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This list digest contains the following message subjects:

1. LapDigest News for Issue No. 155 - Sat 7/11/98
2. SPHERES: Sphere Making: One Guy's Method
3. SPHERES: Commercial Sphere Machines
4. SPHERES: Clason Brothers and Their Machines
5. SPHERES: Where to Buy Used Sphere Machines
6. SPHERES: About Sphere Making
7. SPHERES: Some Comments


Subject: LapDigest News for Issue No. 155 - Sat 7/11/98

I am pleased to present the first of two issues devoted to the
art of Sphere Making. The second issue will be published about
three issues from now. And I want to thank John Duncan and
John Blue for the two major articles on this subject.

Sphere making must be a lonely part of the lapidary arts;
there are only a few (relatively speaking) people doing it,
and there is not much published on it. I hope all of you will
enjoy these two issues, and that those making spheres will use
the LD to further communications between yourselves.

The contents of the second issue, appear, at this time, to be:

1. Sphere Making on a 3-Head Small Machine
2. Where To Get Motors for Sphere Machines
3. Bibliography on Sphere Making
4. Sphere Making Notes
5. Some Comments
6. Sphere Maker's List
7. Sphere Maker's List
8. Sphere Making Machines

If you have further contributions to this topic, please send
them is soon and I will put them in the second issue.

Have a great summer!


Subject: SPHERES: Sphere Making: One Guy's Method

by: John Duncan

Every sphere maker has developed particular methods and tools
that work for him or her. Machines, grinding cups, polishing
methods, grit feeders, etc. vary widely. I will provide some
background information and describe my methods as developed
over 25 years of off-and-on sphere making. Some of the
machines and gadgets are difficult to describe without
sketches. I will try my best to make them clear.


There are three basic machines, a manual arrangement such as
used by Paul Brost, as a retired farmer in North Dakota, a
two-headed machine and a three-headed machine. Perhaps a
four headed machine is theoretically possible!

All sphere machines press rotating cups against a roughly
rounded rock preform while applying grinding grit and water
to the rock. The preform moves in a random pattern, grinding
off high spots. The grit slowly wears away the rock (and the
cup!) until the rock is perfectly spherical.

Paul Brost used a piece of pipe rotating about a vertical axis
on a thrust bearing. After roughing out a sphere with saw and
grinding wheel, he placed the preform on the pipe and manually
pressed another piece of pipe against it as the preform
rotated. He added grit and water as needed and went through a
series of finer grits and polish. He made a large number of
spheres, which are exhibited in a museum in Parshall, North
Dakota. While this works, it is far too time consuming for

A two headed machine has two gear motors driving cups
approximately horizontally against the preformed rock. Typical
of these is the machine sold by Covington Engineering Corp.,
715 W. Colton Ave., Redlands, CA 92373. These are sturdy
machines and will do a good job. However they are slower than
a three headed machine and there is a greater chance that the
rock preform will stick in one position, which is not good.
If you are not around to fiddle with the machine to get proper
random motion, you will soon have two nice round grooves in
the preform. Some people mount a dowel or the like, pressing
against the side of the rock to provide offset friction and
encourage random motion.

In general, the three headed machine gives superior
performance. There are two basic types of three headed
machine. One hinges three metal plates to a base in a circle
so that they all pivot toward a central axis. Gear motors
are fastened near the tops of the plates so that their shafts
more or less meet when the plates are pivoted together. Cups
are mounted on the shafts and the rough rock preform is placed
between the cups. Water and grit are fed to the top of the
preform. (More about grit feeders later.) A "screen door"
type spring or large rubber band is usually wrapped around the
top edges of the plates, biasing them toward the center point.
These are easy to build and are very effective. I recommend
this type to any new sphere maker.

Richardson’s Recreational Ranch, Gateway Route 440, Madras,
OR, 97741, 1-800-433-2680, sells an excellent machine of this
type. They also have a sphere factory going and have a number
of fee areas for digging thundereggs and other material.
Also, free camping and a great rock shop! VERY friendly
people. They will patiently answer sphere making questions.
One humongous sphere machine is a sight to see.

