[docweathers]

Commercially made ball milling jar seem ridiculously expensive, so I am thinking about making my own.

I understand that there are several potential problems with doing this.

1) Throwing an absolutely round jar... I have figured out how to solve this.
2) I understand that porcelain tends to warp drying and firing-- is this true and what can be done about it? (I have no experience with porcelain.)
3) I understand that the porcelain commonly available to Potters is softer than what is used in ball milling jars. Is this true? Where is harder porcelain available?

[Ben]

docweathers, on 18 March 2013 - 12:10 PM, said:

Commercially made ball milling jar seem ridiculously expensive, so I am thinking about making my own.

I understand that there are several potential problems with doing this.

1) Throwing an absolutely round jar... I have figured out how to solve this.
2) I understand that porcelain tends to warp drying and firing-- is this true and what can be done about it? (I have no experience with porcelain.)
3) I understand that the porcelain commonly available to Potters is softer than what is used in ball milling jars. Is this true? Where is harder porcelain available?

1. You don't need a round jar. Make a jar and mount it in a round metal sleeve that has been turned true and cylindrical or make your ball mill so that it has a cradle to hold the jar.
2. see #1. It makes #2 a non issue. Usually you want to make ball mill jars thicker than normal wares to make up for the wear of the grinding media inside. This thickness will counter warpage that can be seen in very thin porcelain wares.
3. Try it and see. How soft could it be? (caveat: this depends on how the stuff is fired and the clay body. If it is meant to mature at cone 10~11 and you only get it up to ^9 it won't be as hard as it could be. )
So, do you have a ball mill already and are you looking to replace your current jars or are you making a mill?
How big a charge do you want to mill in 1 cycle? ( charge will be about 1/3 the capacity of the jar + 1/3 grinding media with 1/3 airspace room for the stuff to move around and tumble)
Have you got a copy of "A Potters Alternative" by Harry Davis?

Best,
Ben

[docweathers]

I'm thinking about making a ball mill. I have figured out how to build a gizmo that will quickly interchange between a ball mill and a power slab roller. I would like to be able to mill 2 or 3 quarts at a time.

You have offered some good suggestions. I'm trying to narrow down to the most likely successful alternatives because as a beginner ,I am trying out all too many new things, literally dozens of glazes on hundreds of test tiles etc.

[bciskepottery]

I recall a video of a potter who made a ball mill . . . he made a wood disc that sat on top of his wheel splash plan. He had cut out a rectangle so his jar, with wide rubber bands or bicycle inner tubes, could sit in the rectangle on the wheel head. He would turn on the wheel and the jar would turn. Can't find the video, though.

[Pompots]

2.- The best way to avoid warping of porcelain is to dry it very slow, very little handling, and to fire it slow. That will keep the shape of your cylinder intact.

[Ben]

docweathers, on 18 March 2013 - 09:24 PM, said:

I'm thinking about making a ball mill. I have figured out how to build a gizmo that will quickly interchange between a ball mill and a power slab roller. I would like to be able to mill 2 or 3 quarts at a time.

You have offered some good suggestions. I'm trying to narrow down to the most likely successful alternatives because as a beginner ,I am trying out all too many new things, literally dozens of glazes on hundreds of test tiles etc.

You really should find a second hand copy of the Harry Davis book. Might try getting a copy through inter library loan first to check it out. Also "Pioneer pottery" by Cardew may have some info for you. I can't recall off the top of my head. I haven't been in that book in a couple of years.

If you want to mill a 3 quart charge you'll need an 8 to 9 quart jar. 2 gallons. at that size you might want to use the pipe method for housing your jar. You may also consider using a pipe type vessel lined with porcelain "bricks" as outlined in the Harry Davis book. This setup is going to be HEAVY. I'd guess 20 to 30 lbs for the jar/media/charge of glaze to be ground. Something to consider.

Are you planning on variable speed for your rollers? That would allow you to use many different size jars. Neat idea getting 2 uses out a capital investment like a slab roller. Good thinking.


