Ah, maybe this is a good time to go over some of the engineering design details that apply to tumbling. There is a parameter called 'critical speed'. It is the rpm at which a particle will stick to the inside of the drum just from centrifugal force, and there will be no grinding action at all. This is where your drum goes quiet and for a 4" ID drum, it is above ~110 RPM. To get the best grinding action, you want to maximize ball on ball 'nipping' as this gives you the most extensive grinding action throughout your media volume. You do *not* want the media to free-fall and produce a pounding action, you want rolling and sliding action. 85 RPM is close to ideal for a 4" mill jar. A bit slower is fine, but do not go faster. There is a demo video here: kzfaq.info/get/bejne/gpyjmqqJvb_IdYk.html The Harbor Freight rock tumbler only runs at ~45 rpm, so there is a lot of sliding action, but slower than appropriate for BP. But then, it was made for rocks and meant to run for a week or more at a time. Now, a few words about media: Balls are not ideal for producing powder. They are most appropriate for reducing coarse material to fine. To reduce fine to airfloat dust, a different shape is optimum. You want to adopt techniques that are similar to what is used for grinding paint pigment. Trapezoidal prisms work well because they maximize the contact area for sliding action. I have been using ceramic trapezoids that I got from Winona Van Norman. They list on ebay. (The ceramic media from HF is junk.) I have found that they work nicely in the HF tumbler and their lower density than brass is not a problem since they are still more dense than KNO3. They will just be a little slower and gentler than brass. If you want to use Yellow Brass (and this is a very good choice) get some square stock, either 3/8 or 1/2" and cut the pieces at a bias angle of 45 degrees with a length equal to the side dimension. This gives an effective trapezoid shape that packs much better than cubes or balls, giving greater contact area. Make sure your media has smooth surfaces and edges. If necessary, pre-tumble it with some fine aluminum oxide grit (>100 mesh) until it is nice and smooth. Sharp edges will tear up the inside of your mill jar. Now there is the matter of how to fill your milling jar for best action. You want your media to occupy roughly half of the volume of your jar, not much more or less. Now, and this is important... Add your material that you are grinding so that it only occupies the spaces in the gaps between the media pieces, coming up to just a little less than the volume of the media at the very most. When you shake the powder down into the media, it should not cover the top layer of balls, but should occupy only about 90% or less of the gap space between the media pieces. You can use a batch size much less than this and it will still work fine even down to about 20%. This will give you the best grinding and cutting action in the shortest time. If you use a different fill, it might still work, but might take longer to finish.

I was going to save money and give my kid $5 to run a hand crank and turn the cylinder around like it's a rotisserie for about 12 hours. He's always complaining he wants to make extra money.

You gave me this and I realized I didn't even need to remove the belt/track from my wife's treadmill. I just raised the lower end and placed the mill container on the belt. Works fine.

Awesome, I seen your new mill a couple of episodes ago, best re-purp for a treadmill ever. Brass rod cut into pellets is a good alternative to the balls.

Interesting idea for all the stored expensive clothes hangers that people have.

An observation, take it or leave it: I have heard that plastics (PVC) are hard to detect on X-ray. Heaven forbid the tumbler exploded and PVC shrapnel was an issue. Lead balls will mill great, but you will have a high level of lead in your powder. This will be inhaled with the smoke when shooting. Love your content!

My diy ball mill have O-rings row on the drive shaft. Milling time is around two hours.

Well, that is one superior idea! I was looking for a tumbler with a bigger jar to process some metal parts and the price gap is discouraging. Now I have a treadmill with this rubber trail that makes perfect traction to anything, so I threw a bucket on it and put a stopper roller (a wheel from my kids kick scooter) and voila! No modification needed and I can still use it to loose weight... Thank you for a great tip!

I know Skylighter sells lead milling balls that are harder so that they don't end up wearing each other where it ends up in the powder, but they're almost $60 for 200. Pricing solid brass balls that are 1/2" runs around $15 for 10 so it would be between $250-$300 for 200 in brass, but I agree, brass has ALWAYS been used for black powder. Flasks have been made from brass as far back as the 1800's and they're still making them now because they are non-sparking.

