First attempt on shell launch:)

[braddsn]

Visco: Don't worry about that 17lb limit. I had a similar tumbler before I built my big one, it was a Thumler's tumbler, basically the same thing. I loaded it with as much media as I could without overloading the motor. You may not be able to charge the jar to it's optimal capacity, but it will still work fine. When I tried to load mine with the proper amount of media, the motor wouldn't quite turn it, so I had to take media out little by little until the motor could handle it. When I loaded my jar with the chems for black powder, and turned it on, I had to give the jar a push with my hand to get it started, then it ran fine. But it was so heavy that it wouldn't start on it's own. Hopefully that makes sense. Also, if the motor gets too hot, it has thermal protection. So if you walk away and come back later and it has stopped, don't panic. Just unplug it and it will reset. You will figure it out if you are somewhat mechanically inclined. I suggest loading it with as much media as the motor will allow, and making 600g of bp per mill run. You will probably have to run it for 3-4 hours. That's how long I ran mine. And, if/when you decide later to upgrade to a more powerful ball mill, (most likely will be building one), you will definitely use that mill jar. The hex shaped, rubber lined jars are the BEST!

Edited September 25, 2016 by braddsn

[Visco]

I cancelled my order of the rebel 17 and decided to make my own tumbler. Nothing special but I believe it will work. Total cost was about $100.00 since I already had a old 1/4 hp motor. Made a welded steel frame and used some new pillow block bearings with a 1/2 rod covered buy a old rubber air hose with a 6 inch pulley on the end of one and a 2 inch on the motor. Runs a 6 inch pvc pipe at 67 rpm and will handle up to a 18 inch long drum. I milled some charcoal with about 25 lb of cast .495 media I cast from wheel weights and it made the finest charcoal I've ever turned out. I'll try to figure out how to post pictures as soon as I can. Huge step up from the old harbor freight mill i was using. But I have a question about drum construction. I made a drum from a piece of 6" pvc capped one end and on the other I used a 6" fitting with a 6" screw in clean out plug. It worked fine milling the charcoal but a thought came to mind as I was screwing the plug out to dump it. Is their any danger with using the screw in plug milling bp? Will their be to much friction from the threads or static from the threads to cause a problem when opening after milling the bp? Just wanted to get some advice before I give her a whirl.

[OldMarine]

Most use a 6x4 reduce coupling and then use a 5" Fernco rubber cap over the end. I'll post a pic shortly.

Edited October 11, 2016 by OldMarine

[Visco]

The 6" to 4" reducer was what I was going to use but the only place that had one here wanted about $30.00 for the reducer and $10.00 for the rubber cap. I wasn't sure the ball mill I made would work so it was hard for me to pay $40.00 for the reducer and cap. Where as the fitting and screw in cap was $10.00. I was just wondering if there would be any danger in the screw in cap? I did have a problem with charcoal being packed into the gap in the end where the pipe won't seat all the way into the end cap and it was a pain to clean out. So I used some five min epoxy and stuck my arm in the opening while it was turning empty and injected the epoxy in the gap till it was full and level and ran it for about 10 min until fully set up and it solved that problem. Don't know if others have had a problem with that like I did or not but it did work. I guess you could do the same thing using the reducer as long as you epoxied the gap before gluing on the reducer.

[OldMarine]

I'd be wary of twisting that lid off knowing BP had infiltrated the threads and was grinding away as I opened the jar!

[NeighborJ]

$40 seems like a great deal for peace of mind. I do know they sell expandable drain stoppers, which can be inserted into the bald end of the pipe and tightened. You'd probably need to go to a plumbing supply house for those. Threads wear out and will eventually bind, they will also make the milling jar good for only one comp because it's almost impossible to guarantee that you've gotten all the comp out of the threads, even after washing.

[OldMarine]

I tried an expansion type plug and had a problem with it popping out after a half hour or so of milling. Friction heats everything up a bit and thermal expansion pushed it out. The Fernco cap has quite a bit of flex to allow for expansion and contraction.

[NeighborJ]

OM thanks, good to know. It looked like it would've worked great but apparently the real world strikes again.

I use them in a large PVC tube on my welding rig to store my levels. They always seem to end up in the bed, I kept yelling at my helper for not putting it in but now I see that mabe he does? I may owe him an apology.

Or mabe I can drill a small vent hole in the bottom and say nothing, to save my ego.😏

Edited October 12, 2016 by NeighborJ

[OldMarine]

If you can find a thinwall PVC reducer it'll save you a bundle. The fit won't be tight but the cement will fill the gap easily and a little epoxy will slope the joints to prevent corners that hold comp.

 

Now that I think about it, I don't see why a jar couldn't be built from SDR-35 pipe rather than Sch.40.

[chuckufarley]

OM,

 

That SDR-35 is what I used for my jar bodies. The caps and reducer were irrigation fittings (not pressure rated). Not sure of the shedual, but the cap at least has a different shape (flatter end instead of rounded) and was a few bucks cheaper than shedual 40.

