Old Lapidary equipment

Suddenly, I received an older Star Cabbing machine in used but
running condition. I am, and will remain primarily a jeweler, but I
loved making my own high dome cabochons when I had access to a
lapidary workshop years ago.

I’d like to befriend and use this Beast, which is the largest tool I
have ever acquired, so I am looking to the members of good ol’
Orchid for some advice and direction. The Beast has six 8 inch
wheels and a flat lap, and is currently hiding under filthy layers
of stone mud and rust, and will need cleaning and replacing of some
parts. I have no instruction manual with it, and a quick online
search has informed me that Star was bought by Barranca. I literally
haven’t even unearthed a model number yet. I’ve found numerous
lapidary forums online, which are actually helping me generate more

What’s the best way to clean this machine?

Does anyone have experience with, or know anyone I could contact
about, reconditioning and using old lapidary equipment?

Is this brand worth the time, and money to recondition? I have only
used Lortone and Diamond Pacific equipment before.

Are there any great lapidary books that are recommended? Reputable
experts, or forums I should be contacting?

Any help is much appreciated, since the Beast and I would like to
stop eyeing each other dubiously.


try going to AFMS Home Page then go to regional
federations, then choose the area that you live in, then find your
state that should give you a list of gem and mineral clubs/societies
in your state/area

most of these groups have people well experienced in cabochon
cutting and various machines. my local society has four cabbing
machines in our workshop, and we do all our own repairs, etc.

if you are not in the usa, then i don’t have any reference group for
you to go to.

there are several schools, such as william holland school of
lapidary arts, that might also be able to assist you.


Does anyone have experience with, or know anyone I could contact
about, reconditioning and using old lapidary equipment? 

Hi, Michelle - where are you located?

Best regards,

Hi Michelle,

It is hard to know exactly what you have without a picture or better
description, but all of the Star equipment I see pictured on line
looks very sturdy. These things usually run forever, but can use some
repair if they were run a lot or misused. A few things to start you
off. Take a look at some images of lapidary machines on line (google
"cabbing machine images") and you will see that many of the machines
are similar and that they usually use a drip feed of water to the
wheels. Therefore the wheels and the hood over them and the pan
beneath are all designed to run with water all over them, so don’t
hesitate to wash it down. You can use shop towels and whatever
detergent cleaner you like to break up any dirt, grease and rust. You
can also use a hose to help clean it. The only areas you need to try
to keep somewhat dry are the motor and cord. the hoods should protect
the motor somewhat. You may have to clean out plastic water lines or
needle valves or provide a bucket of water if the water system is

Some have pumps that pump water from below and work off little
aquarium bubblers or pumps attached to the motor shaft. The latter
may need cleaning out.

Turn the shaft by hand and see if it turns smoothly or is locked up.

Examine the wheels to see if there are any cracks or broken pieces.
If not and if it turns smoothly or even just a little roughly, you
can plug it in and start it up. Stay to the side when you first start
any grinding equipment in case there is a broken wheel that flies
apart. If the machine looks really poor, you might want to start it
up the first time outdoors with the wheels pointed in a direction
where flying debris will not hit anything. Just being careful, not
likely that anything is broken.

Some of these motors run very hot, so do not worry about that. Do
smell for burning wires and after it has run a little, turn it off
and listen to it spin. When the motor is not making any noise, it
should be pretty quiet. If it rumbles a lot, it may need new
bearings. You may be able to run a machine with worn bearings a while
and just tolerate the noise, if the bearings don’t heat up too much.
Look for a couple of oil holes and oil with something like SAE 30
non-detergent oil or whatever the machine label says. You likely will
not find anyplace for oil, as most of these motors have sealed

You can look at lapidary catalogs to see what wheels they have that
look like yours. If you have diamond wheels that still have some life
left in them, you are in luck and have hit the jackpot. But the
machine may have expanding drums that take silicon carbide paper or
diamond belts or it may have a couple of grinding wheels that are
silicon carbide. Not as good as diamond, but perfectly adequate for
anything but corundum and will even work that but will wear down
doing it.

I could guide you through the whole process of figuring out what you
have, but it would get to be a long message. A better bet would be to
make contact with your local Gem and Mineral Club. There will
definitely be some old codgers there who know all about these
machines and can help you figure out what grits you have on your
wheels if it is not completely apparent on looking. You probably have
two hard grinding wheels of about 80 and 200 grit and then possibly
four resin bonded diamond wheels of 280, 400, 600 and 1500 grit
diamond, but that’s a guess. Im thinking that the “flat lap”: you’re
referring to is a polishing pad on the end of the thing and that
takes a felt or leather or pellon polishing disk that you use with
cerium or alumina oxide or very fine diamond polish. If you can’t
find help you’re welcome to email me at rkersey@tds. net and I can
probably help you figure it out.

Any decent sized public library should have a book or two with
chapters on cutting cabs. If you check, you’ll see that the new
cabbing machines with fresh new wheels are about $1000 and up, so
what you have is probably well worth saving and fixing up. If the
bearings are really bad, they can be replaced by a machine shop and
it probably wouldn’t cost that much and you’d have a virtually new
machine. I don’t think you will find any used equipment like this
that works for less than $400 or so…

Good luck, cabbing is fun.