I sprayed my jar and wheels with plasti- dip. Works like a charm

Just in the last month or two I was thinking about the use of lead in the ball mill and that little bits of it would be wearing off into the powder as it tumbles into each other, so that lead would be in the smoke and breathed as your firing, and I do like the smell of black powder, but I like all my brain cells to be lead free, probable I lost enough as a kid when all cars used gas with lead in it.

Very cool ball mill. The other thin that works well to get traction on the jar is a wide rubber band.

Genius. I cast this video from my phone to the TV... And as soon as I saw the treadmill in the video, I looked at the one in our living room... And the wife said, "Don't even think about it." Last batch I made was 4 ozs. I used a brass tea canister I bought online. Chucked it between centers on my lathe and let it tumble for 12 hours with various sizes of lead ball for media. I also found it extremely interesting that you mentioned the lead balls making a dirty powder... It never occurred to me that the lead media might be the cause of dirty powder. Its certainly worth investigating. May have to get some brass ball media myself. Hope all is well. Take care.

I knew that you used one but this is the first time you've shown about it, in-depth. Pretty cool man

That is ingenious. I'm glad you showed this. Praise be given to the 11Bangbang guys to dream this up. I have always thought of harvesting the DC motor from treadmills, but this is thinking outside of the box stuff which makes it cool to me.

That setup rocks, thanks for the tutorial! I use a Rebel 17 that I already had for cleaning brass cases, put a jar inside wrapped in a towel. I had to make a larger motor pulley on my lathe to speed it up some, but the treadmill is a far better way to go with the variable speed motor and plenty of power. Fired .45 ACP cases filled flush with with melted wheel weight lead alloy and roll crimped make fantastic, cheap to free tumbling media. Cylinders are better than spheres in my experience.

Yeah i really need to make one. Keep up the great work brother

Ah, if I only had a welder and knew how to use it… 🙂 Seriously, I've wanted to make my own powder for a while now, but the cost of the equipment has been a prohibiting factor. This is a great option.

EBP, If you wear out the sand paper try skate board tape (grip tape), You know, that gritty tape on skate boards to provide good footing. It's used for other things, too so find the application where it's cheapest (maybe for stair steps or some such thing).

I made a solid one out of an cheap drill press motor with a cooling fan. I mill 4 kgs at a time in a 6" ABS pipe 18" in length works awesome for me.👍

There are also great chinese rotary tumblers like: KD-6808, you can get one for about 47$. I would be afraid to use glass balls in the machine, because it can collect static electricity and cause explosion. BTW I have read that industrially, a least in past big wooden balls were used.

Hi,I use a 12 volt caravan fan ,a ceiling fan not a desk one.,goes the right speed and inner tube bike tires for grip.yes I use brass and bronze ,ground from rod to rounds,took a while ,but have them for ever…am using 4 year seasoned willow…always appreciate your vids ,many thanks.

LOVED that info a tread MILL >!!! who would have thought it? keep up the great work!!!

You could try a rubber bicycle tube pulled over the drive roller

Neat idea! Thanks!

Hi. Excellent idea and very good video. I can tell you that I use hard lead from my .44 cal mould and I run the ball mill only three hours. Then I puck, an all the stuff... The result is perfect for me. I get 2F and 3F.

Instead of sandpaper, you can use grip-tape that skaters use on their skateboards and it works just as well! I'm unsure of the price difference, but something to consider!

i used to use pure nickel as a tumbling media, it came as one inch square pieces that were about 3/16ths inch thick.

i have got a lot of exercise using treadmills, yea my wife has had several over the years and the most exercise that was had using them has been me dragging them in the house and dragging them to their next destination!

been waiting on this video since you teased it the other day. Awesome... Brass media, huh? I'll look into that

I glued rubber inner tube on to the barrel. Gives good grip. I found the black Rebel 17 barrels from a guy NEW at $75 a piece.

Love the Idea! Years ago I found a tread mill and took the motor off for another project, which worked well, the one question I have for you where do you find the tumbler drums for a reasonable cost, the drums I see are replacement drums and they are like 100.00 for a plastic Jar.... If you look at something like PVC the end caps are insanely priced when you get to 5-6" size and of course they are way too smooth inside so you have to glue in bars or something. Does anybody have a source for decent tumbler jars at some reasonable cost?