 

I don't have alot of time on them yet, but they seem to be holding up just fine so far

[OldMarine]

OM,

 

That SDR-35 is what I used for my jar bodies. The caps and reducer were irrigation fittings (not pressure rated). Not sure of the shedual, but the cap at least has a different shape (flatter end instead of rounded) and was a few bucks cheaper than shedual 40.

 

I don't have alot of time on them yet, but they seem to be holding up just fine so far

Yeah, the caps are flat bottomed on the SDR-35 as a rule as opposed to the dome shape of most SCH-40 fittings and the pipe, though thinner should hold up to many hours of pounding IMHO.

[chuckufarley]

And if they wear out after a few hundred pounds of bp? I won't complain much about spending another $15 on fittings for a new jar

[Wiley]

As others have said, threads are bad. You want a setup like the aged military fellow posted in #28.

[chuckufarley]

I apologize for taking this off topic

[Visco]

I'll be making a new drum tonight. I got a 6" to 4" bell fitting and rubber cap. I'll be making my first run of bp this week with this mill and I'll let everyone know how it does. Thank you all for the information and help.

[Visco]

Hey guys I made my new drum and gave it a run today and have more questions. I set the timer for 6 hours and checked after the run to find two large solid chunks of powder one in the cap end and the other in the neck. Homemade charcoal skylighter KN03 and sulfur. All items seem to be dry. I tested the powder and it's still somewhat subpar I think it must have clumped early in the tumbling process. The only thing I can see is I didn't have enough media in the drum. Not quite half full. Probably needs about five pounds more media which I'll try to cast tomorrow. Any ideas?

[OldMarine]

My powder clumps no matter what I do. I've taken to opening the drum after 2 hours and breaking the plug in the opening up and milling another two hours.

I've tried drying all my chems in the oven etc.. but still get the clumping. There are threads galore on this subject with no definitive answers.

[Mumbles]

I've largely had the same experience as OldMarine. Clumping is prevalent. Drying my nitrate helped, but I suspect my charcoal still held onto some moisture. Drying the nitrate basically reduced the number of times I needed to break up clumps or caking. I was using black willow from Custom Charcoal. The same mixtures with a different charcoal (commercial airfloat) would stay free-flowing without an issue.

 

Some people say that rubber drums can help flex slightly and prevent caking. This never worked for me, but the rubber drum from my Harbor Freight mill did seem to cake less hard. They were different sized drums with different media, so it's really hard to make direct comparisons.

 

If you discover an answer, be sure to let us know.

[OldMarine]

Ned uses the octagonal rubber lined drums and says he still experiences clumping to some degree.

[MadMat]

I notice one thing in your process of granulating your BP. You said you used hot water. I wouldn't do that. You do not want to dissolve the KNO3 when you wet the BP. when the wet granules dry the dissolved KNO3 will recrystallize and the slower it dries the larger the crystals will be (bad!)

I would use room temperature water and add around 20-25% alcohol to it. Adding alcohol will inhibit the solubility of the KNO3. Don't go over 25% though because it will ruin the binding action of the dextrin.

Edited October 24, 2016 by MadMat

[memo]

one thing a lot of people don't think about is drying the inside of there mill and media, I was drying my kno3, my charcoal and my sulfur. I was still having clumping problems. the humidity was high. with drying everything I thought I should have no problems. after 1 batch the bp clumped. the second batch no problem the mill was nice and warm. all the moister had gone into the first batch. this happened several times. after the mill set and got cold and I would run a new batch it would clump. I have a rebel drum and mill a kilo at a time. started drying the drum and lead a long with everything else before the first load and no more clumping problem.

[OldMarine]

I'm going to give that a shot. I've never thrown the media and drum in the drying box.

[NeighborJ]

This idea holds water. Under the right conditions it can take as little as a 15degree temperature variant between air temp and any cool surface temp to cause condensate to form. If the media is 60 and the comp heats as it is milled and reaches 75 then the tiny amount of moisture in the mill will definitely condense to the media causing clumping. I know my mill heats the comp more than 15 degrees so this is entirety feasible to assume this is the cause.

And experiment can prove this by starting out with cold media then warm media, which is what Memo has done.

[Col]

The amount of moisture in the air inside the mill probably wouldnt equate to more than a few grains. I get clumping with the small mill (hdpe jar) but not the big mill (dunlop kart tyre jar).

[Mumbles]

Col, do you think that has anything to do with HDPE being rigid and the kart tire being at least marginally flexible?

 

I've always thought about the moisture inside the jar coming more from remaining BP residue rather than what naturally sticks to the walls of the jar or media. Maybe you're different, but I never really clean out my jar or media when using it strictly for BP or BP-like compositions. It can sit dormant for weeks or months between usage.