Usign a lathe to grind lapidary materials

Here I go again designing a machine to do what I want, and I
thought, gee someone has done this before.

My current project is making candlesticks out of Texas red
agate. The desired length of the agate portion is about 7" long,
0.750 in diamater.

Too slender to do by a core drill, too difficult to get this
symmetrical and evenly ground by hand.

So, before I glom together a lathe to attach to my diamond
grinding wheel, making what the machinists would call an "outside
diameter (OD) grinder) for lapidary materials. I thought I would
ask the group if anyone has done this before, or if there even is
a commercially available machine that I can buy, rather than
build.

I don’'t mind building my own, but it always takes 4 times as
long as I think and at the end I have made a machine, not
jewelry.

Any “quick and dirty” suggestions?

Mark Zirinsky
Denver, Colorado
@Mark_Zirinsky

Hi Mark,

You might want to give Nelson the Rocky-Feller a shout - 1509 W.
6th Eugene Oregon - (541) 687-8100. He produced a multi-axis
lapidary lathe capable of preforming shapes like chess pieces. As
I recall it was fairly reasonably priced as well. I think
Contempo also produced a rock lathe called the “Sculpture” -
(818) 899-1973 (fairly old #).

Hope this helps,
Cameron Speedie
Island Gem and Rock

Hi Mark!

at the end I have made a machine, not jewelry.

Don’t I know all about that! :wink:

I think a lathe is going to be the only way to go. Of course,
you may be able to buy a gem lathe, but I don’t know if they’ll
handle 7" of material (never actually seen one).

I don’t know of any other piece of lapidary equipment that’s
feasible, other than a very large flat lap… then you’d probably
be back to freehand.

Look on the bright side… think of all the other things you
could do if you built the lathe! That’s how I always justify
these forays, and why I’m running out of room in my studio! :slight_smile:

Dave

Dave Sebaste
Sebaste Studio
Charlotte, NC (USA)
dave@sebaste.com

Hi Mark,

Sinkankas only has 4 pages on Lathe work in Gem Cutting but does
show a machine from Gryphon Corp., Burbank, California.

The basic method seems to be a very slowly rotating workpiece
(like 4rpm) with normal lapidary tools (saw, grinding wheels etc)
in the tool holder position.

If you decide to knock one up please photograph it, I am a
sucker for home made gear and turning would be really neat!

Andy Parker, Agate House Lapidary
Ulverston, Cumbria, England
http://www.netcomuk.co.uk/~andyp