Big Ass Rocket

[frogy]

Hmm... On the 23 tons of pressure thing...

 

Your saying I'm going to need a ~25\30\50 ton press (not sure what increments they are sold in) and a big-ass A-Frame of H-Frame to hold it.

 

I'm not sure if 3/4" threaded rod with 3/4" Flat bars for support will hold from all that power.

 

Does anyone know how to make your own Air-powered hydraulic ram? I see those big shiny pump attached to the bottom of the piston, similar to where a Pressure gauge is added.

 

Anyways I'm going to have to get on the shopping for Lead thing... I'm calling around now to auto shops asking for tons of lead... I'm hoping to get around 90 pounds for upto (3) 6" Jars...

 

About how much media is needed for (1) 8" jar?

 

I'm also calling Kastner HDPE begging for 6" and 8" Mortar scraps

[cplmac]

22.96 tons is the pressure you will be applying at the standard 6500 PSI loading pressure used for BP rockets. I load my whistle rockets at 3500 PSI which is 12.36 tons. The surface area on a 3" ID motor is a little over 7 square inches which is multiplied by whatever your loading pressure is divided by 2000 will give you the number of tons of pressure you are putting on the press and ram in total. I have a 20 ton air over hydraulic H-Frame press and it starts to deform at about 10 tons, so I only bring my whistle rockets up to 12 tons before relieving the pressure because there is no telling how the press is going to come apart when it does, could just shoot a bolt out or if you're lucky it could just bend.

[oskarchem]

Frogy I calculated the amount of media needed for a 8" jar.

 

Assuming your jar has the folowing specs: 8" tall, and 8" in diamiter it has a volume of 6639cc. A jar has to be half full of media: 3319cc.

 

I calculated the media (Dunno if this is the right size or not):

 

Media diameter: 2"

Media Height: 2"

 

The folowing calculation for the volume of a cylender:

 

V= Pi(2.52)²x5.04

V= 100cc

 

SO roughly if you use the specs wich I gave you will need about 33 pcs of media.

 

If these calculations are wrong please correct them.

[frogy]

Haha. Thanks for the calculations, but those media sizes seem insane.

 

I was planning on making quite a few "Pancake" jars... Which are normally between 5"-6" of 8" HDPE pipe.

 

Going by 6" by 8", you get about 4942 cc

Half that... 2471 cc

 

Lead media... I'll cast about 3/4" diameter balls.

About 3.619 cc each.

 

2471 / 3.619 = 682???

 

The balls would be about 41.039 g/each if 100% lead (definitely not)

 

I always mess up calculations like this, and I'm to tired right now to care... Maybe I'll fix it tomorrow

[oskarchem]

I was thinking that you were going to make cylender media, like on passfire, you know getting a 2" copper tube and pouring in the lead, it seems easer than ball media. And you would need less than 682.

 

Using your specs I caluclated: 552 3/4" media

 

V=Pi(0.75)²

V=4.47cc (and not 3.619cc)

[frogy]

probably some 1" by 1.5" cylinders or so then... Or 1" balls.... No way in hell I could handle making 552 balls.

 

1" by 1.5" Cylinder = 77.2222 cc

 

I believe your math is incorrect for the Spheres.... I have no idea what you are doing with Pi(Diameter)²

 

Volume of a Sphere: (4/3)Pi(Radius)³

(4/3)Pi(0.375)³= 0.22089 in³, or 3.619 cm³

 

Volume of a Cylinder: Pi(Radius)² [area of circular base) * Height

For 2" by 2" cylinder... Pi(1)²*2= 6.283 in³, or 102.96 cm³

 

2471/3.619 = ~ (683) 3/4" Balls

2471/8.58 = ~ (288) 1" Balls

28.958 = ~ (85) 1.5" Balls

2471/12.87 = ~ (192) 1" by 1" Cylinders

2471/19.305 = ~ (128) 1" by 1.5" Cylinders

2471/102.96 = ~ (24) 2" by 2" Cylinders

 

I'm thinking about 62 lbs. of lead.... Which doesn't really make sense for a 1.305 gallon jar. Seeing that 1 gallon jars only use about 30 lbs. of media.

[oskarchem]

Sorry I forgot to use the radius instead of the diameter. I would use the 2"x2" media, but it's all up to you. Because cutting up 128 is quite a job.

 

Good luck.

[frogy]

Has it been proven that smaller media mills better?

 

I just would like to use the most efficient media, though less casting would be nice.

 

2" brass pipe is a lot less than cheap though... I may just make plaster molds...