Ben

[docweathers]

bciskepottery, on 18 March 2013 - 07:49 PM, said:

I recall a video of a potter who made a ball mill . . . he made a wood disc that sat on top of his wheel splash plan. He had cut out a rectangle so his jar, with wide rubber bands or bicycle inner tubes, could sit in the rectangle on the wheel head. He would turn on the wheel and the jar would turn. Can't find the video, though.

What was he using for a jar?

[docweathers]

Ben, on 19 March 2013 - 04:48 AM, said:

docweathers, on 18 March 2013 - 09:24 PM, said:

I'm thinking about making a ball mill. I have figured out how to build a gizmo that will quickly interchange between a ball mill and a power slab roller. I would like to be able to mill 2 or 3 quarts at a time.

You have offered some good suggestions. I'm trying to narrow down to the most likely successful alternatives because as a beginner ,I am trying out all too many new things, literally dozens of glazes on hundreds of test tiles etc.

You really should find a second hand copy of the Harry Davis book. Might try getting a copy through inter library loan first to check it out. Also "Pioneer pottery" by Cardew may have some info for you. I can't recall off the top of my head. I haven't been in that book in a couple of years.

If you want to mill a 3 quart charge you'll need an 8 to 9 quart jar. 2 gallons. at that size you might want to use the pipe method for housing your jar. You may also consider using a pipe type vessel lined with porcelain "bricks" as outlined in the Harry Davis book. This setup is going to be HEAVY. I'd guess 20 to 30 lbs for the jar/media/charge of glaze to be ground. Something to consider.

Are you planning on variable speed for your rollers? That would allow you to use many different size jars. Neat idea getting 2 uses out a capital investment like a slab roller. Good thinking.


Ben

At your suggestion, I have requested Davis's book from interlibrary loan. I have seen excerpts from it. It looks like the guy would rather build some gizmo rather than have a brand-new shiny one given to him.

The first version will be a single speed. If that works, I will add more sprockets to the motor so that I can have several discrete speeds. I will be using bicycle chain drive because you can drive a sprocket from either side of the chain. This will allow me to change the direction of one of the rollers by rerouting the chain. In the scrap pile where I get steel for my welded art, I found a bunch of really nice rollers from a scrapped post office package conveyor. These things will take anything I can dish out.

my biggest obstacle this point is figuring out the good jar. A friend of mine uses large glass jars but they do deposit a slight amount of glass. the my art welding scrap piles I do have some large diameter tubing that Davis' brick idea might work. To determine that, I will have to wait until I get his book to see how he is doing that.

Thanks for your helpful suggestions

Larry

[perkolator]

docweathers, on 19 March 2013 - 09:37 AM, said:

bciskepottery, on 18 March 2013 - 07:49 PM, said:

I recall a video of a potter who made a ball mill . . . he made a wood disc that sat on top of his wheel splash plan. He had cut out a rectangle so his jar, with wide rubber bands or bicycle inner tubes, could sit in the rectangle on the wheel head. He would turn on the wheel and the jar would turn. Can't find the video, though.

What was he using for a jar?

I've also seen this video, but can't find it either. He used a square of 3/4" plywood that was slightly larger than his splash pan. He put 4 pegs/screws on the bottom edge so it would locate/stay put on the splash pan. He cut out two rectangles (I think) that were the size of his jar. To use it, lay jar in the hole and turn the wheel on = very clever ball mill for like $5. The jars he was using looked like the pint size jars commercial glazes come in, but IIRC they looked much thicker (more like a Nalgene). I think he was in Europe, so his jars may be much different. You could probably use a plastic chemical jar from a labware supplier.

Another option is something like what Shimpo offers as a ball mill adapter for their electric wheels. Seems like a fairly simple design that can be easily replicated for a different brand of wheel.

