built myself a ball mill

[saluterocket]

i have been using a harbor freight tumbler and am tired of being limited to 200 gram bp batches, this new mill i built can do jars that weigh 10 pounds easily. the video shows the mill before the lid under the rollers was installed as well as the other side board; this is to show how the internals work. the specs areas follows.

 

16" high

24" long

1.35" diameter rollers

1735 rpm continuous duty GE motor

1.5 inch pulley

7.5 inch pulley (to controll roller speed)

all constructed with 3/4 inch laminated particle board

barrel od 6.5"

 

speeds (all speeds were calculated before hand using passfire and the calculations turned out to be correct or at least very very close)

 

motor speed 1735 rpm

pulley 1- 1.5 inch

puller 2- 7.5 "

roller diameter- 1.35 inch

barrel od-6.5"

 

barrel speed = 73.96 rpm

 

because of this set up my ball mill gets the optimal rpm and is very effictent (powdered 5lbs of kno3 in 30 minutes to the consistensy of powdered sugar) here is a VIDEO Note- in the video the construction of the ball mill is incomplete, but it is still able to run in this condition.

 

http://media.putfile.com/ballmillvideo

[Frozentech]

Nice one. Very similar to the Sponenburgh design. One thing ( and you perhaps did this already ) I would add is a flat shelf area under the rollers, just in case a jar popped open ( has happened once to me ). If milled BP dust fell in your motor it might not be a good thing

 

What media do you use ?

 

Again, nice job.

 

[edit] ok, you called it a lid under the rollers, but same effect. Something to shield the motor.

 

I can't recall if I ever posted a pic of my mill here, I will dig one up and post it later.

[Doubl3_HeLiX]

Very nice mill. How much did that motor cost you, and where did you get it? I have been planning to build a ball mill for a while now, I just need a suitable motor.

[saluterocket]

The motor was from ebay, it was about 30 bucks,

 

as for a lid, i added one since the video was filmed, i know about how motors and not mix.

 

 

total cost was about 50 dollars (i already had the wood)

 

as for media, i will be casting my own Linotype lead media, right now i only have marbles (for powdering chems), so it no bp until i get the lead media.

[ewest]

Ok, I finally outgrew my Lortone rock tumbler and had to break down and get a new ball mill. So being the genius I am I figure "Hey, I'll just build one, how expensive can it be?" Well, when I'm doing it apparently VERY expensive. I'll bet I've spent easily $400 on all the parts and crap. Anyway here you go:

 

1/2"HP 1725 RPM Capacitor start motor

2" Pulley on Motor

5" Pulley on 5/8"OD steel rod roller

5/8"OD steel rod with 5/8"IDx3/4"OD heater hose for roller

 

6" Sewer Pipe PVC Jar

11 1/2" total length x 6 5/8"OD

about 1 gallon capacity

1/2"ODx1/2"LG Hardened Lead Media

 

I used the Passfire calculator and I was shooting for an optimal RPM of 73.57 and I was able to get it actually running at 78.11 RPM

 

Whole thing is 2' tall x 1'-9" wide x 13" deep

 

I still have to put the lid on and put the motor access panel back on but at least I can use it now.

 

Jar & Media

Cord & On Switch

Motor & Wiring

Top View With Jar

Top View With Jar

Ball Mill Video

Finished Mill

[FrankRizzo]

Since you've got woodworking tools, you can save a ton of money in PVC fittings by making your own endcaps for your mill jars ala Passfire. Additionally, you won't have a dead area in the neck of the PVC reducing coupling.

[ewest]

I saw those on passfire where he cuts round plugs from wood. But it looked like those would pop open unless you sealed it with a bike tube and duct taped the whole thing shut. I thought the Sponen jar would be easier for me, especially at first.

 

If it isn't working out with my jar I certainly can go back and make the other ones seeing as I have 5' of green PVC sewer pipe now.

 

Frozentech mentioned the other day that he uses Thumler jars for his mill. That's an option too.

