Bob Johnson on sun 4 mar 07
Thanks for the advice, everyone! Building a ball mill looks doable.
Hank has a photo of his home-made one
at http://www.murrow.biz/hank/kiln-and-tools.htm. I also found
detailed instructions at
http://www.digitalfire.com/gerstleyborate/ballmill/. I'm not a
welder, so I plan to build the frame out of plywood. Not sure where
to find the other parts, but I imagine I'll get an education on
pillow block bearings, pulley ratios, cold roll steel rods, and hydraulic hose.
Georgies, my nearest supplier, sells the jars separately---as I
imagine other ceramics suppliers do. Incidentally, can anyone give me
a reason to prefer the $92 porcelain one over the $34 vitreous china one?
Because of other pending projects, this one will take a while, but
I'll let you know how it comes out...
Bob
At 3/4/2007 03:38 PM, you wrote:
>You can build one easily with a 1/4 hp motor, some bearing, two 1
>inch steel rods
>with rubber hose squeezed onto them, two sizes of
>a v-groove wheel and a v-grooved , and a frame.
>For the pebbbles you can make porcelain ones and hi-fir them. For the
>jar, search ebay, labx.com.
>Marcia
>
>Marcia Selsor
>http://marciaselsor.com
Bob Johnson on sun 4 mar 07
There has been some recent discussion on ball milling (not to be
confused with the huevos vs cojones thread), so I'm hoping that some
of you have the experience and expertise can help me with the
following questions:
1. Does one need to spend big bucks ($800+) to buy a ball mill from a
pottery-equipment supplier, or would one of the much-cheaper United
Nuclear models work for
ceramaic materials? Those were referenced on the
CeramicMaterials.Info site
, but I'm
leery of a neoprene container. I note that some of you are apparently
using rock polishers, so the plastic containers may be OK---but I'm
concerned that highly abrasive materials might just eat through the
container or that the grinding speed may be wrong.
2. Are there materials that are too hard or too coarse to be ground
by a mill with ceramic balls? I'm thinking here of volcanic ash. What
are the limits?
3. Is ball milling always done with wet mixture, or do potters
sometimes mill dry materials?
Thanks,
Bob
Dave Finkelnburg on sun 4 mar 07
Bob,
You can build a ball mill, if you are willing to
spend the time and determine the sheave size for your
motor RPM and mill diameter. See below for how to
figure that.
The lining of a ball mill wears (so does the
grinding media), but not so rapidly. You can use a
sturdy plastic container for quite a few batches
before you would have a problem.
Yes, some things are too coarse, but that's
subjective. The bigger the grinding media, the
coarser the feed a mill will grind. Since you seem to
be talking about a very small mill, like a quart
capacity, you probably want 1/4 to 3/8-inch media and
feed no larger than coarse sand. If you sieve out the
stones and trash from volcanic ash with window screen
it should ball mill fine.
A ceramic jar will grind the charge much faster
than a plastic jar. That's because there is less give
and the grinding is more thorough. Steel ball mills,
like the United Nuclear, are typically lined with a
flexible material so they will last longer, at the
expense of grinding speed.
You can mill either wet or dry, your choice. Wet
eliminates dust problems so most studio ball milling
is wet.
Good glazing,
Dave Finkelnburg
Per Joseph Newton, in his, "Introduction to
Metallurgy," the minimum
speed at which a mill charge will "centrifuge" can be
calculated by the
formula, N = 54.19/square root of R, where N is the
critical speed in
revolutions per minute, and R is the internal radius
of the mill in feet. Newton
adds most commercial mills, "are operated at speeds
ranging from 50 to 80
per cent of the theoretical critical speed."
From: Bob Johnson
1. Does one need to spend big bucks ($800+) to buy a
ball mill from a
pottery-equipment supplier, or would one of the
much-cheaper United
Nuclear
models work for
ceramaic materials? Those were referenced on the
CeramicMaterials.Info site
,
but I'm
leery of a neoprene container. I note that some of you
are apparently
using rock polishers, so the plastic containers may be
OK---but I'm
concerned that highly abrasive materials might just
eat through the
container or that the grinding speed may be wrong.
2. Are there materials that are too hard or too coarse
to be ground
by a mill with ceramic balls? I'm thinking here of
volcanic ash. What
are the limits?
