[Jewelry making - Article 00782] - Re: [Orchid] Milling Silver

[Daniel Culver]

========[ Invite a Friend - http://www.ganoksin.com/invite.htm  ]========

Richard,

    I have machined thousands of ounces of sterling, maybe tens of
    thousands of ounces, though none with CNC. Most of my experience is
    lathe and manual milling, and with larger cutters than you are using,
    so I wouldn't attempt to speculate about feed rates. I can tell you
    that your spindle speed may be too high for smooth surface finishes
    and high cutting rates even with the small cutter you are proposing.
    I know, I know that doesn't seem right. Silver or copper just don't
    cut well when the cutting temperate goes up, and for what ever reason
    flood cooling with aqueous solutions doesn't seem to work well, a lot
    of galling. I have learned to reduce spindle speed and use a micro
    drip cooler. I personally use the Trico made in Wisconsin. I could
    provide you with more about the Trico off list if you want (just a
    customer). 

    When ever possible cutting silver I use multi flute cutters and with
    your spindle speed you may want to test carbide files or nickel
    deposit diamond points. I don't know for sure, but, I suspect you
    could achieve a better finish. Still with the micro drip. Milling
    with a 1/4" four flute cutter I would use a spindle speed of 2500
    rpm and a.010" depth of cut (feed rate will need to be tested, but
    will be high) or cutting on a lathe 1/2" round piece with a single
    point cutter I would use a spindle speed of 500 rpm and a feed rate
    about.004" or.005" per rev. The harder the silver the easier it will
    machine, so when possible order hard drawn. Machining castings can
    be more difficult because of pull out any time you hit porosity. This
    is were machining with diamond points is way better. 

Good luck,
Daniel Culver
____________________________________________________________________
T h e   O r c h i d   L i s t
Open Electronic Forum for Jewelry Manufacturing Methods and Procedures
____________________________________________________________________
Orchid FAQ:
~ http://www.ganoksin.com/orchid/faq.htm
Orchid Archives:
~ http://www.ganoksin.com/orchid/archive
Orchid Galleries:
~ http://www.ganoksin.com/orchid/gallery.htm
Invite a Friend:
~ http://www.ganoksin.com/invite.htm
____________________________________________________________________
Tips From The Jeweler's Bench - Article Archive
~ http://www.ganoksin.com/borisat/tip_sear.htm
The Jeweler's Selected Bibliography List
~ http://www.ganoksin.com/jewelry-books
Buy Orchid Jewelry:
~ http://www.ganoksin.com/shop
____________________________________________________________________
-Unsubscribe:
-Email: orchid-request AT ganoksin.com Body=unsubscribe subject=blank
____________________________________________________________________