Screened black powder for lift.

[Arthur]

Framed and stacking screens come from the gold panning industry. there are usually two (diameter) sizes available and they stack somewhat, lots of mesh sizes are available from 3 mesh to 300 mesh.

 

I made some sieves by using a soldering iron to melt some mesh squares into some stacking plastic kitchen storage boxes leaving one closed to catch fines and using one lid to keep the dust down.

Edited September 8, 2020 by Arthur

[SignalKanboom]

If you find framing screens annoying, you can always melt them into the bottom of a cut off bucket. See here for example: http://bucketscreen.com/ John, the guy who runs it, is great too if you don't feel motivated enough and want to support a pyro friend of mine.

 

That link didnt work, but I went to check it out at least. I enjoy making the tools and supplies I need myself. Sometimes I get tired and have to cut corners. I dont make enough money to buy all the fancy pyro tools.

[rogeryermaw]

google bucketscreen.com

[SignalKanboom]

Once I have made my bp I was going to make a 3 inch shell to lift. I am doing this just to practice. I wont be making any effect in the shell yet. I was going to just make a dummy shell with only rice hulls and bp, spike and paste it, and lift it. Im not going for any effect just successful lift, time fuse, and shell construction. Is there a better way to do this?

Let me know if I should make another thread instead of changing the topic of this one.

[Arthur]

All topics morph with time, some more than others.

 

To test lift, simply launch a ball, A base ball or a cricket ball are fair sizes and weights. Check the powder by timing the flight time from launch to thud into the ground. This needs some free space and a big safety zone for the ball to land.

 

Yes you could launch a blind (no stars) shell but a shell with a charcoal effect may be more work and fun. Many charcoal stars can be made by mixing say 10 mesh, 20 mesh and 40 mesh charcoal into black powder and dampening with a little dextrine water.

[SignalKanboom]

I understand the math, but what about a baseball in relation to lifting a shell. Shouldnt an exact weight be used to get accurate height? Say I wanted my shell to be lower, but the baseball is lighter, or heavier? Is that being too calculated about the whole thing? Ideally I would make a replica and load it with something inert that wouldnt be dangerous when shell broke. That inert material would be equal to the amount of comp that would be used in the future shell, therefore my lift charge could be the exact same. This assumes all the bp be from the same batch and has some consistency( which I will test for).

[Richtee]

that wouldnt be dangerous when shell broke.

Why break it at all? Reuse it. And a baseball’s pretty close to a well packed 3” shell in weight/mass. Even if you overlift a bit, the effect would be the stars “travelling” further upward. Just don’t UNDERLIFT Sure, you can get all precise about it, but I tested, WITH a baseball- EVERY BP lift batch before lifting “active” shells.

Edited September 10, 2020 by Richtee

[Arthur]

Using the same baseball gives you a measure of the power of your powder. -Simply count the seconds! Possibly you are looking for the quantity of powder that gives a flight time over 8 seconds, If the powder is too poor you will get low lifts of only 1 - 4 seconds flight time. Then you go back to the ingredients and process.

 

If you are really fussy you take a sample of every batch of powder and mix faster and slower powders to get perfect consistency from batch to batch, but usually no-one bothers twice!

[SignalKanboom]

Yes, it is about quantity. I tried an experiment a long time ago where I tried to imitate fireworks that used to be sold called thunder kings. It was a small mine, probably 1/2 id tube that shot a colored report. They were decently loud for being a consumer product. I got myself a 1/2 id tube, made a cake style salute, fused it at the bottom, and weighed it. I then made a dummy load filled with salt the exact weight of the salute and tried to lift it with ffg store bought pyrodex. It took a massive amount of that powder to sloppily lob that dummy shell into the air. It produced a weak woosh, Instead of a boom and made lots of smoke.

 

Now I know that was pyrodex, and considering I had very little experience the shell was not as tight in the tube as it probably needed to be. It also weighed 8 grams total. My point is my lift powder requirements (quantity) have always been skewed. I know its 1/10 of the shells weight, but I thought that pyrodex could work at close to those amounts.

