Re: Watch finishes, by CNC

Chuck,

The pattern on your example would be trivial to program longhand.
IMO, no one should attempt to use a CNC until they can program
longhand.

Doug


--- In CAD_CAM_EDM_DRO@yahoogroups.com, Chuck Knight
<chuckknight@h...> wrote:

>
>
> http://mywebpages.comcast.net/timconnor/ham922/ham922_07.jpg
>
> I want to do this type of finishing to a watch movement, just as

an

> experiment...isn't it pretty? This style of decoration is done by

using

> a rotating emery disc, and a watchmaker's lathe...lots of tedious
> handwork. I'm thinking of attaching an emery disc onto the end of

a

> dowel, and chucking it into a router. Needless to say, there is

no

> pressure involved, but only light contact and a precise and

slightly

> overlapped toolpath. Given a small, reasonably accurate CNC

router,

> this should be simple to achieve. FYI: This watch is from the

turn of

> the last century -- one with this level of decoration would cost a
> minimum of $2500, and most are closer to $4000, in today's

market. This

> one cost >$100, 100 years ago...this is one of the super-accurate
> railroad watches that kept the trains on time.
>
> Back to CNC. As I see it, once I have a tool made, it should

simply be

> a matter of programming the toolpath. Does anyone have a program

that

> would automatically generate a spiral, concentric circles,

straight

> parallel lines (cotes de geneve) and other simple "filler"

patterns

> which I could use for this purpose? I don't want to "reinvent the
> wheel" if I don't have to. I already know that the dust generated

will

> require me to clean the movement afterwards, but for the purpose

of this

> experiment, I'll happily do it. I could probably do it myself,

but I've

> never programmed in G-Code.
>
> I know there are simple "pocketing" programs floating

around...what

> types of paths do they generate?
>
> -- Chuck Knight