 

I need to quiet this thing down though, it's really noisy. Anyone have any ideas? I thought of glueing pieces of outdoor carpet to the inside, or styrofoam boards. But I'm a little worried about a static charge from that. Anyone think pieces of cardboard lining the inside walls might work?

[optimus]

http://www.soundprooffoam.com/

 

Failing that, egg boxes are a popular choice for 'ghetto' soundproofing ; )

[Mumbles]

There is a mill jar made by Pretty Green Flames I think from this forum. It is similar to the passfire end caps. I personally don't like how he (passfire) screws them in. seems like a huge pain in the ass. PGF extended the outer disk out about an inch or so, and just put some threaded rod on both sides through to hold them on by way of wing nuts or something similar. I think he was reading my mind when designed this. That was my plan for a while.

 

Alternatively, placing a vacuum cleaner belt over the jar the long way may be acceptable, perhaps with 2 more belts over the initial belt to keep bouncing to a minimum and provide traction.

[pyro4life]

Got my new mill/star roller made thought id share the vid if anyone was interested. Its nothing special but it rolls stars and mills black powder and comp in no time, its not finished yet but its running just need a rubber belt and a stepped pulley! Cost so far is about 30 quid.

 

VID: http://youtube.com/watch?v=gAl9t68auLs

 

BTW hair dryer is new (to me anyway) way iv found for drying stars, just leave them rolling and shoot warm air through them!

[asilentbob]

I use a 15lb Thumler tumbler as my mill and yes the jars are very nice. I would actually get another one if they were priced a bit cheaper.

[tentacles]

I've put some finishing touches on my mill - here's some pics:

 

http://www.apcforum.net/files/DCP_1.JPG

http://www.apcforum.net/files/DCP_2.JPG

 

The motor came from a local surplus store, it has a gearbox and turns 145 RPM with plenty of torque for the job. The pulley on the motor is a clear plastic caster wheel (also surplus store) that I cut the rubber off of - it has a perfect groove to drive the Giant O-Ring belt. It's actually pretty quiet in the cooler with the lid closed.. If I put a pillowcase between the lid and the cooler, it's almost inaudible.

 

I also picked up a #5 meat grinder there for $7 - I've used it to grind up some Mg shavings and it does a pretty good job. It's absolute magic on magnalium, though - toss in small egg sized pieces and it turns them into a nice powder...

 

http://www.apcforum.net/files/DCP_2375.JPG

[Polumna]

hi all

 

 

I have built my ball mill from lego and it did

a very good job for my 500g of blackpowder.

 

Here is a video of it in action:

 

http://www.youtube.com/watch?v=WvhE4WC6Oa8

 

Polumna

[mormanman]

Does anyone know (I haven't gotten one yet but soon I will) if one can change one of these to mill 3,4,5 plus jars at once? If you can can you tell me or direct me in the right direction.

Thanks

[Mumbles]

Yeah, I suppose with a little work and ingenuity it could be modified to turn multiple barrels at once. You'd have to cut the end off, and replace the drive rod with a longer one. It looks to be approximatly 1/2" on mine. You could probably use the end you cut off to hold the longer bars by mounting the whole thing on a sheet of plywood.

 

4" PVC could be used to make the additional barrels.

 

Now, this is how you COULD modify it. I'm not saying that the motor could handle it, though it seems that it probably could.

[mormanman]

Yeah, I suppose with a little work and ingenuity it could be modified to turn multiple barrels at once. You'd have to cut the end off, and replace the drive rod with a longer one. It looks to be approximatly 1/2" on mine. You could probably use the end you cut off to hold the longer bars by mounting the whole thing on a sheet of plywood.

 

4" PVC could be used to make the additional barrels.

 

Now, this is how you COULD modify it. I'm not saying that the motor could handle it, though it seems that it probably could.

Wow, that sound like fun maybe if I get one now and another for my birthday I could try something.

[qwezxc12]

Well, I finally got tired of flogging my hacked up abomination of a Lortone 33A tumbler along, so I just finished building a slightly more serious Ball Mill.