Lapidary Journal had a two part article on building this type
of machine in the September and October 1965 issues. Major
libraries may have copies or reprints can be obtained from:
Lapidary Journal, Reprint Bureau, 60 Chestnut Avenue, Suite
201, Devon, PA 19333-1312. (It was also reprinted in LJ as
"Building a Three-Headed Sphere Machine", August 1979,

The other three-headed machine uses three gear motors mounted
on carriages on slides {usually conventional drawer slides)
so that the motor shafts are spring pressed toward a central
point. Any spring system could be used. I mount the gear
motors on wooden blocks on drawer slides, with a hole in the
back of the block. A spring is placed in the hole and a
threaded rod through a support behind the block presses
against the spring to press the block with the cup on the
motor shaft toward a rock preform. Cranks on the rod outer
end allows spring pressure to be individually adjusted to
give the desired random motion to the preform.


Many types of rock are suitable for spheres. The material
should be essentially fracture free. While the usual lapidary
materials, such as agate and jasper, make excellent spheres,
finding these materials in large fracture free pieces is
difficult. Marble, limestone, granite, rhyolite and similar
materials tends to me more available in large, fracture free
pieces. Many quarries have scrap piles and will let a friendly
rockhound gather a few pieces.

So-called Mexican Onyx (massive calcite/travertine/whatever)
takes an incredible polish. El Marmol in Baja California is
sphere maker's paradise. An enormous abandoned quarry has
millions of tons of banded gold-brown-yellow-tan-red material
free for the taking. Almost any rock with an attractive color
or pattern will make a good sphere, although some will not
polish well.


Many sphere makers believe that a "chop" or "drop" type
diamond saw is ideal for preforming rocks for spheres.
These saws have the blade and motor on an arm pivoting about
a horizontal axis, so that the arm can be lifted, a rock
secured in a vise and the blade allowed to press down against
the rock by gravity. I have a 14" Lortone saw I bought about
25 years ago. I don’t know whether anyone still makes such
saws. They will cut closer to the hub than other type saw.

I know of several different preforming fixtures. Probably
many others have been built. Generally, a cube is cut using
a regular diamond saw, then the preformer is used to cut off
corners from three directions (total of 18 saw cuts) to form
a rough sphere.

I built a preformer for a "chop" saw using a baseplate on
which is fastened an automobile wheel bearing. I turned a
brass index plate to fit in the bearing, with holes every 45
degrees around the plate. The plate has an upstanding central
pin. A Masonite disk having a central hole matching the pin
and a diameter equal to the desired preform diameter is placed
over the plate. A clamp arm clamps a rock on the plate
against the plate. The saw is adjusted to cut near the disk
edge. After a cut is made, the clamp is released and the
plate rotated to the next index hole. Once cuts every 45
degrees are completed, the preform is unclamped and turned
over to another side and the cuts repeated. Difficult to
describe, but it works!

With a conventional saw with a stationary blade and a moving
vise, many people use a wood block with upwardly opening "V".
Once a cube has been cut, a corner is put in the V, which is
parallel to the vise line of motion and clamped with the next
corner carefully aligned with the blade. Repeated cuts result
in the preform.

Most of these preformers produce a preform that is approx-
imately round, but has a number of projecting points that must
be ground at least partially away. A large 60 grit diamond
wheel works best. Carbide wheels get very bumpy very quickly
where the preform is at all large.

Some people grind until the preform is almost a perfect sphere
before putting it in the sphere machine. I am too lazy for
that! I only grind the projection tips away, then start the
rough grind with a slightly oversize cup set and let the rock
bounce and bang. You need to stay nearby, since the very
rough rock may stick in one place. Sometimes you will have to
take it out and grind a little more. I do as little hand work
as possible. I agree with Robert Watson, Jr. who said,
"machines should work, people should think".