3. Is ball milling always done with wet mixture, or do
potters
sometimes mill dry materials?
____________________________________________________________________________________
Need Mail bonding?
Go to the Yahoo! Mail Q&A for great tips from Yahoo! Answers users.
http://answers.yahoo.com/dir/?link=list&sid=396546091
Maurice Weitman on sun 4 mar 07
Bob Johnson a =E9cri:
>[...] 1. Does one need to spend big bucks ($800+) to buy a ball mill from a
>pottery-equipment supplier, or would one of the much-cheaper United
>Nuclear models work for
>ceramaic materials?
Hola, molineros de los cojones,
Depending on which United Nuclear (heh!) ball=20
mill you're eyeing, you may wish to consider=20
another PIECE OF CRAP from Harbor Freight's=20
beloved, revered, and reviled Chicago Electric
=
=20
which looks inzactly like the United Nucular=20
jobbie, but for less than half the price.
They have hard rubber containers, so they run=20
very quietly, which is a good thing, because=20
they'll take a bit longer to achieve the same=20
result as a metal or porcelain jar.
I actually like 'em for small quantities for which I'm in no rush.
Regards,
Maurice, in sunny Fairfax, California, enjoying=20
the buds on our Asian Pear, Nectarine, and Fig=20
trees, not to mention all the pollen from the Bay=20
and Acacia trees (also saw our first shooting=20
stars of the season on a hike yesterday), as I=20
recover nicely from my last, with any luck, hand=20
surgery, and look forward to seeing my claybuds=20
in Lewaville!
Hank Murrow on sun 4 mar 07
On Mar 4, 2007, at 10:58 AM, Bob Johnson wrote:
> There has been some recent discussion on ball milling (not to be
> confused with the huevos vs cojones thread), so I'm hoping that some
> of you have the experience and expertise can help me with the
> following questions:
>
> 1. Does one need to spend big bucks ($800+) to buy a ball mill from a
> pottery-equipment supplier, or would one of the much-cheaper United
> Nuclear models work for
> ceramaic materials? Those were referenced on the
> CeramicMaterials.Info site
> , but I'm
> leery of a neoprene container. I note that some of you are apparently
> using rock polishers, so the plastic containers may be OK---but I'm
> concerned that highly abrasive materials might just eat through the
> container or that the grinding speed may be wrong.
I have not experienced rapid wear on the plastic olive containers that
I use. However, the three gallon porcelain jar ($92 three years ago)
that runs on my homemade mill grinds stuff much faster than the same
media in the plastic jars. It seems to be the action of the media
falling and grinding the load against the porcelain walls of the jar.
Go here for a look at my $120 homemade mill.
http://www.murrow.biz/hank/kiln-and-tools.htm
>
> 2. Are there materials that are too hard or too coarse to be ground
> by a mill with ceramic balls? I'm thinking here of volcanic ash. What
> are the limits?
Yes, if the materials are bigger than about 8 mesh..... it can take a
long time to get them ground fine enough for glaze use. I use a jaw
crusher to take 1.5" rocks down to 8_10 mesh. Then they go into the jar
mill. Sometimes for 24 hours, other times just for two. Paradoxically,
the softer materials tend to clog up the crusher, while the hard stuff
goes right on through. It is opposite with the Ball mill........
>
> 3. Is ball milling always done with wet mixture, or do potters
> sometimes mill dry materials?
I have never ground dry, as my stuff would clump up. The water/slurry
tends to 'carry' the material in suspension.
If you look around old mining districts, often you can still find
'assay' type jaw crushers. They can run off a Briggs & Stratton 5 hp
engine, or a good 3 hp electric. I got mine, along with a plate mill
that runs on the same shafts for $200 four years ago.
Now, I am trying to come up with a 'cheap to build' 15_20 gallon ball
mill for preparing the wild porcelains I am digging. I dry the slip out
to plastic consistency in Dacron 'sacks' hung from the rafters in my
studio. lovely thing having these 40# 'socks' hanging around......
great potential there!
Cheers, Hank
www.murrow.biz/hank
Marcia Selsor on sun 4 mar 07
You can build one easily with a 1/4 hp motor, some bearing, two 1
inch steel rods
with rubber hose squeezed onto them, two sizes of
a v-groove wheel and a v-grooved , and a frame.
