6 replies to this topic

[Freese]

Yeah!!! I am now the proud owner of a real ball mill. The used Thumler tumbler was a waste of money, but at least I can use the 9 pound (yeah, right) container for small batches (you live, you learn).

Armed with my new retort (which has an amazing resemblance to a butter cookie tin), I have blacked some white pine 1x4s (trees are noticable by their absence where I live). Using the 75/15/10 formula, I have made some nice meal, which burn almost as fast as Goex FF (not quite, but close.)

For rocket propellant, does it make any sense to press and/or corn the meal? Since it will be press/rammed into the tube, seems like wasted motion, but who knows (I'm hoping you do and will tell me.)

Should I add some Dextrin? Or will pressing the meal alone hold for a motor grain?

Is there a "good" way to clean the powder that sticks to the media. Rubbing each piece over mesh is way slow and inefficient.

For lift/break, how much difference does it make to press before corning? I still have some Goex left, but that stuff is unobtainium.

Thanks for your input. Now I just need the tooling to arrive (I have stinger tooling, just ordered bp core tool)

Be safe.

[rocket]

With the rocket motors the BP needs to be meal powder then rammed into a single grain. If you used pressed/corned BP in the motor it would most likely cato as the grain would have small gaps in it so the flame would propagate to fast through the grain. As for the dextrin none is needed it the BP will hold its shape fine it rammed well.

[BrightStar]

If you make soft-grained, damp riced BP with little or no binder, the grains will crush easily and consolidate as you press or ram the rocket grain. The big advantage in doing this is that you avoid the mess caused by the dust - my meal BP direct from the mill is almost airfloat and a portion will shoot out of the rocket case each time you insert the drift. I have ended up with BP on my face from trying this before

[Freese]

Well, I made up some Stinger type rockets using the meal powder from my nice, shiny new ball mill. White pine charcoal, 75-15-10. Added 5% Al powder and 5% Ti powder. I was duly impressed by their performance. Hard to say how high they went, because they were almost out of sight (no header for these test runs). Can't wait to see what the core BP rockets will do. Just waiting on the tooling to arrive.

I read a rocket tutorial which gave a 60-30-10 formula. This guys instructions also called for using green meal (no ball mill or CIA processing). He also suggested using 22% 80mesh / 8% airfloat charcaol. I imagine it would never CATO with that type of comp, but what sort of performance can you get with that. I think I'll stick with the 75-15-10 ball milled with airfloat white pine charcaol. I can always cool it with a bit of motor oil if necissary.

Stay Safe!

[Ritual33]

What ball mill did you get mate?

[Freese]

What ball mill did you get mate?

the "small" unit that hobby fireworks makes. Hobby Fireworks

the "small" unit holds a one gallon container easily. I use 29lbs of lead cylinder media I got from him, too (with high antimony content. The cylinder shape give more contact area that the .50 cal. lead ball shot I was using.) The motor turns the barrel easily - I guess around 150 - 200 rpms. MUCH faster then that used Thumler machine I waisted money on. At least I can use that barrel too, for smaller jobs. Yes, I spent far more than I planned on (and much more than I should have or can justify, but what the heck, it should last forever.) Don't let the plywood appearence fool you, it's a well made unit and the top cover keeps the sound down. (It also holds in the heat, which Matt (the maker of the unit) says will make better BP, I just hope it doesn't increase the chance of a "CATO" in the ballmill. ) When Gary sends me the tooling, I'll be all set!

[Ritual33]

LOL, dam, I've been looking for that site for AGES, I thought it went offline ages ago or something. I'm now thinking of getting one of these instead of a tumbler or a professional mill. What ae the barrels like? (I'll send the guy an email but I want a non-bias opinion). How loud would you say these things are? Comparing to say, a washing machine. What are the belts like etc? Any other comments would be great as I might be buying one soon.

Kind Regards,
Drew