Edited September 14, 2020 by SignalKanboom

[SignalKanboom]

I made my ball mill and it came out great, but my sponenburgh jar is slipping on my 1/2 rod stock covered with 1/2 rubber hose. Any ideas?

[justvisiting]

Sometimes the PVC fittings have a flared edge to them that makes them sit less solidly on the rollers. UI filed that edge off. Also, the ruber doesn't grip well if it's dusty of dirty. I would clean the roller rubber well with soapy water and rinse with a damp sponge. It will grab better. Also, I've put duct tape or hockey tape around the fittings to make them grab better. I only had jar slippage with light media like ceramic.

[Carbon796]

Make sure the drum, is rotating in a direction. That loads the weight over the drive roller, and not the idler. Edited September 14, 2020 by Carbon796

[SignalKanboom]

Ok, I came into more scraps and a very large treadmill motor for free. I have my variable speed and ac rectification sorted out. The thing is complete and is spinning a 4 inch x 6 inch spone jar anywhere from 20 rpm to 200 (could go higher, but dont have a need for high speed). I know this is a no no, but it is not tefc. My jar has been water and air pressure tested. I sealed all joints with gasket maker and they are rubber, so I can expect that rubber caps that seal the jar will simply be blown off, instead of the jar bursting.

 

If I unplug the mill before removing the jar and the jar has fail safes such as the rubber end caps sealed with gasket maker instead of a pvc caps sealed with a strong glue, and there is no possibility of leaks, it should be fine to use until I can afford to upgrade to a tefc motor?

[SharkWhisperer]

Holy Moley, you're taking milling safety to a whole new level! New gasket making for every run? Yikes? You'll go through a lotta tubes if you check your progress every couple of hours like many tend to do.

 

Not trying to sound dickish, but following usual and customary safety precautions, like not opening a jar near a potential spark source--not hard to accommodate--if evolving medicine allows it, you will live a thousand years before you have a "jar-opening accident". Personally, I'd be so bored from having risk reduced to the equivalent of "death-by-knitting needle lung perforation when darning socks", that I'd probably rebuild my spin-cans with a fusehole, tsk tsk.

 

You're good, amigo. Live long and prosper (no real question about the first half of that axiom).

 

Really though. Good questions. Forward-thinking mind. Attentive to detail. Careful. Excellent qualities for the hobby. You'll be just fine.

 

p.s. If using rubber-wrapped drive shafts per a way earlier mention, just rough em up with a file and they should grip your jar better than smooth (for a while, at least).

 

Have fun & good pyro experiences to you!

[SignalKanboom]

Thanks shark! No new gaskets for each run. I have a threaded cap that I sealed into a rubber coupler. The threads are sealed with Teflon tape. No dust can escape the jar due to the construction of the jar. I have spent a lot of time reading the posts on this forum and I see a lot of posts stating never to use motors that are not enclosed to protect from the brushes. I never understood that because if no dust escapes until the power is off it is a temj (totally enclosed mill jar) lol. This seems acceptable to me, but still figured I would run it by the pros.

[SharkWhisperer]

Thanks shark! No new gaskets for each run. I have a threaded cap that I sealed into a rubber coupler. The threads are sealed with Teflon tape. No dust can escape the jar due to the construction of the jar. I have spent a lot of time reading the posts on this forum and I see a lot of posts stating never to use motors that are not enclosed to protect from the brushes. I never understood that because if no dust escapes until the power is off it is a temj (totally enclosed mill jar) lol. This seems acceptable to me, but still figured I would run it by the pros.

Smart thinking, and that's the primary point of good pyro practices--you're thinking, questioning, and asking appropriate questions (after researching yourself--spoon feeding rare here). You're cool.

 

Will enjoy seeing videos of your experimentation sometime soon. Don't think they need to be perfect to post them. There's a lot of helpful folks here who appreciate DIY and improvements. Got a cool effect? Post it. Got a questionable effect or one you'd like to improve? Post it. Nobody's gonna rag on you for "failures". They do not exist (unless loss of limbs or significant skin counts--those we don't want to see). We'll help you, and all of us have our own unique strengths. That's what's cool about this forum. Hell, I posted about stars I modified from somebody else's formula and got excellent feedback.