Still looking for one…i thought maybe i could figur out a way for both losing a few lbs as well as a ball mill…naw! Then i wouldnt get to weld or use other tools…thank you for a more in-depth tutorial! Love your videos!

That's clever..... I scratch built mine using odds and ends. I used 3/8" spindles with 3/4" rubber wheels off an old document transport system pushed on to them. The spindles are on sealed ball races driven by a 1/3 hp motor off an old washing machine. Chassis is 1/2" MDF screwed and glued together, I made it in an afternoon about five years ago. My milling balls are pure linotype metal .69 calibre, and the jar is a plastic drum that has soda blasting medium in it... just the right size. It is coated with a couple of layers of duct tape for wear resistance. No signs of wear yet. Actually, I see no reason why a steel drum would not be OK with either brass or lead balls... nothing to spark in there, and less likely to have static problems in opening. Still meanwhile my plastic drum, is working fine. About 70-90rpm seems about right, making the balls climb up just past the vertical before dripping back on to the powder. I usually mill for about 6 hours or so, but might increase that a fair bit as the longer I mill the faster the powder seems to be. There's some weird stuff happening to those grains in the mill at the atomic level that seems to take time. Did you ever read about the ball mill that used iron filings and very hard steel balls and they milled it for weeks and the properties of the iron flakes after that treatment were astonishing. I think we are seeing similar things in our little mills. The factory at Waltham Abbey in the UK used cast iron wheels n an iron track. The wheels weight several tons and squished the powder grains on the circular track. The process was done dry I believe. The factory used to make all of the powder for the British military, but was destroyed in a explosion many years ago and now, ironically, the British military get their BP from Germany... 😀

you might try cutting a cross section from a motorcycle inner tube , try different size tubes for a stretch fit , i couldn't get replacement belts for my bench top drill press so cross sectioned a car tube ( although i'm told they dont use tubes on retreads no more ) not sure if bikes still use tubes , my WLA does ,thanks for sharing , cheers big ears from down under

5:30 This looks like it can be done WITHOUT a welder... A couple brackets and a metal drill and a cutting disk is all you need for this project. Welder makes for a quicker tidier job, but if you don't have one brackets would do for the joining. Thanks btw, this is a great idea with the treadmill. It's got "mill" right in the name.

Very well mister. You are made excellent.

this is great. I have never seen anyone else make a treadmill ball mill before. I 3d printed a mount to move the roller forward so there was no welding involved. I also changed the original motor controller out. it would quit after 1 hour. The easiest solution is to just use a 12v 3a+ power supply. it runs at 78rpm and fits 2 mill jars totaling 4lbs of powder. as for milling media, I cast my own range scrap into balls. the grip issue on the rollers was fixed by putting a grippy rubber tape on the mill jar. it never slips and it made it slightly more quiet.

I used a treadmill as a big tumbler on a 1gal pickle jar. I just clamped a 2x4 across that deck. Then just set the jar on the belt and the 2x4 keeps it rolling.

If you load the Rebel 17 drum with the proper and correct 30 pounds of shot, the stock drive WILL NOT WORK. Too much weight for the motor and drive band. I use a custom drive. 1/2" rollers on pillow block bearings from Ace. I use a HF 1hp motor. Turns 80 RPM. It will process 1000 grams of white cedar, spruce or black willow composition in 1 hour. Nice that it doubles for case tumbling. Two birds, one rock. Welcome to the high efficiency club.

hey Jale what about putting some of that flex seal sheeting on the roller? or maybe some electrical splicing tape? the splicing tape is natural rubber and will seal to itself i use it on handles a lot! you know if you could find some hard enough river rocks might work too?

Those treadmills are a dime a dozen on trash day in Los Angeles.

It was great to see another video from you, I went through your channel and watched/liked all the videos so I was really looking forward to another one! Also my wife loves your end to the videos, she was walking through the living room and heard you say the "if you didn't like it well then go make your own damn video" and started laughing saying "I like that guy" 😂 she normally has no interest in stuff I watch but even she enjoys your videos so keep it up and post more junk for us. 💪 Maybe black powder shells in a modern shotgun?