[AtomicAxe]

Most porcelain ball mills have some form of grog in them (like molochite I believe) .... it helps resists the warping in firing and the issues with repeated abuse. Also, they are about 3/4" thick, so plan on that fun. throwing it seems to be a little futile as no one is that perfect. If I were you, I would still use a wheel to make it, but instead make a solid form first that is carved perfectly round, make a mold of it then cast like 4 or 5 of them. Chances are, one will be what you need. Also, remember you are going for something that can stand abuse ... not be light and pretty ... so thick, really thick. And don't glaze the inside.

[OffCenter]

AtomicAxe, on 20 March 2013 - 10:16 AM, said:

Most porcelain ball mills have some form of grog in them (like molochite I believe) .... it helps resists the warping in firing and the issues with repeated abuse. Also, they are about 3/4" thick, so plan on that fun. throwing it seems to be a little futile as no one is that perfect. If I were you, I would still use a wheel to make it, but instead make a solid form first that is carved perfectly round, make a mold of it then cast like 4 or 5 of them. Chances are, one will be what you need. Also, remember you are going for something that can stand abuse ... not be light and pretty ... so thick, really thick. And don't glaze the inside.

It would be a little bit stronger if you leave the grog out. The advantage it gives in resisting warping, etc. may outweigh the slightly less strong clay but it is a factor to consider. If using grog, use very little. The more you use the weaker the fired clay.

Jim

[R Fraser]

I bought a ball mill from an EBay vendor that is very servicable for about 150.00. I have milled several rounds of glaze for Raku and cone 10 reduction using the "jars" made from schedule 40 PVC plumbing fixtures (6" pipe, closed end cap, reducer and rubber cap secured with a SS band clamp. I bought ceramic ball media from a ceramic supply vendor in 1 inch, .75 inch and 0.5 inch sizes. It seems to work great, and I have made my own jars since for far less than the EBay vendor was charging. I imagine over time some of the PVC winds up abrading off the inner walls, but I have assumed any present in the glaze slurry burns out early in the firing and have not seen any ill effects in fired ware.
Richard

[docweathers]

It sounds like I have some really good options for making cheap ball milling jars. With the PVC ones I would wonder if you would lose milling efficiency by having the smooth plastic walls versus the unglazed ceramic roughness. With the PVC, do you feel like it takes longer to ball mall your glaze than it ought to? I do have some 6 inch schedule 40 in my scrap pile

I have an idea how how to make your own ball milling jar. My understanding is that the reason you cannot just throw one is that it's impossible to get things absolutely round and square by just throwing. My experience says this is true.

Get a piece of plastic tubing that has an inside diameter about the size you want the outside diameter of your jar, maybe 8 inches in diameter. Cut it off very square at the height you want the jars roller surface to stop.

Take the blue feet off of my Giffen grip and throw a cylinder a little taller than the plastic cylinder and just slightly smaller, so that you can still slip the plastic cylinder over the clay cylinder. Put the blue feet back on the Giffen grip. Put the plastic cylinder over the clay cylinder and tighten the Giffen until it grasps the plastic cylinder.

Reach inside the clay cylinder and press it out until it is all the way up in contact with the plastic cylinder that it is inside of. Collar in the clay sticking out the top of the plastic tube to form a neck for a lid. Let dry in the plastic cylinder until it shrinks away and plastic cylinder can be removed.

Do you think this would work? Any suggestions on how to make it work better?

[Ben]

docweathers, on 21 March 2013 - 05:14 PM, said:

Do you think this would work? Any suggestions on how to make it work better?

I think this is a great idea. In fact, this is probably the best idea I have seen proposed for homemade ball mill jars and I'm probably gonna try it myself. Last time a just threw the jar and this sounds quicker and more true/square.
You might try some sort of release agent between the pipe form and the clay. Maybe use oil or grease or paper, or wax paper or oiled paper... Anything that would keep the clay from sticking.
Otherwise you could make a plaster mold for the same function as the pipe form but that's a whole lot more work for something you might use 3 or 4 times every 5 to 10 years.