 

You'll never know it all. But you can know a lot. And most develop specialties (rockets, shells, different star comps...). Hell, I'm impressed by a silly well-made fountain!

 

Have fun and the APC family will give good advice and cheer your successes (and almost-successes)!

 

Good folks. Smart folks. Experienced folks and new members alike. Gotta start someplace, and there's essentially endless info available with a few keyboard strokes.

 

Looking forward to seeing your first videos!

[Mumbles]

The TEFC motor on ball mills is definitely a safety consideration, but really more of a secondary one. The powder in a mill SHOULD stay contained. If something happens, like a crack or a top coming loose or something, it's nice to have that extra layer of safety. There has been at least 1 incident that might have been caused by milled powder getting into an electrified motor on a ball mill. For items with open power like star rollers I could absolutely consider it mandatory. In the time being, while a TEFC motor is ideal, an enclosure could help mitigate some risk as well.

 

I would also like to point out that a TEFC motor is kind of a best practical choice sort of thing. They're not impervious to explosion or rated for hazardous environments. Motors designed for those conditions do exist, but are often quite expensive for a hobbyist.

[SignalKanboom]

Ya Im thinking of a plastic liner sealed all around the motor with a hose attached and either covered with a carbon filter, or the hose leading far enough away from the mill jar area (mill area will be cheaply enclosed). The bag Will be supported by the motor mount, a cheap fan will tap into the 110 supplying my rectifier and move just enough air to exchange the air inside the plastic line containing the motor. The air will be pushed out of the hose meaning, Due to the positive pressure outlet being on the jar enclosure side it should push any dust out.

 

This should be crude, but functional due to the small volume of air the motor enclosure contains. Im brainstorming, but I really dont think I need that. I will probably just create a barricade and unplug it based on proximity. My jar is small, and on that note, how much media is required. I have 2.5 lbs it lead balls, which is about 100 1/2 inch balls. My jar size is 4 inch diameter x 6 inch length.

Edited September 24, 2020 by SignalKanboom

[MikeL]

Well crap... I just read the posts about Skylighter's BP kit a few pages up... Since I already have it ordered, should I follow these steps from justvisitings post? I need to learn how to make charcoal anyway... That's what I get for taking a shortcut...

 

 

 

Skylighter's kit could be improved by:

1) Using a better charcoal for BP, like ERC or paulownia.

2) Milling the charcoal

3) Milling the potassium nitrate.

4) Changing the component ratio to maximize the fuel value of the charcoal.

Edited October 21, 2020 by MikeL

[Bourbon]

Make no mistake, Justvisiting, in my book, has some deep wisdom on BP/RP. Well worth hearing out.

 

Even with Skylighters' Coal not being great, you can surely use the rest of those chems. If you follow some of Justvisitings hints you can absolutely make something serviceable with what you have. If you can get better C by cooking it yourself, you will increase you odds significantly.

 

One or 2 times down the BP hole, and you'll see how easy this process really is.

[SignalKanboom]

I just got ahold of some balsa, made some charcoal and then milled it with My sulfur For only 1 hour. I milled my kn03 for an hour separately. I screened both through a 40 mesh one time and the results are astonishing. I have the fastest strongest bp I have ever seen. It is all about the charcoal being made out of soft wood. Finding the softest woods for the best price is the key. It makes a big enough difference you could almost skip ball milling all together.

[Jazzbass5]

Back to the Harbor freight ball mill, I modified mine because I didn't like the plastic bushings and I found the drive motor tended to run a bit warmer then I liked. So, I added a cooling fan and ball bearings to the shafts. I did end up changing the shafts to fit the bearings, they are 3/8s aluminum.

Edited October 26, 2020 by Jazzbass5

[SignalKanboom]

Thats nice jazz, I dont like the price of the harbor freight mill. The speed is not optimized and I am scared of the wearing out stories. I think I will always stick to building one, but it is nice to see someone making it hardier.

[Jazzbass5]

Yeah, I just can't leave anything alone, I probably should have been an engineer. Ha!

[SignalKanboom]

I have that same affliction. If I had to paint a car, I would probably sand all of the paint off of it after I finished spraying and started wet sanding. Edited November 2, 2020 by SignalKanboom