An excellent preformer is available from CRS, 6309 St John’s
Rd., Vancouver, WA 98661. I bought one at the Quartzsite
Rockhound PowWow last year (after I had bought a used 20"
conventional saw). That preformer is expensive and a little
slow, but the preformed rock is quite round and needs no
further grinding before being put in the sphere machine,
saving the cost of a large diamond grinding wheel.


Generally, iron cups of some sort are mounted on the motor
shafts and rotate against the preform. With small diameter
motor shafts, a shaft-sized hole can be drilled in the square
end of a conventional iron pipe plug. A setscrew hole is
drilled and tapped in the side of the square end. The plug
is mounted on the motor shaft and a pipe coupling is screwed
onto the plug. Different size couplings can be used for
different sized preforms. The pipe engaging the preform
should be at least 1/3 the diameter of the preform.

Where the preform is very rough, I prefer that the pipe
diameter be about 2/3 the preform diameter, since with the
larger cups preforms are less likely to stick in one position.
After the preform is ground down until the cups almost touch
(and the preform is approximately round with flat spots) I
change to a smaller cup set.

An Aside: Like most sphere makers, I try to grind a number of
similarly-sized preforms before changing cups or grits.
Cleaning the machine (VERY carefully) between grits is a pain!

I use a somewhat different type of cup. I have made a
connector having a motor shaft hole and setscrew at one end
and a 3/4 inch pipe thread at the other. I use standard
plastic sprinkler/irrigation pipe bushings on the connector,
with a 3/4 inch threaded end to thread onto the connector and
a slip fit pipe connector of suitable diameter at the other

For rough grind, I epoxy a piece of pipe on the slip fit end,
since the pipe will resist grinding wear. For finer grinds,
I use a plastic pipe. In order to get greater grinding
surface on the pipe, I generally put a plastic pipe coupling
over the slip fit end and a piece of plastic pipe inside the
coupling. While 220 grit will wear the plastic pipe, it will
last quite a long time. The finer grits wear the pipe very

Many metal suppliers have bins of cut off pipe and will cut
pipe pieces to length for a dollar or two. Plastic fittings
are inexpensive and will last a long time.


A wide variety of polishing pads have been used. I have had
good luck with tight weave commercial carpeting, leather and
rock hard felt fastened over plastic pipes as described above.
These can typically be glued to the pipe with contact cement,
can overlap the end and be secured with hose clamps or strong
rubber bands.

Most conventional lapidary polishes work well. I have tried
several and now use a white powder sold for tumbling; it may
be aluminum oxide but I am not certain. Cerium oxide, zinc
oxide and others work. I have not tried diamond, but it
should be fine with a plastic pad.

Some materials polish best with fairly wet pads, others (such
as jade) seem to be better with almost dry pads that heat up
somewhat. A little oxalic acid seems to help the polish with
"Mexican (calcite) onyx", limestone and marble. Be careful,
oxalic acid is poisonous.


A hospital IV bottle and drip valve assembly makes a fine
water feeder. Or, any tank with a valve, such as a tropical
fish tank needle valve, will work.

I sometimes think that there are as many grit feeder designs
as there are sphere makers. In San Diego County, there are
13 gem and mineral clubs, with over 700 members. I know of
at least about 10 sphere makers, each with an at least
somewhat different grit feeder.

A simple feeder can be made from a shallow plastic tub of the
sort margarine comes in. Connect a tube through the cover
along an edge and lead the tube to the center of the cover.
Mount the tub on a plastic disk (Velcro® works well) with the
disk mounted on a small, slow (about 5-10 rpm) gear motor.
Put grit (not too much) in the tub and mount it to rotate
about a horizontal axis above the preform in the sphere
machine. Each time the tub rotates, when the edge opening is
lowermost, grit will fill the tube to the level of the grit
in the tub. As rotation continues, and the tube passes
horizontal, grit in the tube will slide to the centered open
end and fall onto the preform. A funnel may be necessary to
guide the falling grit to a small preform. While this is
simple and works, the amount of grit per rotation can be
varied only by varying the grit level in the tub, which, of
course, lowers as the grit is used. Also, this (like many
grit feeders) does not work will with grits finer than 220.

