Re: Accuracy in Jewelry - To Terry Ackland

Bill,

Accuracy is a relative term in cnc machining. But, if you are able
to do work to your needed accuracy on a converted Taig mill then I
would say that is not what would be considered high accuracy in the
commercial machining field. What tolerances can you hold on your
machine? How high rpm is your spindle?

Doug


--- In CAD_CAM_EDM_DRO@egroups.com, William Reidsema <wreidsema@y...>
wrote:

> Hi,
> I'm one of the new lurkers on the group. Terry asked
> why accuracy is important for an artistic craft such
> as jewelry. Well, let me tell you since I routinely
> make several jewelry articles a week with my desktop
> mill. And I hand carved everything for years!
> Imagine a ring with 37 stone seats ranging from 1 mm
> to 2.5 mm diameter with a depth of 1.7 mm. Each stone
> seat has four tiny pinpoint prongs that are .4 mm dia.
> and 1.2 mm high. This ring was made on my mill while I
> worked on other things. One finished, the stones were
> very easy to set, thanks to the accuracy of milling.
> Or imagine a coat of arms ring where the design is
> incised in a ring top at about .7 mm deep with the
> name about 1 mm high lettering raised .4 mm. I do
> these coats of arms rings routinely and accuracy is
> everything!
> I am presently retrofitting my little Taig mill
> with 180oz steppers and Gecko drives on all four axes.
> I expect even greater accuracy with the microstepping
> and, at the very least, the bigger stepper on the Z
> axis won't have as much strain as the old 111 oz
> stepper did pulling the Z axis motor and spindle up.
> Some of the organic looking jewelry I design is
> entirely built up by hand but having been a jeweler
> for
> some 35 years, I can tell you that CNC has made a
> great difference in my life and I love the learning
> process necessary in CNC!
> Bill Reidsema