Powder die and Corning machine

[bmarley5780]

Hey guys/girls

 

I have bought a 2ft section of ABS pipe to make a 3" powder die.

 

I am using Dan William site as a reference point. But from lookin at the pictures, nd the little throw togather job I did yesterday some questions/problems arise...

 

-My question concerns the compression sleeves-

 

I know you need to cut slits into the inner and the outter sleeves, but how does this work. I did the same thing as on his site but it took some work getting them around each other. Once on, the outter sleeve along the slit was probably seperated 1 to 1.5 inches. I look on Dans site and do not notice this??????

 

???Dont get it???

[ULTRABUF]

If you used a piece of 3" pipe for your outer sleeve, this could be the problem. You should use a repair coupling like he did, or if like me you cant find that use a normal coupling and grind the ridge in the middle out.

[pudidotdk]

As Ultrabuf said, use a repair coupling. The outer sleeve should fit over the inner sleeve, even when not cut.

http://pyrotechnics.no-ip.org/files/die.jpg

[bmarley5780]

Damn-

 

I just looked at that "repair coupling" as if it was another piece of 3" pipe. ekkk

 

Nice drawing pudidotdk!

[qwezxc12]

If it helps, I use a piece of 2.5 schedule 10 SS pipe and a cylinder of HDPE. I bought a little over a foot of each and trimmed it into two 6" sections. I use one for a 3" comet pump, and the other for my powder die.

 

Pics and details here

[bmarley5780]

I see-

 

SS- ? I see them and I think of stainless steel? Am I right?

 

I have been looking on EBAY and have seen a guy that sells 5-7 pieces of 1 ft pieces of aluminum for 15 bucks or so....All pieces are verious diameter. Might go that route.

 

Tryin to make some ChryXXXXXX 6 cut stars right now. . . wish me luck.

 

-Peace

[psyco_1322]

Why does everyone use C-6? Its slower than C-8 right? If it is I might change over. My C-8 is a bit fast. A comet of it burns out before apogee.

[bmarley5780]

I don't see why you would care about who does want, and when.

[Mumbles]

In some cases a faster star is ideal. If the comets are burning out before apogee, use less lift by the way.

 

Anyway, HDPE probably isn't the ideal material for comets. Sorry to say it. For the same reasons it is a good mortar, it is a poor rammer. Namely it's compressable and stretches, which will make it hard to machine if you wanted a core, and it won't put quite as much pressure on the comp. I might be worried about it bowing out and siezing against the outer sleeve, and not pressing as much. If it works for you though, more power to you. If I were going to get a set of tooling, I would buy Aluminum though.

[FrankRizzo]

Nylon, Nylatrol, or PVC rod also work very well for powder dies.

[qwezxc12]

...Anyway, HDPE probably isn't the ideal material for comets.  Sorry to say it.  For the same reasons it is a good mortar, it is a poor rammer.  Namely it's compressable and stretches, which will make it hard to machine if you wanted a core, and it won't put quite as much pressure on the comp.  I might be worried about it bowing out and siezing against the outer sleeve, and not pressing as much.  If it works for you though, more power to you.  If I were going to get a set of tooling, I would buy Aluminum though.

Well it works in my 6-ton bottle jack press just fine. I pressed those 3in 300g comets 'till the press groaned and the rammer took it like a champ.

http://www.apcforum.net/files/3incometsPasted.jpg

I'm not sure how much compression you would need to bring to bear on Ultra High Molecular Weight PE to make a solid 3in cylinder deform, but it's more than my press will do. Solid Al bar stock was a little too spendy for 3in OD (for me at least)

 

The jury is still out on machining, though. I just got a couple feet of 1/2" brass rod for making cored comets, so I'll be drilling out the rammer soon.

[FrankRizzo]

A local tree spade mfg firm that one of buddies works for uses UMHW for the inner lining of the tracks that the blades ride down as they press into the ground. These tracks are subject to extreme amounts of hydraulic thrust load without any problems. Machining is also quite easy with UMHW, Nylatron, or Erdalite engineered plastics.

[Bonny]

For my powder die I use 3" ABS pipe with only hose clamps for re-enforcement, no sleeve. I use a 12ton bottle jack in my press. I give it almost full pressure,enough that my press top bar (approx 12" long pc of 2" heavy wall steel sq. tube) is starting to bend. My rammers are UHMW (polyethylene) about 1" thick. To remove, I press BP puck out into another pc of 3" ABS that is cut down one side.

[bmarley5780]

I think I might get to mine tonight.

 

-I am goin to follow Dan's site, maybe not striaght to the tee, but pretty close.

-I have alot of polyester tooling resin leftover from a fiberglass job I did awhile ago.

 

Question on using sand in the mix for the rammers. Would regular "play sand" work ? USA people can get at Lowes/H.D.

Its bleached, cleaned and pretty fine...???

[tentacles]

It might work, but it won't be nearly as strong as the silica sand would be.. The shape of silica sand is square, so it adds a lot of strength to the resin. A lot of hardware stores sell it as blasting sand. Craft stores sometimes sell colored versions of it for sand art.

 

In my limited experience some charcoals act a bit differently, too. I have to press my balsa BP for a few minutes, it packs down slowly but it will get to the right density. The commercial airfloat BP I made a while back pressed right down and didn't expand back out, something the balsa BP does. Strangely it doesn't really require a whole lot of pressure to compress, but it will not compress quickly. I have not tried a batch with the red alder charcoal yet, but I imagine it would behave normally.

