I Bought A Round Collet Plate (but there were no instructions).

[Dennis]

As Peter explained in his thread ‘Instruction Manuals’, Many essential tools come without any helpful booklet, and unless you learned to use them as an apprentice, you will be left to fend for yourself.

Tapered collets are very attractive and will support a faceted stone without the need for a bearer. So here is one way to make them using a collet plate:

1. Select a tube with an outside diameter about 1.0mm smaller than the stone. Then try this tube into a hole about 3.0mm wider than the stone. The total length of tube needed will be twice its inserted depth. You have now established the hole to use and the length of tubing.


2. Cut off the tubing and anneal. Tubes are very vulnerable to fire scale, so you might paint it with flux, or a saturated solution of boracic acid in meths beforehand. Now place the tube over the smallest hole in the plate (to protect the tip of your punch) and inserting the punch, expand the tube gradually by tapping the punch with a hammer. Re- anneal if you feel much resistance.

3. Finally, when your collet is pretty well shaped using the punch alone, insert it into your chosen hole and wriggle the punch inside by hand to perfect it. Adjust the height to suit your stone, leaving only about 0.25mm to rub over and cut off any unwanted extension at the base. Then the collet can be mounted on a screw type mandrel and filed, sanded and polished using a Scotchbrite pad or micromesh while rotating it in your handpiece. Also by holding a file against the rotating edge it is easy to achieve a near perfect bevel.

4. To fit the collet to your ring shank, file the base with the same size round file, or abrasive paper wrapped around a mandrel.

Below:
The collet set, with a New collet and a brass rod to tap it out of the plate if it sticks.
Collet on screw mandrel using the hand piece as a lathe.
Finished ring with set CZ. Dennis

[Tabby66]

Brilliant, thank you Dennis, this kind of information is really useful! Copied and pasted into wrd to begin my 'how to use it' manual.
Thank you.

[Kwant]

Is fire scale such a big problem? I find no matter how much the silver discolours, after heating a few moments in my acid bath cleans it up with no problems, mind you I do tend to use it neat as it comes and don't dilute it.

[medusa]

dumb question, how do you fix the collet onto the mandrel?

[Dennis]

Hi Liz,

Here is the screw mandrel.You can pass the screw through the collet and tighten it. If The head of the screw turns out to be too lage, it can be reduced by the same metod, tightening it over a short piece of tubing as a spacer first. Dennis.

[Lisa Quinn]

The tip for securing the collet to the mandrel is pure genius, thank you Dennis x

[Dennis]

Is fire scale such a big problem? I find no matter how much the silver discolours, after heating a few moments in my acid bath cleans it up with no problems, mind you I do tend to use it neat as it comes and don't dilute it.

Dear Quant,
The Grey/black discolouration which appears on the surface of silver alloys when heated is largely composed of cuprous oxide and can be removed with sulphuric acid or safety pickle.

Firescale, which is cupric oxide runs deeper and is a more purple colour. It needs strong nitric acid to remove it chemically, but it can be disguised by repeated heating and normal pickling to deplete the surface copper. This effectively gives you an opaque layer of fine silver.

More commonly firescale is removed by filing and coarse abrasives. It becomes increasingly obvious as ugly patches, the more highly you polish. So for me it is not so serious a problem as I am generally content with a brushed or satin finish. See Tim McCreight, ‘The Complete Metalsmith’.
Regards, Dennis.

[Nick martin]

Thanks for reposting those images Dennis, I've found them very useful too.

Nick

[Kermit]

I've been trying to work out this Collet plate again, but not worked it out as yet.

I've attached a couple of images so you can see where I have got too.

Dennis - what is confusing me most is that it is not the same shape as in your photo's. Yours has a section of parallel tube and then the cone????

Would appreciate any suggestions.

thanks

[Tabby66]

Hi Kermit,

That is because the tube used was longer than the tapered section of the collet block, therefore the excess tube gets pushed down beyond the taper. It is the tapered part that you need to be concerned with. I've attached a few pictures of some tapered collets 'in progress'....