Janet H Walker on thu 5 mar 98
When I've looked at ball mills in a catalog, they always seem to me
to be an extraordinary price for something that looks like a motor
that turns a canister 'round and 'round. No electronics, no precision
controls, no user interface, no ... So, can someone tell me why they
are such expensive things to acquire?
On the topic of ball mills, I've heard some competing thoughts on
whether a studio potter needs one.
School A. "All the materials you buy these days are extremely finely
ground already and there just isn't anything really left to do. So you
don't need one."
School B. "Maybe those funny bubbles are a result of favorite suspect ingredient here> not being finely enough ground. Try
ball milling it."
Anyone with a broader or deeper perspective want to weigh in on this
one? Jonathan Kaplan?
Thanks,
Jan Walker
Cambridge MA USA
BobWicks on fri 6 mar 98
Jan:
You are right, ball mills just tumble around and around..nothing fancy. As a
matter of fact I made one with some roller bearings and I used an old rubber
tire for the tumble chamber. The only reason you might need one is if you are
making your own glazes. The more the mill works the finer the ingredients are
ground and the finer the ingredients you will find that the fire temperature
is lowered somewhat.
Bobwicks@aol.com
Vince Pitelka on fri 6 mar 98
>When I've looked at ball mills in a catalog, they always seem to me
>to be an extraordinary price for something that looks like a motor
>that turns a canister 'round and 'round. No electronics, no precision
>controls, no user interface, no ... So, can someone tell me why they
>are such expensive things to acquire?
Jan -
I have wondered the same thing. The few companies that make ball mills seem
to have a corner on the market, and can charge what the market will bear. I
wonder why some of the newer ceramic equipment manufacturers don't make less
expensive ball mills? They are very simple machines, and all the parts can
be purchased off the shelf. For anyone with a little mechanical ingenuity
it is a simple matter to build one, and you can make your own ball mill jars
and porcelain pebbles.
At U-Mass we had an AMACO ball mill, and the rubber on the friction rollers
died. Those are the rollers which support and rotate the jars. I contacted
AMACO for replacement prices and was completely appalled at what they were
asking. So I purchased some heavy-duty reinforced rubber hose with a 3/4"
inside diameter, and cemented it to the 3/4" shafts with a good contact
adhesive. Worked great. The whole machine was just a very simple
angle-iron frame, with the two rubber-covered 3/4" shafts supported by
pillow-block ball bearings. One shaft extended beyond the bearing, and had
a large single-belt pulley on it - perhaps 12" diameter. On the lower level
of the frame was a 1/4 HP 1750 RPM motor, mounted on a vertical bracket with
slotted holes so that it could be moved up and down to adjust belt tension.
On the motor shaft was a very small pulley, driving the large pulley on the
roller shaft. Only one roller is powered. The other one rolls from the
friction of the rotating jar, which lays sideways on the two roller shafts.
Two small horizontal wheels at either end prevented the jar from migrating
along the shafts.
I once saw a very clever design for a homemade ball-mill. It incorporates
four high-quality ball-bearing fixed-mount (non swiveling) caster wheels to
support the ball jar, with smaller casters mounted at either end to keep the
jar from migrating endwise as it rotates. Below this setup the motor is
mounted on a hinged platform, with a belt long enough to reach up and
encircle the ball-mill jar. When the hinged motor mount is lowered, the
weight of the motor it pulls the belt tight around the jar, and when
running, it rotates the jar without any other driving mechanism. This
requires the use of a jar at least ten or twelve inches in diameter, with
the smallest possible pulley on the motor. Otherwise the jar will turn too
fast to do any good. In use the ball jar is filled about one third with
flint pebbles or porcelain balls, and one third with a thin slurry of the
material to be ball-milled. The jar should not be filled more than about
two thirds of the way, or it will not work properly.
- Vince
Vince Pitelka - vpitelka@DeKalb.net
Home 615/597-5376, work 615/597-6801, fax 615/597-6803
Appalachian Center for Crafts
Tennessee Technological University
1560 Craft Center Drive, Smithville TN 37166
DONPREY on fri 6 mar 98
Jan,
A few years ago I made my own ball mill......not to mill commercially
available materials, but to mill local materials (rocks) for glazes. It is
true that the whole device is relatively low tech and the parts not that
expensive. My guess is that a large part of the price has to do with the
small demand for this item. It is expensive to maintain production of a low
volume product. I'm a bit amazed that anybody is still producing a ball mill
of the size and life expectancy appropriate for studio pottery use. It
doesn't seem like there would be much demand.
Also, I can't imagine myself having a ball mill taking up valuable studio
space just to mill commercial material occasionally.
Don Prey in Oregon
Marco Milazzo on fri 6 mar 98
Janet:
Shimpo used to manufacture a ball-mill contraption that you attached to a Shimpo
head. I've never seen one "in the flesh," just pictures in old ceramics magazin
wonder if anyone knows if they still exist, if they work and how much they cost?
Marco Milazzo in Houston, Texas
flannery@phoenix.net
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Janet H. Walker wrote:
When I've looked at ball mills in a catalog, they always seem to me
to be an extraordinary price for something that looks like a motor
that turns a canister 'round and 'round. No electronics, no precision
controls, no user interface, no ... So, can someone tell me why they
are such expensive things to acquire?
Marcia Selsor on sat 7 mar 98
I use a homemade ballmill I inherited in the shop 23 years ago. I rebuilt the
rollers a few years ago when I became interested in making terra sig. The
rollers are about 2' long. and hold two quart jars.
We've also used it for special glazes.
Marcia in Montana
Barbara Lewis on sat 7 mar 98
Janet and Marco:
I used to have a shimpo with one of those ball mill attachments that I used
for making terra sig. It worked great and was easy to attach to the wheel.
I don't know if they still make it though. Good luck, Barbara
At 08:54 AM 3/6/98 EST, you wrote:
>----------------------------Original message----------------------------
>Janet:
>
>Shimpo used to manufacture a ball-mill contraption that you attached to a
Shimpo
>head. I've never seen one "in the flesh," just pictures in old ceramics
magazin
>wonder if anyone knows if they still exist, if they work and how much they
cost?
>
>Marco Milazzo in Houston, Texas
>flannery@phoenix.net
>
>
>
>-----------------------------------------------------------------------------
>Janet H. Walker wrote:
>
>When I've looked at ball mills in a catalog, they always seem to me
>to be an extraordinary price for something that looks like a motor
>that turns a canister 'round and 'round. No electronics, no precision
>controls, no user interface, no ... So, can someone tell me why they
>are such expensive things to acquire?
>
WellSpring ClayWorks
5412 Well Spring Road
La Plata, MD 20646
(301) 932-3915
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