There are times i wished i did not find your channel, Ha. Saw this video last night, now today i am the proud owner of a used WESLO CADENCE. G 5.9 treadmill, low miles like new. It was 30 mins from the house and was $50. Found on facebook marketplace. Speed does adjust to 1.7 as well, ha. The frame is perfect for the mod and the free spool roller is also adjustable for perfect alignment. Soon i will have a super duty bluetooth controlled tumbler, Ha. So much fun!!!! Thanks for the tip!

Did you cut the upper section down? Seems like a big unit to have sitting around just to mill powder but I like the idea. I still gotta make the PVC milling container. This summer I'll get to it. I just keep playing with it here and there, thanks for doing all the work so we can just copy cat!

You can buy a single phase speed control. We used one on a drill infinite speed control.

LOL, I dont think my wife would let me cut up her $1500 treadmill.

I don't have any more room for junk but I have plenty of time at work, so I'm just going to stick with the other one. I'm going to pick one up today.

Great idea

I do make my own BP propellant... I do have a treadmill in the "junk pile"... I'm watching the video now!

The commercial mill I saw was steel. I never saw it in operation. They stopped it to add about a ton of charcoal and sulfur 3:2 mix through a large side door. Holes on one end let hot air in. The other sucked out the dust. Only the fine dust was kept and coarse material was put back in with the cannon balls. I never heard 3" cast iron cannon balls in a steel drum. It isn't something that you could mimic in a residential area. But it mixed the two parts together before blending with wet potassium. Slurry was made by weighing an amount dry then pulverizing it with steam. The slurry was mixed with the dust using air. That dough was augered to the puck press. As with many plants, one day, it burned. They never rebuilt in Woodinville. Too many houses in the 80's were moving in. There was an underground rocket fuel plant right next door. What genius did that?

Good idea . Save myself about £50 of my English pounds too 👍 by the way can you use a manual coffee grinder to grind up your pucks or are the meats grinders the better option

I see these on the side of the road all the time

Finally a use for a treadmill.

Liked your Ball Mill so Much I made my own Damn Ball Mill. Too bad I can't add Photos to this comment, Oh well Mine still needs some tweaking but I am on track. Thanks for your video

Did some checking and returned with some info. It might be cheaper and easier to use a "Universal" motor (an induction motor wont work) and a Triac or SCR speed controller. That is how your tread mill does it, just like your electric drill or any other variable speed tool. BTW, Not sure where you could get one but I have a 1/3 HP CVT drive for a small lathe given me by an uncle from the late 40's. (From size/shape of the "box" Im sure its not like a CVT auto tranny- input/output shafts are 90deg to one another.)

Thanks for sharing

Your talk of ball mill speed reminds me of operating a 600 ton an hour gold mill

I bet some vacuum cleaner belts stretched over the ends of the jar would provide all the traction you would need .

I'm betting the photo of the Civil War Cannon behind your left shoulder was taken in Gettysburg......As for the newest video, I now have a use for the treadmill currently sitting idle in our basement! Innovative idea!!

I tried the brass thing, No "Workie 4 Me". Reproduction propel go booooomm and was dirty. ceramics In Ceramics (glass Costco green olive jar) solved "My" ceramic balls not balling, Gave my media a Hammer and Anvil with hard on hard. but I have driven past a few Un Homed tread mills at a curb. I LIKE IT! "I Was" CHEAP, NOW "I Am" GREEN!!

One more note about chemicals for making BP. I have found by direct testing that potassium nitrate does *not* absorb water beyond trace amounts. I determined this by leaving KNO3 powder in a dish exposed to ambient air for several days, weighing it, then heating it to 100 C for 24 hours in a lab oven and re-weighing. It lost less than 0.5% of its original weight. In contrast, testing charcoal in the same way showed that it loses ~5% of its weight from loss of adsorbed water. The charcoal recovers this 5% water weight when re-exposed to room temperature ambient air. Charcoal gains water weight from the air, KNO3 does not. It is possible that the weight of the water adsorbed by charcoal should be accounted for (test your own supply) when weighing out your ingredients for BP.