[bmarley5780]

ahhhhh- I see-

 

Well that tooling resin is supposed to be harder/stronger then regular polyester, will probably throw in some 4oz. chopped strand mat in there as well. Should make up the difference.

 

-Peace

[andyboy]

In my limited experience some charcoals act a bit differently, too. I have to press my balsa BP for a few minutes, it packs down slowly but it will get to the right density.

I always press the pucks and let them "rest" for a while before I let the pressure of them. If I press them all the way down I can't seem to compress them as much as I can when I let them rest, then continue pressing and let them rest again before I let them out of the sleeve. Sorry for beeing incoherent but I was just on a three day trip to see lions and bears and stuff with my family... Rambling... Sorry... So tired... Zzz...

[bmarley5780]

Hey guys!

 

A few quick questions.

 

-Do you guys add Dextrin to the comp. when pressing?

 

-On Mr. Williams(not sure if that is right). He states that for a 4oz. batch uses 4g of a water/alcohol solution to get it damp. Says that the whole mixture will become a "slury" if you will....Um, there is still airfloat powder goin everywhere with only 4grams of water in it!

 

-Joe

[Bonny]

Hey guys!

 

A few quick questions.

 

-Do you guys add Dextrin to the comp. when pressing?

 

-On Mr. Williams(not sure if that is right). He states that for a 4oz. batch uses 4g of a water/alcohol solution to get it damp.  Says that the whole mixture will become a "slury" if you will....Um, there is still airfloat powder goin everywhere with only 4grams of water in it!

 

-Joe

I'm sure some people add dextrin, but if you are pressing I don't think you need it. I used to do 2" pucks with a 6 ton bottle jack. I moved up to 3" die when I got a 12ton jack. I add + 10% water (water is roughly 1g per ml). I don't think it should be wet enough to really call slurry...I press it as hard as jack will handle, wait 10 min or so and press again. Wait another 10 min or whatever and remove.You might have some water leaking out of the die, but it's never been a problem for me.

 

Oh yeah, I have no idea whay density it is. Never bothered to calculate. Once broken up it works great.

[bmarley5780]

Bonny-

 

Thanks for the quick reply.

 

I tried to see if you had any videos of yuor BP or lift and it seems that your have not posted any. Not doubting your skills but does your pressed BP/lift perform very well? Again not doubting you! )

 

I too have a 3" die that I am using. But only with a 6 ton jack. I dont think that would make to much of a difference. Do you?

 

So when you press, do you use 119 grams of powder? What if not? Or do you just add 10% to any amount that you are pressing?

 

I have probably 200 grams of lift that I am wanting to press tonight ) Also, on a side note do you use the common BP ratio for lifting shells or the lift ratio 74:14:12 (could be wrong on that ratio, dont have my note in front of me now).

 

-Joe

[Bonny]

Bonny-

 

Thanks for the quick reply.

 

I tried to see if you had any videos of yuor BP or lift and it seems that your have not posted any. Not doubting your skills but does your pressed BP/lift perform very well? Again not doubting you! )

 

I too have a 3" die that I am using. But only with a 6 ton jack. I dont think that would make to much of a difference. Do you?

 

So when you press, do you use 119 grams of powder? What if not? Or do you just add 10% to any amount that you are pressing?

 

I have probably 200 grams of lift that I am wanting to press tonight ) Also, on a side note do you use the common BP ratio for lifting shells or the lift ratio 74:14:12 (could be wrong on that ratio, dont have my note in front of me now).

 

-Joe

I have a few vids on youtube that you can check out. My youtube name is BonnyPCharlie. Here is one "test" http://ca.youtube.com/watch?v=CZ2DyZz25MQ

 

My lift works well for me...too well sometimes as I've destroyed quite a few shells while testing.

I press all different amounts,depending on how much I make, always using +10% water. Personally I just use the simple 75-15-10.

 

For my 1" cylinder shells I use 5g of -10+20 mesh bp.

[Draco_Americanus]

I use 3 inch delrin for my piston and a clear acrlic sleave with reinforcement camps, the derlin was over 100 bucks for the size chunk i have but it was easy to machine and slides in and out of the sleave like a dream, the derlin seems to take the full force of my 6 ton press with out a problem.

my BP still needs some work though, it lifts fine but it's not as good as goex BP

[acoop101]

I know this is a noob question but what is the point of pressing black powder into pucks?

[TheSidewinder]

In a word, density.

 

Denser powder granules give more "oomph" than ones which are less dense.

 

Pressing it into a puck increases density per square inch (or millimeter, depending on your locale). Somewhere here is a formula for calculating powder density, and lists the "standard" measure for it, expressed in grams per square millimeter (or is it milliliter for volume?).

 

You then run the puck through a corning machine (search these forums for, I think, "corning machine") to create sizes of particles that fit a standard definition (FA, 2FA, 3FA, etc).

 

That's a VERY brief description. Search the forums for more info.

[bmarley5780]

Yes it is called corning when you press the BP.

 

For those who press:

 

-How long do you wait after pressing before corning it?

 

-How hard are your granuales?

~After 24 hours if decided to breakup the puck. The granuales can still be crushed between my fingers? Should these get harder?

 

-Joe