Another feeder uses a vertically arranged plastic pipe, 1-2
inches in diameter, having the lower end threaded. A plastic
pipe cap is threaded over the lower end. A small hole is
drilled in the cap center. A metal rod is provided, having
one end ground to a conical point and the other end fastened
to a slow gear motor, abut 10 rpm or so mounted at or near
the uncapped pipe end. A metal washer is placed over the
inside of the cap hole and the rod is mounted along the pipe
axis with the point loosely in the washer. The cap hole is
positioned above the preform. A plastic tube can be connected
to direct grit from the hole to the desired position on the
rock. The pipe is filled with grit and the rod-rotating motor
is started up. The rate of grit feed is varied by screwing
the cap up or down on the pipe. This works best with 220 or
coarser grit. A particularly good, easily adjustable, design.

A more complex, adjustable feeder uses a vertical grit filled
tube with a small lower-end outlet tube. A lever centrally
pivoted with two extending arms has a first arm spring loaded
against the outlet to stop grit flow. A cam (generally two or
more lobes)is mounted on a slow gear motor so that the cam
lobes "bump" the second lever arm to pivot the first arm away
from the outlet tube to release a little grit. Quantity can
be varied by moving the cam toward or away from the lever, or
changing the number of cam lobes. I can’t provide more detail
without sketches and waving my hands!

Finally, a strip of metal twisted about its longitudinal axis
can be inserted through holes in the side walls of a container
(generally a trough) and rotated by a gear motor to provide a
screw action moving grit out of the hole opposite the gear
motor drive end. Tilting the assembly gives limited ability
to control grit flow rate.

A grit feeder is usually not needed for finer grits, e.g. 400
and finer. Very little grit is needed and can be simply
applied with a damp brush dipped in grit. Fine grinding
usually goes rapidly.


I display some of my spheres at some of the half-dozen shows
in San Diego each year. I prefer a simple display, with
nothing to distract from the spheres. Cases used here have a
2x4 foot floor. I cut a piece of plywood to those dimensions
and added one riser at the back. To these I glued a suitable
number of short pieces of plastic pipe. Over this I loosely
spread a sheet of neutral colored cloth. When the spheres
are placed over the pipes, they seem to float on the cloth

Demonstrating sphere making at such shows is fun. People are
amazed how the machine can turn a rough rock into a perfect
sphere. And, another sphere maker is sure to wander by and
engage you in a discussion of how your methods differ!


Sphere making is a fine lapidary specialty. Spheres make
excellent collections, gifts and show displays. Finding
suitable sphere material keeps me out searching the desert
all winter. (Why do the rocks keep getting heavier?) Since,
once set up and running, sphere machines will work away with
little supervision, you can work on other projects while
making spheres.

As I think of other helpful hints and ideas, I will submit
them to the Lapidary Digest. Perhaps if all sphere makers
submit their ideas, we will end up with a true encyclopedia
of sphere making!

John Duncan

Subject: SPHERES: Commercial Sphere Machines

There are two different kinds of machines for making spheres
and beads. In the first machine, individual preforms are held
within two or three cups, which rotate independently, and are
fed a mixture of water and abrasive grit. This type machine
can make either spheres (over 1" in diameter) or beads (1" or
less in diameter), one at a time. The second type only makes
beads, and a number, typically 20, of preforms are put in the
machine with a slurry of water and grit, and the head of the
machine is rotated, grinding all of the preforms into beads.
We will focus on machines which make spheres, not beads.

