 2

Southern Custom · Apr 29, 2014

"Just want to add that I think people get too hung up with technical things & geometry..It's all visual work..so quit worrying & do what looks nice."

Well stated Chris. We must strive for clean execution but in the age of microscopes we also have to remember that the human eye can only see so much when they are staring down at a ring on a finger. This is never an excuse for sloppy work of course, but minor inconsistencies are part of hand made work.
Layne

KCSteve · Apr 29, 2014

I used to do a lot of Impressionist Photography. Nothing digital, just projecting an image, distorting it, and taking a picture of the distorted image. I always tell people when they're looking at it that the fun bit is how much of what you see, you don't.

With these pictures, if you stand across the room and look at them you'll see all kinds of details that, when you move closer, simply aren't there.

With engraving we use a few lines to make a suggestion to the eyes so the brain will see what we want it to see.

As noted, this is not an excuse for sloppiness. The superfine shading so many here do so well is something your eye can't really see at any distance, but it does have an effect. Often at real world viewing distance it makes the engraving look like something 'real', which also has detail beyond what we can really see.

Maybe a dumb milgrain tool question?

Ron Spokovich

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Brian Marshall

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monk

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rod

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Ron Spokovich

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