Too cool

Critical speed of a ball mill is the point where as the mill is sped up, the contents no longer begin falling as they reach 12 o'clock. This is also the speed at which the mill stops making noise. Taking the mill to this critical speed and then back to 75% of this speed will be about correct. You can see this in a windowed clothes dryer. If you can tumble briefly with media but no powder present, tumble without the cap on the jar. The media should remain on the walls until about 45 degrees before vertical which should also be about 75% critical speed.

I do have a Thumbler's Tumbler that I use to wet clean brass. Being I have this, would you still recommend the treadmill ball mill? Also, what is the ratio of brass balls to XX weight of powder do you recommend? I'm thinking I would do 8oz powder at a time. Thanks for a great video!

I've shot peened rollers in the past which helps with traction.

Cheap bicycle innertube super glued to the tub will give you grip.

I want to do this to.make a rock polisher

I am using only hand ball mill from plastic Jar and some lead media and guess what, it works but You need to shake it and stirr it :)

It looked like you had glass marbles in with your lead balls. I’ve used just marbles to make flash powder with success, do you think they would work in this application? I just subbed, love your channel👍

If the women don't find you handsome... they should at least find you handy! Nice work!

OK, one thing, how did you make your PVC ball mill jar. It looks like you've kept it simple.I like simple so I'm hoping you can make a simple video on how to do it! Also, I really liked your new "better than Swiss" video, great job!! I was glad to see you recommend using 1/2" brass balls instead of lead, since lead is easily abraded... Anyway, not being that handy, I'd like to hear how you made your ball mill jar, PVC glue, caps, end closure, etc.

I haven't tried making powder as of yet. He stated that using lead balls makes for dirty powder. What if you used powder coated lead balls? Would that make for a cleaner milling process? Just curious.

Thank you for another great video. I was wondering if you knew the hardness of the LED balls that you were using? I was thinking that if you had really hard cast LED balls it might not be as dirty

Can you use a rock tumbler? Even if it takes a week or longer…thanks!

Rubber bands? Greetings from Poland, another side of Earth!

Is it possible/advisable to use stainless steel balls rather than brass, or is there a conductivity problem with these? Chris B.

So, If I have a treadmill that just happens to be the wife's main exerciser, and I have no welding skills, mounting the jar on a wooden frame suspended over the treadmill track, with adjustments for downward pressure on the jar, am I goods to go?

Nice, and I make my own videos Taurus Hipoint enthusiast

Couldnt you just melt some lead and pour it into Brass cases and then squeeze the end of the case with a vice to keep the lead inside ?

nice

Depending on your ball mill jar. You could maybe get at least two if not 3 ball mill jars on it and increase your production

If you are going to use all that electricity, why not have a much bigger container to process more at a time? Thanks for the video.

Yes!!!

Is aluminum a safe alternative to brass? Talking of course about sparks.

Sounds like making this...took a set of big brass balls...

Wow, that mill was spinning fast. Is the media going to still be able to do its work???

Hi Jake, just wondering what size brass ball media that you use and how many?

I knew you used sandpaper right before you said it

I cast a bunch of lead balls at 28BHN so there isnt as much contamination. What are your thoughts on milling in PVC vs ABS? I've read that PVC can build static but ABS doesnt so I've just been using ABS pipe for milling. I've been searching for an old treadmill for months to do the same but happy with this big rock tumbler I've been using for years. What about a rubber hose to sleeve over the rollers? I bet something close to under ID and heating up you could slip on.

I still think you should use powder-coated lead balls.

What if you removed the back roller, hung the upper portion, and put the container inside the tread?

I think rubber band or rubber tape would work on your cylinder?

I take you can't use a vibratory case cleaner because of the plastic container (Kaboom) is that correct?

Cut some water cycle inner tube put them over that pipe for tires

When you were using lead what caliber balls were you using?

Have you ever ball milled your powder and it forms a solid clump in the ball mill? I have had little clumps before, but yesterday it formed a solid brick in the bottom, and I have no idea what's going on...

🥓👍⬆️

How 'bout powder coated lead balls?

I was wondering where you got your brass balls?