As of July 1998, I can only find six commercial makers of
sphere machines, and they are: Covington, Diamond Pacific,
Richardson's Ranch, Arrowhead Gemcraft, Adams Lapidary and
the Clasons. If anyone knows of another source, please send
in this information to Lapidary Digest identifying the maker
and describing their machines, with the same types of data as
provided below. The data given below is for illustrative
purposes only; if you are interested in any of these machines,
contact the makers for detailed information.

..Covington makes two models, one for making small spheres
(beads and marbles) and the other for making larger spheres.
Both models have two heads, with the shafts pointing downward.
The spheres are run constantly in a bath of grit, which
obviates the need to constantly brush or otherwise drip grit
onto the sphere; it also keeps the grit slurry out of the
bearings, which obviously is a great idea! They both have
spring loaded cups, making continual adjustments unnecessary.
Finally, in both cases, the angle of the cutting cups can be
increased as the rough sphere becomes rounder and smoother.

The smaller machine is, not surprisingly, called the Little
Sphere Maker; it cuts spheres or beads from 1/4" to 1" in
diameter. It has dual 1/18 hp, 110v motors, is quite small
(16" x 8" x 8"), weighs 25 lbs. and presently costs about

The larger machine, called the Large Sphere Maker (surprise!),
cuts spheres from 1-1/4" to 9", comes with dual 1/3 hp, 110v
motors. This larger version is a floor model, being built into
a metal stand with shelf; its size is (42" x 17" x 42"), and
it weighs 180 lbs. This size and weight is reflected in the
price: ~ $1600.

Further information may be obtained directly from Covington
Engineering Corp. at PO Box 35, Redlands, CA, or by phone at

..Diamond Pacific has recently absorbed Contempo. Just last
year, Contempo came out with a three-head small sphere
machine; the three heads were arranged in a Y-configuration;
the three parts could be taken apart, and only weighed 11
pounds each! However, the machine was not up to neither
Contempo's or DPs standards, and after DP gained control of
Contempo, the engineers at DP began to complete 're-engineer'
machine. From conversations with people at DP, it appears that
the re-engineering will result in completely different sphere
making machines from DP.

Diamond Pacific is located at 2620 W. Main Street, Barstow,
CA 92311; their telephone number is 1-800-253-2954.

..Richardson's Ranch has been producing a three-head machine
for some time now. It sells for $695 and will cut spheres up
to 5". Used copy machine motors drive the cups; they rotate at
85 or 100 rpm.

Richardson's Ranch is located at Gateway Route 440, Madras,
OR 47741; phone 1-800-433-2680

..Arrowhead Gemcraft produces a three head maker which will
produce spheres up to about 6 inches, with an automatic grit
and coolant feed, and with heavy steel grinding cups. Cups for
four sizes of spheres are supplied with the machine. The
machine price is $850 plus freight and sales tax. Made by Dick
Hansen of Arrowhead Gemcraft, PO Box 723, Detroit Lakes, MN
56205-0723. Call them at 218-847-7780.

..Adams Lapidary makes four machines; all are three head
machines. The standard machine will cut up to a 3-1/2 inch
sphere. Rough grinds are done with metal cups and polishing
stage with wooden cups. The machine comes with one set (3) of
hubs, one set (3) of grinding cups and one set (3) of
polishing heads. These machines have automatic grit feed and
water drip feed. Cost is $285 plus freight and handling.
Shipping weight is 55 pounds.

The next larger machine will cut up to 5" sphere ($385.00) and
the Jumbo machine will cut up to a 7" sphere ($485.00) They
also make a three head Marble machine for $225.00.

Contact Joe Adams at 2903 S. Meade Street, Denver CO 80236;

..The Clason brothers (Hank and Cal) produce a machine they
call Excalibur. It has 3 heads, max 5" spheres, 105 rpm geared
motors, 70# shipping wt., breaks into three modules, each of
about 23#. Machines made for each order. Their address is
10100 Lourie Ave, Bakersfield, CA 93312. Hank can be reached
at (805) 393-0280, and Cal at (805) 589-4169.>>



Subject: SPHERES: Clason Brothers and Their Machines


Here in the West, it is generally known that the best sphere
making machines come from Hank and Cal Clason of Bakersfield.
They (brothers) are not on the net, and their production is
usually sold way ahead of production. They participate in
local club shows and demonstrate freely. They currently are
President (Hank) and CFMS Director (Cal) of the Kern County
Mineral Society.