Therefore the wheels and the hood over them and the pan beneath
are all designed to run with water all over them, so don't
hesitate to wash it down. 

We’ve been out of the loop since Xmas, pretty much. Missed out on
something about burning diamonds so amateurs can see the light,

Roy’s is good advise, but I’ll take it down tothe bottom line, if
you haven’t already fixed up your machine. You say you have eight
wheels and a polishing pad on the end, as I recall - or was it 6 -
eight in wheels… No matter, what you have is called a
combination unit no matter who made it.Combination units are
intended to be disassembled and it’s your job as a lapidary to know
how to do that, even ifit might take you a while to figure it out.
It is probably made to be taken apart easily - I know I had a Beacon
Star that had wing nuts on the top so you could just pull it off.
The shaft should have split bushings ofsome sort that un-bolt and
you can lift the whole shaft out. There being two reasons - one is
for cleaning, which is a constant process, and the other is that
that’s how you change the wheels. You take out the shaft, there will
be some sort of shaft collars to hold the wheels on, and then there
are shaft spacers to hold them a distance apart. This is made
intentionally so that you, the user, can take it apart to change
wheels if nothing else. It should be easy and obvious even without a
manual, not counting frozen bolts from sitting in a garage. When you
put it back together make sure the bushings and bearing surfaces are
squeaky clean and maybe just wipe the bushings with the tiniest bit
of lithium grease. If it’s really dirty I’d recommend starting with
a putty knife to scrape up the dust instead of making mud with
water. Then clean it - even take it outside and hose it down…
Put it backtogether, check your water and drain and crank that
sucker up…

John D.

Hi John D,

Thanks for adding to what I posted. Can’t believe I wrote something
that long and missed the part about taking off the wheels. I agree
with you, it would be a good idea to remove the wheels and clean the
shafts. The wheels may very well have labels on the sides that tell
what kind of wheel and what size grit, which would be helpful in
deciding on a sequence from coarse to fine when using the machine.
Keep all the spacers in order and remember that one side (I believe
it is the left side) will have a left handed thread and will tighten
the “wrong” way. This is to keep the wheels tightening rather than
loosening from the twisting brought on by rotation.

I also agree that you might want to shovel out the dry rock dust if
possible, before turning everything into mud again. Sometimes it
comes out better wet, Just have to try dry first and see. Also might
be a good idea to disassemble the hoods, if they are made to come

As I think I said, sometimes something comes up we didn’t
anticipate, and some of the best resources are the old codgers in the
local Gem and Mineral Society. There may even be someone who had one
of these when it was new, who can tell you every quirk.

Let us know if you have other questions…

The wheels may very well have labels on the sides that tell what
kind of wheel and what size grit... 
I also agree that you might want to shovel out the dry rock dust
if possible, before turning everything into mud again. 

And if you put it all back together and one of your wheels seems
like it doesn’t have any oomph – usually the 80 grit goes first –
dismount that one and remount it backward, because sometimes the
grit will wear off in a directional pattern. (Unless the prior owner
has already exercised that economy.) Re getting rid of old swarf:
from the standpoint of respiratory health, you’re much better off
handling it wet.

Let me brag a bit and say that if you’re near Maryland, you won’t go
wrong contacting the Gem Cutter’s Guild in Baltimore.


some of the best resources are the old codgers in the local Gem
and Mineral Society. 

You’re welcome Roy, first off. And for a newbie at lapidary work I’d
also second the advice of getting into a lapidarysociety or club.
Cutting rocks and stones is more complicated than it might seem at
first. I started in a summer class as a teenager and then got
nominated the lapidary department at a job as a result of that
little bit of experience, but just acquiring an old machine and
expecting to take off with it without some guidance is probably not
very realistic. Describing the rock crowd as “old codgers” is often
not too far off the mark, but you’ll find those folks to be friendly
and enthusiastic, by and large. Usually those societies and clubs
are cheap or even free, too. I prefer tobe called a slab licker,
myself… John D.

Hi Michelle, I have been out of commission for a couple three weeks
or so, so just going through, the over 300 posts and trying to catch
up. I read the responses to your initial post, and it seems as if
everyone has given good to better advice. I wouldn’t throw my two
cents in, except that the Star Diamond is one of my favorite older
machines. I rebuilt one that I call my “dream machine”. If we are
talking about the same machine, they have a 1" stainless steel shaft
riding on two bearings, wrapped in rubber. The hood is held down by 4
acorn nuts, and there will be a series of needle valves to bring
water to the wheels. If you haven’t already started the process of
reconditioning, and are happy with the progress, or would just like
some more input, e-mail me @Thomas_H_Louthen_III. I would be happy to talk
you through the whole process, resulting in one of the best machines
for cabochon production ever. I don’t mean to speak blasphemy, but
this is better than Diamond Pacific’s Titan, a 3,000.00 dollar
machine. Thomas III

think I have a star diamond cab machine in storage along with a 10 ’
star diamond saw… & a Beaver polishing machine. have any pics of


How can I share files and pictures with the list?

Or… send the files to the attention of service@ganoksin.com and
we will upload them for you…


will take some pic’s this weekend…