I need to work a simple design into the surface of a 3" diameter piece
of 1/4" thick copper plate. I also need to form 1/8" copper sheet into
two different shapes; one is an elliptical cup shape and the other is
an elliptical ring. These two shapes will also have designs worked
into the outside surfaces. The only experience I have working with
copper is sweating copper pipe fittings, so I'm looking for suggestions
on how to go about this.
The material I have is C110 copper H04 (full hard) temper.
I have an oxy/acetylene rig, a Foredom TX flex shaft machine with a #30
handpiece and an assortment of burrs. I have lots of normal hand tools,
including a 4" jeweler's saw and a bunch of blades.
Let me give you a better idea of what I'm trying to make. These three
items will eventually be parts of a Japanese sword. The 3" diameter
piece will be the hand guard (tsuba), the elliptical cup shape is the
butt cap (kashira), and the elliptical ring shape is the hilt collar
(fuchi).
Here are URLs to photos that show a set of parts that are similar to
what I want to make:
Tsuba:
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Fuchi/Kashira:
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For the tsuba my original plan was to scribe the design onto the
copper, then cut it out with the saw. Then I would refine the design by
grinding, filing, sanding, and polishing. However, I have since
learned that copper can be difficult to cut and grind because it's
soft and gummy.
Some of my questions are:
1. How should I go about removing the material initially to form the
shapes? Will the flex shaft and burrs work for this, or should I try
something else?
2. How to form the ring shaped fuchi? I'd prefer not to have a
visible seam, if possible. Would it be better to machine it from a
billet?
3. How to form the cup shaped kashira? Again, I'd prefer no seam.
I thought about casting these from silver, but the last (and only) time
I did any lost wax casting was back in 1970. I don't have the
equipment for it anyway.
Any suggestions will be much appreciated.