 

I really like the Lortone jar design, so I picked up 6lb. and 12 lb. jars; they're both 7.5" OD and have an octagonal interior, so lifter bars are not needed. The 6 and 12 lb designations refer to rock capacity, I guess... I don't have enough media for the 12lb jar yet, but the 6 lb is ready to go. Based on a proper powder charge, I'm guessing the smaller of the two barrels will mill 500 - 700g of BP at a whack.

 

I borrowed from some Passfire ideas, like the gravity tensioned belt. The motor is a 1/2hp, pulley's are 2.25" and 6", and the drive is a 5/8" shaft with 3/4" hose. The idler is a 2" OD ball-bearing conveyer roller. The frame is assembled with my two favorite friends: Deckmate screws and Gorilla Glue. I still need to add caster rollers at each end of the barrel trough to keep the milling barrels from wandering.

 

The big jars turn @ 71 rpm...just about optimal for their ID and 1/2" media size. I left room for another idler roller; I will be able to use my two small 4.5" OD Lortone barrels for smaller milling jobs. When swapping barrels, I'll swap the motor side drive pulley to a smaller one to keep the smaller barrel to 90rpm or so. The gravity tension will make that a snap; all I need is the allen key for the pulley set screw.

 

Top:

http://www.apcforum.net/files/Ballmilltop.jpg

 

Front:

http://www.apcforum.net/files/Ballmillfront.jpg

 

Back:

http://www.apcforum.net/files/BallMillback.jpg

 

Future idler roller for small barrels:

http://www.apcforum.net/files/futuremods.jpg

[tentacles]

Instead of changing the pulleys when you want to use the smaller barrels, find a two-step pulley for your motor (or the barrel) and just move the belt over - the gravity tension makes this a perfect setup. I'd suggest doing it on the motor shaft, as there will be plenty of room for the belt to move sideways.

 

I'm amazed you are able to fit 500g of BP in the 6lb jar; it seems too small for me (but then I've been using balsa charcoal lately). My jar is about 6.25" ID and about 11" IL and I figure I could do about 800g batch, but I've only done a 600g batch so far.

[qwezxc12]

500g seems to be the proper charge for the smaller of the two. The barrel is 3 5/8”deep x 6.75 ID; the larger is 7 1/2” deep, same ID. The media I use are 335grain .50cal FMJ pistol bullets - the smaller barrel is filled about 1/2 way with 300 of them, so ~14 lbs. of media. The 500g charge of BP seems to fill the barrel up around 3/4 the way, when using ground up Cowboy charcoal as a starting point. I'm certain it's not as fluffy as Balsa.

 

I just ordered 23 more lbs. of media, so the big barrel will be rockin' soon.

 

As far as the multi-step pulley, I originally looked and couldn't find what I thought would be the proper sized double motor pulley at McMaster-Carr. However, after checking the barrel rpms with a piece of tape and a stopwatch, my motor would seem to be turning closer to 2000rpm, than 1730.

 

(I used the Passfire calculator and assumed actual pulley diameter, rather than nominal, i.e., an "A" cross-section 6" OD pulley, actually has an effective diameter of 5.75")

 

I need to re-check my numbers with the assumed motor speed and see what I come up with.

[FrankRizzo]

I used that smaller barrel on the Lortone QT6 (my first "milling experience), and could only effectively put 350g in there per run. I was using Paulownia airfloat though, so if you're using denser commercial charcoal you may be able to squeeze in 500g.

[mormanman]

Yeah, I suppose with a little work and ingenuity it could be modified to turn multiple barrels at once. You'd have to cut the end off, and replace the drive rod with a longer one. It looks to be approximatly 1/2" on mine. You could probably use the end you cut off to hold the longer bars by mounting the whole thing on a sheet of plywood.

 

4" PVC could be used to make the additional barrels.

 

Now, this is how you COULD modify it. I'm not saying that the motor could handle it, though it seems that it probably could.

Hey remember this (I'm not blaming) well yeah I tried something like it and so I attached the big pulley to the motor and the little pulley for the one to spin the shaft. Guess what I cut a big hole it the side to fit the big pulley on the motor and the big pulley spun just fine but the little pulley wouldn't even move the hole thing locked up so I had to put it all back together. The motor is for speed not power (I think).