For the pebbbles you can make porcelain ones and hi-fir them. For the
jar, search ebay, labx.com.
Marcia
Marcia Selsor
http://marciaselsor.com
Patrick Cross on sun 4 mar 07
Another possible source for the rollers might be from a couple of old
typewriters or printers.
Patrick Cross (cone10soda)
On 3/4/07, Marcia Selsor wrote:
>
> You can build one easily with a 1/4 hp motor, some bearing, two 1
> inch steel rods
> with rubber hose squeezed onto them, two sizes of
> a v-groove wheel and a v-grooved , and a frame.
> For the pebbbles you can make porcelain ones and hi-fir them. For the
> jar, search ebay, labx.com.
> Marcia
>
> Marcia Selsor
> http://marciaselsor.com
>
>
> ______________________________________________________________________________
> Send postings to clayart@lsv.ceramics.org
>
> You may look at the archives for the list or change your subscription
> settings from http://www.ceramics.org/clayart/
>
> Moderator of the list is Mel Jacobson who may be reached at
> melpots@pclink.com.
>
Paul Herman on mon 5 mar 07
Hello All,
Vince is right, a ceramic jar is the way to go. It grinds between the
pebbles and the jar.
As potters, you should be able to make your own jars, don't you
think? Just make it nice and thick, and cylindrical and vitreous. You
can do it. You can make your own pebbles too.
Best,
Paul Herman
Great Basin Pottery
Doyle, California US
http://greatbasinpottery.com
On Mar 5, 2007, at 6:24 PM, Vince Pitelka wrote:
>
> Steve -
> But it is important to point out, as others have done, that a ceramic
> milling jar will mill much faster than a rubber or plastic jar,
> because
> there is greater impact as milling media tumbles against the walls.
> - Vince
>
claystevslat on mon 5 mar 07
Bob -- That United Nuclear ball 3 pound ball mill is
suspiciously similar in appearance to the Harbor Freight
3 pound ball mill. The H.F. item is quite reasonable
in price. OTOH, it lacks the elegant "United Nuclear"
nameplate.
My observation is that any ball mill, including a homemade
item, will do the work -- only if it turns too quickly
will the milling not take place. The rubber cannisters
may break down over time, but any similarly sized container
will work the same.
Milling wet avoids a nasty dust cloud when opening the
cannister.
- Steve Slatin
--- In clayart@yahoogroups.com, Bob Johnson wrote:
>
> There has been some recent discussion on ball milling (not to be
> confused with the huevos vs cojones thread), so I'm hoping that
some
> of you have the experience and expertise can help me with the
> following questions:
Hank Murrow on mon 5 mar 07
On Mar 4, 2007, at 9:41 PM, Bob Johnson wrote:
> Thanks for the advice, everyone! Building a ball mill looks doable.
> Hank has a photo of his home-made one
> at http://www.murrow.biz/hank/kiln-and-tools.htm. I also found
> detailed instructions at
> http://www.digitalfire.com/gerstleyborate/ballmill/. I'm not a
> welder, so I plan to build the frame out of plywood. Not sure where
> to find the other parts, but I imagine I'll get an education on
> pillow block bearings, pulley ratios, cold roll steel rods, and
> hydraulic hose.
You can find the critical speed for the jar you pick by consulting
Cardews, "Pioneer Pottery". It is in the appendix.
Cheers, Hank
www.murrow.biz/hank
Vince Pitelka on mon 5 mar 07
Steve Slatin wrote -
"My observation is that any ball mill, including a homemade
item, will do the work -- only if it turns too quickly
will the milling not take place. The rubber cannisters
may break down over time, but any similarly sized container
will work the same."
Steve -
But it is important to point out, as others have done, that a ceramic
milling jar will mill much faster than a rubber or plastic jar, because
there is greater impact as milling media tumbles against the walls.
- Vince
Vince Pitelka
Appalachian Center for Craft, Tennessee Technological University
Smithville TN 37166, 615/597-6801 x111
vpitelka@dtccom.net, wpitelka@tntech.edu
http://iweb.tntech.edu/wpitelka/
http://www.tntech.edu/craftcenter/
WJ Seidl on tue 6 mar 07
TO Paul's post, might I add...
