I am trying to figure out a way to clamp a piece of ring wax
from the inside so that it would spin evenly and not throw a
home-made wax lathe out of kilter. I am using a small motor to
turn the wax and would like to use hardwood to clamp the wax
because it is light. The clamping system has to be symmetrical
so that the weight is balanced. Put your thinking caps on!!
I am trying to figure out a way to clamp a piece of ring
wax...
You didn’t mention if you have attached a chuck of some sort to
your motor shaft. Could you give a few more details of your
set-up to help us help you.
Hello Marshall, Melt the wax on to something you can clamp in
your machine. I use a locking nut that has a star washer
permanently attatched to it. Something from a car,I think. If my
car door falls of, I’ll know. I threaded the shaft of a small
motor and the whole thing works great. Tom Arnold P. S. And it
makes a mess too neat to believe
I am trying to figure out a way to clamp a piece of ring
wax from the inside so that it would spin evenly and not throw
a home-made wax lathe out of kilter. I am using a small motor
to turn the wax and would like to use hardwood to clamp the wax
because it is light. The clamping system has to be
symmetrical so that the weight is balanced.
I use the wax cylinder holders from the Matt Wax lathe for most
of the turnung that I do on either a flex shaft or on my Unimat
lathe. I will sometimes use a rod with a flattened end and melt
the flattened end into the center of the wax for smaller items.
Carving wax is difficult to grip with the jaws of a lathe chuck.
Rick Hamilton
Richard D. Hamilton
A goldsmith on Martha’s Vineyard
USA
Fabricated 14k, 18k, 22k, and platinum Jewelry
wax carving, modelmaking, jewelry photography,
and sailing whenever I can… http://www.rick-hamilton.com
You didn’t say how you wanted the ring to rotate. I’ll assume
you ant the axis of rotation to be essentially the centerline of
the finger.
One way I’ve held tubular/hollow items is with a rubber tube
slipped over a bolt & then squeezed between the head of the bolt
& a nut tightened down on the rubber tube. This scheme works
because rubber is ‘plastic’ & moves instead of compressing. I’ve
never used it on wax though. Hopefully the wax will have
sufficient tensile strength not to pull apart. Here’s the
directions.
Select a piece of rubber tubing with about the same outside
diameter as the finger hole of the ring blank. The length should
be about 1/4 in (6 mm) longer than the width of the ring blank.
The extra length is determined by the space between the outside
of the tube & the inside of the ring blank. The rubber in the
extra length will be compressed to fill the open space. A little
experimentation may be necessary to determine the correct length
of tube. There should be enough to provide a minimum of 1/8" (3
mm) clearance between the ring blank & washers on each side.
Select a bolt that will just go through the center of the
rubber tubing. The bolt should be long enough to allow for a flat
washer on both sides of the rubber tube, a nut on one side &
sufficient extra length to be held by the chuck of a lathe, flex
shaft hand piece etc. Depending on the size of the hole in the
blank, an 8-32, 10-32, or 1/4" machine screw of the correct
length will probably work. These sizes are available with
slotted, phillips or hex heads. A hex headed bolt (when it’s got
a hex head its called a bolt) would provide better control in
this instance.
Place a flat washer on the bolt.
Slide the rubber tube on the bolt. Slide it on so the tube
pushes the washer against the head of the bolt.
Slide the ring blank over the rubber tube.
Place a flat washer and nut on the bolt. Tighten the nut
until the the rubber tube just contacts both washers.
Locate the the ring blank approximately midway between the
washers.
Tighten the nut until the rubber tube expands & holds the
ring blank securely. Over tightening the nut will cause the ring
blank to break.
Place the end of the bolt in the chuck & turn the ring
blank.
Since the ring rotates essentially on its axis, any unbalanced
condition is minimized.
Most hardware stores in the US stock several sizes & wall
thickness of rubber tubing as well as the nuts, bolts, & washers.
To clamp the ring from the inside ( I.D.) one needs an
expandable arbor, this can be fabricated from aluminum or
hardwood or plastic… drill and tap a NPT (national pipe thread
in the end of the piece to be used for the arbor… then turn
the (O.D.) outside diameter to match the inside diameter of the
ring… then slot the arbor with a hacksaw or jewler’s saw
longitudinally symetrically about the axis of rotation… then
slide on the ring (wax) and insert a pipe plug into the end of
the arbor… tightening carefully as it will expand the arbor,
via the taper of the pipe thread… taper national pipe thread…
should hold wax but be carefull not to over tighten it will
expand a considerable amount…
Best of Luck!