Ben

[AtomicAxe]

All my ball mills are pvc ... the cost of replacement is incredibly cheap and instead of the contents milling themselves against the side of the jar, its all about the medium you use to mill your contents. I normally use stainless steel balls in 3 different sizes, it does the same job and any scraping on the side of the jar will generally be minimal. I think the ball mill and the 5 jars I made in college are still being used today by students. It DOES take a little longer, but I normally just ball mill overnight anyways.

[docweathers]

This sounds like the cheap, easy approach... Which is my style

What diameter PVC and what number of which size of stainless steel balls do you use?

How fast do you turn your PVC jar?

[AtomicAxe]

I make long boys, a 1'-1.5' long 4" pipe, 4" cap on one end, 4"-2" reducer on the other, 3" section of 2" and a rubber end cap that tightens with a screw driver. At one point and time, i had a 6" tube that was about a foot long, reduced down to 4" and held a ton of slip/glaze .... I don't ball mill that much glaze anymore, so a 4" is fine and holds about a gallon of liquid with the medium.

stainless medium depends on how long your ball mill is. as for milling medium sizes, I go with a ratio one quarter 3/4" SS, half 1/2" SS, and one quarter 1/4". it needs to be enough to go from end to end of the tube on it's side, be able to have medium at the bottom, but still have medium able to travel up the curve to fall back down on itself. you can actually use more on a smaller diameter but longer jar, than a shorter but fatter jar that holds the same volume.

And how fast, depends on the jar and the medium, not so fast as to let the ball medium slam into itself from the top (knocking it off the ball mill) or rotate around, and not too slow as to not let it go up the side, and fall back down onto other medium. Basically what you are looking for is around a 120-140 degree rotation from absolute bottom of the curve in the jar to the shoulder before it starts to drop back down again. Also, I should note, viscosity of your substance inside the jar also changes how fast you rotate the jar. slower moving ... slower speed.

Sorry, not an exact science really.

[Marcia Selsor]

Doc,
If you are milling smaller quantities you could use a rock tumbler. You can find them on ebay.

Marcia

[docweathers]

Rock tumblers usually are hexagon steel chambers. Is there any problem with metal wearing off the chamber and getting into the glaze?

[docweathers]

docweathers, on 21 March 2013 - 03:14 PM, said:

It sounds like I have some really good options for making cheap ball milling jars. With the PVC ones I would wonder if you would lose milling efficiency by having the smooth plastic walls versus the unglazed ceramic roughness. With the PVC, do you feel like it takes longer to ball mall your glaze than it ought to? I do have some 6 inch schedule 40 in my scrap pile

I have an idea how how to make your own ball milling jar. My understanding is that the reason you cannot just throw one is that it's impossible to get things absolutely round and square by just throwing. My experience says this is true.

Get a piece of plastic tubing that has an inside diameter about the size you want the outside diameter of your jar, maybe 8 inches in diameter. Cut it off very square at the height you want the jars roller surface to stop.

Take the blue feet off of my Giffen grip and throw a cylinder a little taller than the plastic cylinder and just slightly smaller, so that you can still slip the plastic cylinder over the clay cylinder. Put the blue feet back on the Giffen grip. Put the plastic cylinder over the clay cylinder and tighten the Giffen until it grasps the plastic cylinder.

Reach inside the clay cylinder and press it out until it is all the way up in contact with the plastic cylinder that it is inside of. Collar in the clay sticking out the top of the plastic tube to form a neck for a lid. Let dry in the plastic cylinder until it shrinks away and plastic cylinder can be removed.

Do you think this would work? Any suggestions on how to make it work better?

I have finally tested this idea and it works great. There are only two caveats:

1) it takes several days of drying before the milling jar shrinks enough to break free from the PVC tube around it. It's best to absolutely leave it alone until it pops free on its own.
2) it takes some careful calculation to figure the shrinkage of the neck of the jar so that the 4 inch plastic pipe cap fits over the collar when the bottle is dry. Luckily, I got it right the first time.