Little conundrums in building a 100 lb capacity (including media) ball mill

[oldguy]

Little conundrums in building a 100 lb capacity (including media) ball mill

 

You modify a stand to suit.

 

You bolt shafts on pillow block bearings in place.

 

You bolt motor in place.

 

 

 

Because everything is bolted in place solid.

 

You are then faced with the question of how to get a drive belt on/off & have a way to adjust belt tension.

 

The answer is a swing arm idler.

 

That way you can use a slightly oversized belt.

 

Slide the belt on & take up any slack with the swing arm idler.

 

Then you can also adjust belt tension or replace the belt with ease.

 

Took me 15 minutes wandering around a (you pull it) auto wrecking yard to find a swing arm idler that would work.

 

Cost $5.

 

 

　I bought 2 differing types, just in case the the one above could not be modified to suit.

 

Edited April 28, 2011 by oldguy

[NightHawkInLight]

I like it. I would like it even more if it was sitting in my workshop. What is the diameter of those drums?

[oldguy]

Drums are 12 inch PVC sewer pipe (½ inch wall).

 

I cut several in 12X12 & a couple 8X12.

 

So, I can mix & match running 2 jars of either size at a time.

 

I also plan to cut some 6 inch PVC pipe, for 6 inch jars.

 

Design is such I can move the free wheeling roller over tighter to accommodate 6 inch jars.

 

 

 

This big boys end weight loaded running two 12X12 jars will be about 200 lbs.

 

So, I guess I will bolt on some big swivel castor wheels on the legs .

 

Otherwise this thing would be a real PITA to move around.

 

LOL, I would feel safe running this in my shop with single benign chemicals.

 

For BP & other chems not so benign, it will go in a blast bunker.

 

Plan there is concrete floor, sand filled rebar reinforced cinder block walls lightly mortared together.

 

With a plywood roof covered with a pond liner membrane to make the roof waterproof with several layers of sand bags on top of that.

Edited April 28, 2011 by oldguy

[marks265]

Old Guy,

 

If you should have problems with your belt tensioner you could use something like this as this is a usual industrial configuration:

 

http://www.overlyhautz.com/motorbases1.html

 

The tensioner you have is simple and cheap and should work but options are nice.

 

Mark

[Arthur]

Swede had a plan for a mill that had the motor on a hinged plank of wood, below the rollers and used the weight of the motor to tension the belt and the movement of the pulley to release the belt if needed. Very simple and very effective.

 

http://www.thegreenman.me.uk/tool/bm.html I've seen this mill and it runs well. I like the fact that the motor is NOT underneath the rollers in the spill zone. You will get a spill of powder sometime. I also like the use of conveyor rollers - I've seen rollers rated at 250Kilos each so a pair should be adequate for any mill needs. For use in a bunker I also like the mill being very low! The bunker does not have to be too big. Also be careful that the drums are within easy lifting weight and place range, a 100Lb drum is not a trifle and as you get older you realise that back damage is long term. A mate made a mill to take 35kilos of powder at a time BUT he shrank the design because the drum needed power handling to lift it when full of even ceramic media (plus who needs 35kilos every few hours!).

[oldguy]

There are a lot of ways to do this.

I built mine with things I had on hand, or could get cheap, quick & easy.

 

The larger 12X12 inch drums I am building will be about 50 or 55 lbs each (loaded).

That I can handle.

 

Mine is taller than most, but I prefer that, so no or very little bending over is involved.

[oldguy]

Idler arm to adjust belt tension in place

[MadMax]

Nice job dude.

 

If you're gonna make it that big maybe you could also make a special purpose insert for it for planetary ball milling. Sort of like a smaller diameter free rotating mill container within balanced balanced out by a weight or something. Then maybe a couple different size pulley wheels to go into high speed planetary mode. That way you could run it in that mode if you needed a little bit of stuff in a very short time no problem.

[oldguy]

Nice job dude.

 

If you're gonna make it that big maybe you could also make a special purpose insert for it for planetary ball milling. Sort of like a smaller diameter free rotating mill container within balanced balanced out by a weight or something. Then maybe a couple different size pulley wheels to go into high speed planetary mode. That way you could run it in that mode if you needed a little bit of stuff in a very short time no problem.

 

Thanks,.............

 

But, I prefer designs that are as simple as a plow horse. They have passed the test of time like old soldiers. My mill is simple to use, hardly anything to go wrong and if anything does, it's simple to diagnosis & fix. Planetary mills are high energy. There is no need for a high energy mill with pyro comps. High energy mills mixed with high energy compositions is a recipe for disaster.

Edited April 30, 2011 by oldguy

[Bonny]

That's a great looking mill oldguy. Looking at the table, the height is probably close to an ideal standing height when you add the lawn tractor tire(s) to use it as a star roller too!