Maybe someone can tell me how to boost the power for the motor?

Any suggestion, I willing to try (if logical).

[qwezxc12]

Yeah, I suppose with a little work and ingenuity it could be modified to turn multiple barrels at once.  You'd have to cut the end off, and replace the drive rod with a longer one.  It looks to be approximatly 1/2" on mine.  You could probably use the end you cut off to hold the longer bars by mounting the whole thing on a sheet of plywood. 

 

4" PVC could be used to make the additional barrels.

 

Now, this is how you COULD modify it.  I'm not saying that the motor could handle it, though it seems that it probably could.

Hey remember this (I'm not blaming) well yeah I tried something like it and so I attached the big pulley to the motor and the little pulley for the one to spin the shaft. Guess what I cut a big hole it the side to fit the big pulley on the motor and the big pulley spun just fine but the little pulley wouldn't even move the hole thing locked up so I had to put it all back together. The motor is for speed not power (I think).

Maybe someone can tell me how to boost the power for the motor?

Any suggestion, I willing to try (if logical).

The small hobby rock polisher / tumbler motors do not have sufficient torque to drive much weight. I do not think you'll have much success adding additional barrels.

 

The best I could do with my Lortone 33A - dual barrel model (which might have a better motor than the Harbor Freight equivelentl) was to slot the motor mounting holes, to increase the belt tension and add rubber hose to the drive shaft, increasing the barrel speed slightly.

 

I couldn't drive more than one barrel half filled with media and charged with 300g of comp. If I added more, the belt would start to slip. Increasing the rotation speed with the hose helped a lot with BP meal quality.

[frogy]

This seems to be the most relevant thread to post my Ball mill under without starting a new thread and getting yelled at by mumbles =)...

 

so here...

 

If you rather just go to a website where it has them all on 1 page with a video... Here is my web site if it's up...

 

http://frogy.is-a-geek.com/pyro/ballmill.php

 

 

Empty Jar

Jar with Media

Side of Jar

Front of Mill

Back of Mill

Top of Mill

Nailed Idle Wheel

 

The Nailed Idle Wheel was nailed to keep the jar from drifting so much it would roll itself off...

 

The jar is 4" ID DWV-PVC... The caps are called "Test Caps"... they're easily removable, but fit snugly...

 

The wheels are from a push mower or something... they are 7.75" OD...

 

The motor was used for pumping oil... It's 1/10th HP, geared down to 60 rpm (it has tons off torque)

 

The motor has a 5/8" shaft direct drive to a 1/2" printer rod (stainless steel I believe)... 60 rpm to a 7.75" OD Wheel to a 4.6" OD Jar (with rubber) = about 101 rpm...

 

The optimal speed for my .53" lead media is close to 110 rpm, so my mill is pretty efficient...

 

The rubber I used is used in airplanes for rubber flooring for isles, under seats, and under carpet... (step dad works at aircraft interior plant)

[mormanman]

Ok, anything electronic is way beyond my understanding of anything. I have no clue what is going on in an electric motor other than you plug it in the wall, flip the switch and it moves.

 

I have a washing machine motor very similar to exactly like the one Dan Williams uses. LINK. How can I take the panel of the entire thing and make run through one switch like Dan Williams?

 

I tried to night (I was hooked to a computer breaker and made the break flip several times) I burned the link to the switch but I'm not sure if the switch is burnt or not.

 

I would be very thankful for anyone's advice/help.

[FrankRizzo]

You need to interrupt the "hot" side of the wiring with a switch. If you look at a normal grounded outlet (in the US anyway), with the ground connection at the bottom, the right side (slightly smaller slot) is the usually the "hot" side. If looking at modern house wiring, the black wire is the "hot" wire, whereas the white is neutral, and the bare copper (or green) is the ground.

 

http://www.pyrobin.com/files/switch%20wiring2.gif

 

The motor may also require a starting capacitor, might be broken (shorted), or may require a different voltage. Post a picture of the motor, showing the label if you can.