[oskarchem]

I don't think that smaller media will mill better, it will probably be the same, if you have to fill up the jar half way up, you will still use the same amount of lead.

 

I was talking about copper tubing. 50" long cut up into 10" segments the copper pipes would last you a long time so you could make alot of media with it. Theres less hastle than making plaster/plastic molds wich will only last you a couple of meltings.

[jacob]

Smaller media=less empty space between media=faster, finer milling (I think)

 

You'll need about 30lbs of lead per gallon of mill jar, I would go with 3/4 balls or cylinders, if you haven't already, you should read Lloyd Sponenburghs "ball milling theory and practice for the Amateur Pyrotechnician" a very usefull book, it should tell you everything you need to know.

 

One last thing, large diameter pipe is very hard (if not impossible) to cut straight without the right tool(s) (aka a lathe) I have a bunch of 8'' HDPE gas line but I can't use it for mill jars because I can't cut it straight enough.

[tentacles]

I had my FIL cut my 8" pvc for mill jars on the big lathe where he works. About the only way to do it unless you know someone with a friggin huge chop saw or a bandsaw with good jigs. HDPE would be much more difficult to cut because it's so slick, it will be hard to keep it in a chuck.

 

I wouldn't bother calling car shops, the people who answer the phone often don't have the time or give a damn about you buying some of their wheel weights. Better off showing up in person with a fishing story (literally).

 

Frank, is T planning on making any 3" tooling for cplmac? I know he said they had that nice 3" aluminum bar stock like that piece he gave me with the 1" hole in it. What size core do they use, again?

[hst45]

One last thing, large diameter pipe is very hard (if not impossible) to cut straight without the right tool(s) (aka a lathe) I have a bunch of 8'' HDPE gas line but I can't use it for mill jars because I can't cut it straight enough.

jacob, HDPE tubing will cut fine with common woodworking tools, so a miter saw will work great. If your miter saw is too small to cut 8", just set a stop at the desired length and roll the tube into the saw blade and you'll get a perfect circle every time. It will leave some bits of material on the cut so you'll have to clean up the edge with a file.

[bogey1]

3"ID Ti Whistle To Report, Windows Media Player Compatible

sweet, nice report..

[shadowrun]

I've been collecting shrink wrap tubes form work that might be what you need they measure 3" id about 7/16 wall thickness by 21" long. If these will work I will gladly send them to you. Also if you need lead ingots widners has large ammounts http://www.wideners.com/searchview.cfm When I need lead I go to junkyards the lead wheel weights are all over the groung. I got about 70lb for $15. I melt them down in a pot skim the impuritys off the top and this lead is as good as any. But I also reccomend heat treating to harden the lead.

[shadowrun]

Sorry I didn't realize how old this therad was until after I posted. I was searching the forums for info and got caught up in the coolness. Anyway the offer on 3" tubes still stands I get like 8 of them a day.

[dagabu]

Sorry I didn't realize how old this therad was until after I posted. I was searching the forums for info and got caught up in the coolness. Anyway the offer on 3" tubes still stands I get like 8 of them a day.

 

It's all good, old posts need a kick sometimes to get them going again.

 

D

[TheSidewinder]

Besides, the rocket video off the first page is still cool as hell.

[scarbelly]

Those were AWESOME rockets. Edited October 14, 2009 by scarbelly

[dagabu]

What ever happened to Cplmac?

[Gunzway]

What ever happened to Cplmac?

 

I believe he's still around. I sent him a message a year ago or something and he pretty much said he's been busy with his life right now and doesn't have as much time to spend on pyro. I naturally assume this has been the case since. He made some things around 6 months ago and uploaded a couple of videos onto Youtube.

[pyrochris732]

I sent up another one tonight at the HPA get together. This one was a little bit lighter and flew a bit higher. I headed it with 5 2.5" salutes and 2 3" salutes. I'll see if I can get the video up tomorrow. Interestingly enough, I live twenty minutes from O'hare, and work on the north border of the airport.

 

 

this is oddly off topic but i was reading about american flight 191 the other day.. did you happen to be near it when it happened in 1979? Not sure how old you are

[dagabu]

Wasnt that the one the rolled at Ohare? Whats that got to do with a big ass rocket?

[Guest no6]

cplmac,

 

Your rockets are amazing. Thanks for the videos!

[madmandotcom]

it is rather a wide engine, the biggest one i have seen till now was only 3/4 inch

[dagabu]

Here is another one of CPLMAC's that was posted on YouTube.