In my personal opinion they both are worthy of wide exposure
as highly ethical, skill sharing humans. Recently there were
a few empty cases at the VGMS Show, no problem, they simply
filled them, looks better for the club. Cal has been Lapidary
Instructor at Zzyzx and lugs his own equipment there as well
as borrowed Genies from the very generous Diamond Pacific.

They both are valued friends.

Hank can be reached at (805) 393-0280, and Cal at
(805) 589-4169.

No, they do not know I am submitting this.


Subject: SPHERES: Where to Buy Used Sphere Machines


A subscriber requested information on a used or cheap sphere
machines. I Believe you also expressed an interest.

I have a good friend, George Jones who is a member of The
Middle Tennessee Gem and Mineral Society and lives at 5025
Franklin Road, Nashville, Tenn. 37220. His phone number is
615-333-3781. Even tho we have the same last name we are not
related. George is a retired Hardware store owner who has a
great machine shop at his home. He deals in new, used and
homemade lapidary equipment. I have made some fantastic
buys from him such as a 20" Contempo Vibrator slab polisher
with two pans that he had reconditioned into a new condition
for a paltry $200.00. I have several other pieces I have
bought from him and the one complaint I ever had was
immediately and cheerfully taken care of. The last time I
went to his home he had 4 or 5 sphere machines. Some he had
made and others were reconditioned and his prices were more
than reasonable.

I recommend Mr. George Jones as not only being an expert
engineer and repair man of lapidary equipment, but of great
personal integrity whose retired mission in life is making
his customers happy with the lapidary equipment he supplies
them with.

Bill Jones

Subject: SPHERES: About Sphere Making

I own a homemade sphere machine and would advise you to buy a
used commercial unit if you cannot afford a new one.If you are
1/2 electrician and 1/2 handy man you could make a machine. I
know an older gentleman in waning health that makes a lot of
spheres that is selling some of his equipment. I could call
him if you wish. I have bought equipment and rough rock from
him and have always been treated fairly.

Do be advised that sphere making involves a lot of sawing and
grinding before the rock will fit into the machine. There is
also a problem with grit traveling into the electric motors,
and they have to be replaced (best to find surplus company
for such things). It is time consuming, and in many cases you
can buy spheres wholesale cheaper than you can make them, but
that is not near as much fun!


Subject: SPHERES: Some Comments

Hi Hale,

I think it's a great idea to do a whole issue on Sphere
Machines, however I have no experience with the commercial
machines you mention. I basically copied the Richardson's
model which I took many photos of at Quartzite, where they
demo it, and gave me lots of info. about it.

I got a lot of help making mine, one friend welded up the
angle iron for the base, another guy who works in a machine
shop made me the aluminum motor uprights, and I custom
designed a grit dispenser with a small clock motor and plastic
pipe fittings. So no, I don't make or sell them, although it
was fun.

I find the hardest part of sphere making is cutting the rough
down to the "tri-octahedron-shape" (??) before it goes in the
machine, which typically takes 26 cuts in the slab saw. Then
I usually have to baby sit the machine for 20-40 hours
(depending on hardness) to get the stone round, so it won't
be spit out of the rotating cups. Needless to say, I don't
make many spheres while working full time.

It would be nice to hear other people's experiences, and
advice to automate the major processes of this hobby. For
example, I know there is a slab saw "rotating cutter thing"
that is supposed to speed up the slab saw cutting. If anyone
used this device (sold by a fellow at the Quartzite Pow-Wow
each year) I'd be interested in how it does.

Look forward to the article.

Wayne Moorhead
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