[oldguy]

Belt on, I guess I should wire in the motor & see how big momma spins.

[pyrokid]

What a beauty, nice job oldguy!

[oldguy]

What a beauty, nice job oldguy!

 

Thanks for the kind words.

The reality is, what I am hoping for is simple, functional & efficient.

 

 

[killforfood]

Old Guy,

Very nice design, simple yet strong. Mikhail Kalashnikov would be proud.

I'm anxious to see how you finish the sewer pipe ends.

[oldguy]

Old Guy,

Very nice design, simple yet strong. Mikhail Kalashnikov would be proud.

I'm anxious to see how you finish the sewer pipe ends.

 

For jar ends, plan was to use plywood.

 

 

That plan changed. Passing a place going out of business & selling everything that wasn't bolted down. I noticed a big acrylic case with thick walls for sale cheap ($10). I offered $5 & he sold it to me for that.

 

 

Plan now for a couple jars is to cut & use doubled up acrylic instead of plywood. Simply because I got the acrylic material so cheap. That & you can bond (5000 psi) acrylic to pvc with a product called WELD-ON #40.

 

http://www.eplastics...HESIVE-IPS40-PT

Edited May 1, 2011 by oldguy

[FrankRizzo]

Old guy,

 

Another thing that you can do is make PVC sheets from pipe. You simply cut a length of pipe slightly longer that the outside diameter of your jar, then us a saw to make a slice up the length, place in the oven @ 250F to soften, then open-up the pipe into a sheet. You'll need to soften and open it up a few times to get the curve out, then soften really good one last time and sandwich it between two pieces of plywood with a few disc weights or car batteries keeping everything flat until it cools. Cheap PVC sheet.

 

I then use a Jasper jig to cut a circle out of the sheet with a router. A flush trim bit can be used to make it perfect once attached to the jar.

[oldguy]

Intersting Frank,

 

The cheap easy way would be plywood with a formica skin.

Still pondering it all.

 

Edited May 3, 2011 by oldguy

[killforfood]

OldGuy,

 

The jar has always been the conundrum for me. Once you exceed 4", commercial end caps become very expensive. I've never been able to think up a good cheap solution but your plywood and formica (currently acrylic) end caps are a solution that anyone can do cheap and easy. Thanks for the idea.

 

1. trace the OD of the pipe ends on a sheet of acrylic, HDPE or plywood.

 

2. Trace the ID of the pipe ends on another sheet of acrylic, HDPE or plywood faced with formica.

 

3. Use jigsaw to cut out end pieces and sand to fit if needed.

 

4. Concentrically join the two pieces with appropriate glue.

 

5. Use a 4" hole saw on one end and attach 4" access pipe.

 

6. Bond ends to jar with appropriate glue and screws.

 

I think this winter when I am not so busy I will rebuild my old ball mill and make some 8" or 10" jars using your method.

 

Currently my one and only jar is a 6' or 8" piece of steel pipe and it worries me that a steel jar could cause sparks. When I first used it my only media was a bunch of used solid carbide machining inserts. They worked great except by chance I emptied the jar after dark one night. when I poured the meal and inserts into a sieve I was horrified to see a shower of tiny sparks! Why it didn't ignite, I'll never know. To this day I thank the almighty creator for sparing another fool. I still have the inserts but only use them for ball milling Ti turnings.

 

[Mumbles]

The one thing I don't care for with that design is the flat end from which you would pour from. It will be difficult to get all the media and composition/chemical out. As well, cleaning could be a challenge. Most similar designs utilize ends that are removable, typically by screws sunk into the jar walls, and held on with wing nuts or something similar.

[oldguy]

The one thing I don't care for with that design is the flat end from which you would pour from. It will be difficult to get all the media and composition/chemical out. As well, cleaning could be a challenge. Most similar designs utilize ends that are removable, typically by screws sunk into the jar walls, and held on with wing nuts or something similar.

 

Because of the inherent difficulties you point out. I am still pondering how best to construct the access end of the jars. It seems to me if one drilled holes in the drum end rim, then inserted threaded rod, using epoxy to hold the threaded rod securely in place. Then drilled a series of holes through the end cap matching the protruding threaded rods. Then used nuts on the threaded rod to hold the end cap cover in place. That would allow the complete end cap of the jar to be removed from the drum with relative ease. I may go that route, still pondering & not sure yet.

 

 

[oldguy]

After a lot of pondering. I think I will spend the money and buy some flat sheet PVC to use as ends on the jars. In part because the application of PVC to PVC is inexpensive, strong & simple to apply. With a good bond, its both waterproof & air tight. I want both, because I envision a time where some wet milling will be done, as well as charging the jar with a gas or in a vacuum.