Bob Parsons
Master machinist
Experimental Fabrication Dept.
Ford Scientific Research Lab
Dearborn Mi
i’m not sure about the hardwood being a very workable idea. i
would suggest getting a solid round bar of wax and a ‘t’ nut from
the hardware store ( if the jaws on your lathe go big enough, get
a bigger t nut that will fit approximately into the hole of your
wax tube). put a small bit of wax on the nut, when it melts apply
the hot nut onto your tube/bar. the tube/ bar is on end on a
level surface. before the wax cools completely, true up the t
nut with a metal probe or whatever by eye. a 3 inch length of
tube/ bar works great. there will be ‘run out’ but this can be
eliminated by just turning at a medium speed and taking a course
with the cuttter.
I have used a wooden mandrel covered in masking tape, set in the
lathe. I cut the wax to approximate width and size it with my wax
reamer and slip it on the mandrel. The masking tape surface (the
sticky side is not out), holds the wax in place for turning. I
don’t like doing it out of a solid tube of wax because its so
hard to get the finger size exact while turning on the lathe.
Hello Marshall. GRS makes a benchmate that has different
holders the one that I thinking of is, inside ring holder. Can
you hold a nut in your motor that is a left hand thread,and bolt
too. Just slip your wax on and tighten up and away you go.
I am trying to figure out a way to clamp a piece of ring wax
from the inside so that it would spin evenly and not throw a
home-made wax lathe out of kilter. I am using a small motor
to turn the wax and would like to use hardwood to clamp the
wax because it is light. The clamping system has to be
symmetrical so that the weight is balanced.
Not a problem. If you have access to a lathe, make 2 pieces that
will clamp together. The pieces would be shaped in such a way,
they when they are clamped together they form so mething similar
to a pulley. The pieces would have to be tapered enough to hold
all inside ring sizes, but not too tapered so that small sizes
wouldn’t touch the sides when it screwed together. ring width
can be as variable as you want with the length of the screw you
use to anchor the 2 pieces.
On the shaft, there is a back plate that will keep the right
side from slipping down towards the motor.
I was thinking on making one of these from an old screw shaft
and aluminum. so it would fit in my flex shaft.
I tried that, but it failed. the ring is flat on the inside, and
the mandrel is tapered. if you put too much pressure on the far
outside edge while ‘lathing’, the ring sort of tilts on the
mandrel. not good.
I have a friend in a machine shop working on a ‘step’ mandrel
with all 1/2 sizes in the steps. 5 through 12. (15 steps)
I bought a tool from GRS a while ago. It is an attachment for
the benchmate and allows you to hold a ring from the inside and
work on it. It consists of a set of plastic collets, split down
the length with a tapered opening on one end. A bolt with a
metal cone shape fits into the collet. When you screw the bolt
into the handpiece the collet expands and holds the ring in
place. I took a piece of Delrin and turned it true on my lathe,
then drilled a hole and tapped it to accomodate the screw. By
using the different size collets, I can take a piece of wax, make
sure the ring hole is the correct size then put it on my lathe
and turn or mill the outside. It is a little difficult to tighten
the collet enough to hold the wax in place, and not crack it. If
you don’t tighten it enough the wax has a tendency to turn
slightly on the collet, or move up and down the length of the
collet. One thing I did to help a bit was to take a graver and
raise little stitches on the collets. They dig slightly into the
wax and hold it better. Don’t know if this might help you with
your problem but from the message below it sounds as though it
might. – Steven Brixner - Jewelry Designer - San Diego CA USA
mailto:@Steven_Brixner3http://home.att.net/~brixner
I am asuming that your lathe has a chuck on the shaft. I use a
“MATT MINI LATHE” wax lathe, it comes with reusable metal
arbors(6 prong collets) that are melted into the wax(solid wax
rod) so that it can be turned by a flex shaft. It is possible to
purchase these arbors seperately for about 8 dollars american.
I turn the I.D.,O.D.,and the Width of the ring on this lathe,
then I cut it off and continue carving. If it becomes necessary
for me to turn more on the Outer Diameter or even up the “comfort
fit” bevels on the Inner Diameter after I have cut the piece from
the arbor I cut a shoulder the same measurement as the I.D. on
the arbored wax rod still in the lathe. I slip the wax onto the
shoulder. It must fit snugly. It takes some getting used to but
if you use the hard GREEN wax rod then it works well. Since you
can turn the wax down to any size you need never have a sloppy
fit. If you want more on this let me know and I
will go into more detail.