"Bob La Londe" wrote in message
...
Alright, I have been thinking about this for a while. Most of us simple
can not afford a laser scan and CNC setup to scan a part and then just
tell the machine to make one.

How about some type of stylus setup for duplicating a part? A stylus tied
in in parrallel with the cutting point on the a mill which allows you to
trace over a part will cutting a piece of stock? Does it exist? Is it
practical? Maybe just for rough pieces?

Tracer mills were very common for core-and-cavity work (moldmaking) until
they were replaced by CNC in the late '70s. There are a few old Bridgeport
hydraulic tracers around; I think someone here had his eye on one a couple
of months ago.

It doesn't give you the accuracy of modern CNC but it's quite effective for
roughing out shapes, and even for fairly fine work that doesn't require high
absolute accuracy.

Another device that once was common was the pantograph tracer, which was
available in 2D versions for engraving work and a few 3D versions for small
cavity and relief work, mostly for making coining dies. The 2D types were
all mechanical. I don't recall how the 3D ones were set up, as I haven't
seen one for 30 years. Deckel made some really fine ones. These may still be
available on commercial routers (they were as of 10 years ago, anyway),
which are like lightly-constructed mills, for machining aluminum and wood.
Some are quite large.

You could cobble something up from the old designs, I imagine, if you really
wanted one.

--
Ed Huntress