If you are going to make your own jar, be sure to include some internal ribs
running vertically from cap to bottom. They don't have to be large, just
about 1/2 inch high or so. Three should do. This will aid in the tumbling,
much like a clothes dryer drum.
Best,
Wayne
-----Original Message-----
From: Clayart [mailto:CLAYART@LSV.CERAMICS.ORG] On Behalf Of Paul Herman
Sent: Monday, March 05, 2007 11:41 PM
To: CLAYART@LSV.CERAMICS.ORG
Subject: Re: more ball mill questions...
Hello All,
Vince is right, a ceramic jar is the way to go. It grinds between the
pebbles and the jar.
As potters, you should be able to make your own jars, don't you
think? Just make it nice and thick, and cylindrical and vitreous. You
can do it. You can make your own pebbles too.
Best,
Paul Herman
Great Basin Pottery
Doyle, California US
http://greatbasinpottery.com
On Mar 5, 2007, at 6:24 PM, Vince Pitelka wrote:
>
> Steve -
> But it is important to point out, as others have done, that a ceramic
> milling jar will mill much faster than a rubber or plastic jar,
> because
> there is greater impact as milling media tumbles against the walls.
> - Vince
>
____________________________________________________________________________
__
Send postings to clayart@lsv.ceramics.org
You may look at the archives for the list or change your subscription
settings from http://www.ceramics.org/clayart/
Moderator of the list is Mel Jacobson who may be reached at
melpots@pclink.com.
Michael Wendt on tue 6 mar 07
David Waln near here is a great porcelain
potter who makes almost all his own
equipment. He said he goes down by
the river and finds nice round quartz
pebbles and stones. By choosing
really white ones, he gets no color
even though they do wear and unlike
porcelain balls, they contain no flux
and no clay, just silica.
Incidentally, he made his own filter
press setup for clay, too. wow!
Regards,
Michael Wendt
Wendt Pottery
2729 Clearwater Ave
Lewiston, ID 83501
USA
208-746-3724
http://www.wendtpottery.com
wendtpot@lewiston.com
Hank Murrow on tue 6 mar 07
On Mar 6, 2007, at 7:05 AM, Michael Wendt wrote:
> David Waln near here is a great porcelain
> potter who makes almost all his own
> equipment. He said he goes down by
> the river and finds nice round quartz
> pebbles and stones. By choosing
> really white ones, he gets no color
> even though they do wear and unlike
> porcelain balls, they contain no flux
> and no clay, just silica.
> Incidentally, he made his own filter
> press setup for clay, too. wow!
Dear Michael;
In Southern oregon near Ashland, there is Emigrant Lake. All around the
edge of the lake, there are quartzite rocks(very round and hard) that
you can 'size' by walking around the lake edge until you see the size
rock you want. I collected two five gallon pails the last time I was
down there with Jim Robinson. They will be the grinding media for a
15_20 gallon ball mill I want to build.
Cheers, Hank
www.murrow.biz/hank
Ron Roy on wed 7 mar 07
Hi Paul,
Yes - I was not clear about that - some grinding - but my understanding is
the real work is done by crushing.
I don't think it works the same in rubber or plastic because there is some
give - but the balls - hitting each other with material between them would
do some crushing - if the speed is right.
RR
>Hi Ron,
>
>If no grinding happens between the pebbles, then a plastic or rubbed
>lined mill jar would not grind at all.
>
>I would say that a hard jar works a lot better, but some grinding
>does take place between the pebbles.
>
>Pioneer Pottery by Cardew has a section on ball mills that gives a
>formula for determining the best speed (rpm) for any given jar diameter.
>
>best,
>
>Paul Herman
Ron Roy
RR#4
15084 Little Lake Road
Brighton, Ontario
Canada
K0K 1H0
Dave Finkelnburg on wed 7 mar 07
Paul,
You have it right. The charge should roll far
enough up the side of the mill that it "cascades" down
over other balls in the mill and smashes particles in
between the balls as they make contact. Of course,
only a tiny area on any two balls actually touches, so
it takes a lot of impacts to crush much.
A hard jar works better because it doesn't absorb
the shock of impacts from above it, but rather,
permits that energy to go into crushing particles.
In a ball mill running at the right speed, the
balls impact upon each other most often, and almost
never smash into the wall or lining. Thus the balls
wear out but the liner doesn't...at least not very
fast.