 

On the 12X12 jars I will install a short length of 6 inch PVC pipe as access, with a 6 inch rubber pressure test cap as a closure. On the 6 inch jars I will do the same, except use 4 inch PVC as access.

 

6 inch access on a 12 inch diameter jar allows plenty of easy access, as does 4 inch access on a 6 inch jar.

 

The reason for my decision is that these are large heavy jars. I don’t want to have to remove the jar, set it upright & unscrew 6 or 8 wing type nuts to remove the whole end every time to inspect the milling progress of the content.

 

It is far simpler & quicker to unscrew a single radiator hose type clamp, remove the rubber cap to look inside the jar while it is still setting on the rollers. I don’t know about others, but during milling, I like to inspect the content several times during the process. So, I can make a judgment call on when milling is completed.

 

As far as emptying or cleaning the jars. With wide access ports, I don’t believe there will be any difficulty. If need be, other than ordinary soap & water, I can use my little high pressure spray washer to insure they are thoroughly clean.

 

I have invested this much attempting to build a durable reliable efficient mill. I might as well invest a little more to build top notch jars to go with it.

 

 

[killforfood]

http://img.photobucket.com/albums/v236/killforfood/Pyro/ThumblersTumbler-1.jpg

 

http://img.photobucket.com/albums/v236/killforfood/Pyro/ThumblersTumbler.jpg

 

 

 

OldGuy,

 

 

I don't believe I'll ever build jars as large as your 12" so my preference would be a smaller jar like the Thumbler's Tumbler with one end completely open for loading, emptying and cleanout. This would eliminate the constriction of the 4" pipe but would also require that larger O.D. rolling surfaces be added to the jar so that the ends would have an adequate surface to seal and attach to. The added rolling surface would have to be tough enough to bear the entire weight of the jar, and its contents, provide a smooth rolling surface and one end would have to be flat and smooth enough to provide a leak-proof seal.

 

It all sounds simple enough but I would think it somewhat more difficult for the "do-it-yourselfer" to build properly than your design. I haven't aquired any parts yet so I'm likely to change my mind again... We'll see.

 

Looking forward to seeing your completed jars. Thanks for posting the building in progress pictures.

[oldguy]

Hey all you ball mill jar builders.

 

Just FYI the eBay seller below is selling gray flat sheet ¼ inch thick PVC remnants for DIRT cheap prices.

Basically 3lbs for $1.

If you want the pieces ALL cut to a single specific size, the cutting fee is $10, no matter how many pieces that fit in a flat rate single box.

Packaging + UPS ground shipping costs will make you sick.

 

But, if you want-need pieces 12 inch X 12 inch or under.

Those will fit in a $14.95 FLAT RATE large USPS shipping box.

22 ---12X12 sheets ¼ inch thick will fit in a large flat rate USPS box.

Cost + cutting fee + flat rate USPS shipping equals 22 sheets for under $40 TOTAL.

That is less than $2 per sheet that size, if you buy a box full.

 

THAT IS A SUPER BARGAIN

 

Easy to make flat jar ends for 4, 6, 8 or 12 inch PVC pipe ball mill jars with these.

 

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=260754447272

 

The contact person is:

Eric Wasson

IT Administrator

RenoSys Corporation

317-251-0207

Eric's e-mail address is:

admin@renosys.com

 

Edited May 11, 2011 by oldguy

[oldguy]

 

Sheet PVC arrived (22 sheets 1/4 inch thick).

Time to get serious on how best to build these jar ends.

 

So many ways come to mind, its hard to decide.

[oldguy]

Trying various ways to put a BM jar together.

 

I cut 2 X ¼ thick circles to achieve a ½ inch total end thickness on 1 end.

 

Then fit both flush tight together recessed inside the jar 1 inch deep.

 

Then realized if I did that on both ends.

 

It would sure make the jar easy to pick up and/or carry.

 

Because it has a wide lip on both ends

 

Nothing protrudes & you can stand the jar flat on either end.

 

I think I will go that route.

 

Now, I just need to ponder out best how to do the wide access port on the other end.

 

 

One other little thing I realized.

 

Folks make a big to-do about dampening the sound BM jars make.

 

Fact is, 80% of the time my mill & jar or jars will be in a blast bunker.

 

Who cares about a little sound inside a blast bunker?

 

I don't.

 

On top of that.

 

At least if one is using Zirc "M" type milling media.

 

It is easy to tell when the load is about done, from the sound the media makes.

 

With a fresh load, at 1^st you get a slightly rattling tumbling type sound.

 

As the load progress's, it gets quieter & quieter.

 

After a certain time (depending on what you are milling), the load starts to rattle again.

 

At first just slightly, then more & more pronounced.

 

What's going on there is the load has stopped milling & is beginning to cake.

 

If you allow the mill to continue running, you end up with the load caked HARD in the jar.

Edited May 19, 2011 by oldguy