The amount of "charge," the water and material to
be ground, is also critical to ball mill grinding. If
there is too much charge in the mill the impacts
between balls are cushioned and no grinding occurs.
Good potting!
Dave Finkelnburg
From: Paul Herman
If no grinding happens between the pebbles, then a
plastic or rubber
lined mill jar would not grind at all.
I would say that a hard jar works a lot better, but
some grinding
does take place between the pebbles.
____________________________________________________________________________________
Don't pick lemons.
See all the new 2007 cars at Yahoo! Autos.
http://autos.yahoo.com/new_cars.html
Ron Roy on wed 7 mar 07
Seems to me many of us have a false conception of how ball mills work.
The speed of turning is crucial - the balls should get all the way to the
top of the jar and fall down - crushing particles between the balls and the
jar.
In other words it's a crushing action that gets the job done rather than a
grinding action.
Otherwise why the careful instructions in the books about the speed in
relation to the balls and the size of the jar?
The illustrations also bear this out - the balls falling down if the speed
is right.
RR
>Hello All,
>
>Vince is right, a ceramic jar is the way to go. It grinds between the
>pebbles and the jar.
>
>As potters, you should be able to make your own jars, don't you
>think? Just make it nice and thick, and cylindrical and vitreous. You
>can do it. You can make your own pebbles too.
>
>Best,
>
>Paul Herman
>
>Great Basin Pottery
>Doyle, California US
>http://greatbasinpottery.com
>
>
>On Mar 5, 2007, at 6:24 PM, Vince Pitelka wrote:
>
>>
>> Steve -
>> But it is important to point out, as others have done, that a ceramic
>> milling jar will mill much faster than a rubber or plastic jar,
>> because
>> there is greater impact as milling media tumbles against the walls.
>> - Vince
>>
>
>____________________________________________________________________________
>__
>Send postings to clayart@lsv.ceramics.org
>
>You may look at the archives for the list or change your subscription
>settings from http://www.ceramics.org/clayart/
>
>Moderator of the list is Mel Jacobson who may be reached at
>melpots@pclink.com.
>
>______________________________________________________________________________
>Send postings to clayart@lsv.ceramics.org
>
>You may look at the archives for the list or change your subscription
>settings from http://www.ceramics.org/clayart/
>
>Moderator of the list is Mel Jacobson who may be reached at melpots@pclink.com.
Ron Roy
RR#4
15084 Little Lake Road
Brighton, Ontario
Canada
K0K 1H0
Paul Herman on wed 7 mar 07
Hi Ron,
If no grinding happens between the pebbles, then a plastic or rubbed
lined mill jar would not grind at all.
I would say that a hard jar works a lot better, but some grinding
does take place between the pebbles.
Pioneer Pottery by Cardew has a section on ball mills that gives a
formula for determining the best speed (rpm) for any given jar diameter.
best,
Paul Herman
Great Basin Pottery
Doyle, California US
http://greatbasinpottery.com
On Mar 7, 2007, at 8:33 AM, Ron Roy wrote:
> Seems to me many of us have a false conception of how ball mills work.
>
> The speed of turning is crucial - the balls should get all the way
> to the
> top of the jar and fall down - crushing particles between the balls
> and the
> jar.
>
> In other words it's a crushing action that gets the job done rather
> than a
> grinding action.
>
> Otherwise why the careful instructions in the books about the speed in
> relation to the balls and the size of the jar?
>
> The illustrations also bear this out - the balls falling down if
> the speed
> is right.
>
> RR
pdp1@EARTHLINK.NET on thu 8 mar 07
Hi Ron,
In my mental model of it...
Crushing and skidding ( or that skidding is still crushing if more or less
at an acute angle)...
...the surface tension of the liquid likely plays some
roll...
Phil
el v
----- Original Message -----
From: "Ron Roy"
> Hi Paul,
>
> Yes - I was not clear about that - some grinding - but my understanding
> is
> the real work is done by crushing.
>
> I don't think it works the same in rubber or plastic because there is some
> give - but the balls - hitting each other with material between them would
> do some crushing - if the speed is right.
> Ron Roy
> RR#4
> 15084 Little Lake Road
> Brighton, Ontario
> Canada
> K0K 1H0
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