248 replies to this topic

[portfire]

Excellent advice there aquarius,thanx.

I did weight the shell (unpasted mind) to get the weight of the stars,so I'll know what i need for the dummy header.Looks like a 'tube rolling day' tomorrow

In the mean time,i have a tube ready for another 19mm coreburner test.From how the last test went and PGF's advice,this one may work.Plus,if i get the time,i going to build a 50mm bag-mine with the leftover stars,as there's quite a few of them.

dean

[Pretty green flames]

My baby



I poured my heart and soul into this one, it's so fine looking it will be a shame to fire it. Anyway, the rocket is the same as on the previous page. The header is a 2.5" canister with chrissy 6 cut stars and Win #10 comets. Hopefully the result is going to be a silver palm with a chrysanthemum centre (Would probably look better the other way around but hey, i'm experimenting), fingers crossed

@Portfire, I hope your next 19mm one flies

Cheers

[dr thrust]

ho, man! that is to nice to fly! shes beautiful well done you bah dam postal strikes! iam still waiting for my 25mm bar to make a rammer, ho well extreme measures needed going to cut the outside "broom" down a bit, its just right

Edited by chris m, 13 October 2007 - 05:18 PM.

[portfire]

Excellent work there PGF,look forward to the vid I'm pretty dam sure alot of us feel the same way.It's sad to see your "babies" go

Anyway.Here's my forth 19mm CB,just about ready to go.



Spent a little more time on the details.Note the kraft instead of tissue paper at the base.(Thanx for the pic PGF lol) I find it holds the visco in place more firmly.Plus adds a pro touch Love tying clove hitch knots for some reason

Has suggested i'v added 15% C to the fuel.With light on the failed 15mm,i'v also increased end-plug thickness to 15mm(plus nozzle) and instead of using just powdered kitty litter,i'v also added course granules,(5-10 mesh) to "grab" the tube more.This could have been one of the reasons the past 3 failed.

Also,here's a quick look at a 50mm bag-mine i'v made with the leftover chrys#6 stars.




dean

[Pretty green flames]

Yaaay, so friggin happy The rocket worked flawlesly, i couldn't be more happy right now.

For a start another test of the 20mm rocket (110g header (sand))


And now the real thing


So happy

[Jerronimo]

Nice job pretty green flames

That WIN#10 was a disappointment though.
When you read winokurs comments on that formula he says ''Excellent white glitter with long tail, fine grain and dense'' in your video I just see a silver ball, no glitter at all.
Just pressed 1 kg of stars with that composition hoping it would be a realy nice silver glitter...

[Pretty green flames]

Nice job pretty green flames

That WIN#10 was a disappointment though.
When you read winokurs comments on that formula he says ''Excellent white glitter with long tail, fine grain and dense'' in your video I just see a silver ball, no glitter at all.
Just pressed 1 kg of stars with that composition hoping it would be a realy nice silver glitter...

I agree with you there. Every star I make that is supposed to be a White or Golden glitter ends up burning like a silver streamer but they do have a dense silver tail which I like so i don't complain much I might try sourcing the problem though, maybe it's my aluminium (0-140micron Epoxy filler aluminium, no particular grain shape, looks like granular aluminium).

Thanks for the comment

[portfire]

Well..Yet another CATO.This one looks like the previous failure but,with less of a bang.

http://video.google....956312864372610

I was unable to find the rocket so i can't do a "postmortem" but,obviously,the end-plug blew.The fuel must still be to quick so,i'm going to reduce milling time to 15min but keep the 15%C and see how that go's.

P.S Great work there PGF.(he says with jealousy )

dean

[aquarius]

@Dean:
What rocket are you talking about, the 15 mm coreburner og the 19 mm endburner?
Post some more details and it will be easier to help you out.
I haven't had the chance to look at the video yet, but I think you would be better off widening your nozzle than working with green meal.
Just my 2 p's.

[marble]

portfire, try making one with a larger nozzle and after your ram the end plug fill the end with hotglue or epoxy. As ive found out no matter how slow your fuel is if the nozzle is to small its just going to cato.

[portfire]

@Dean:
What rocket are you talking about, the 15 mm coreburner og the 19 mm endburner?
Post some more details and it will be easier to help you out.
I haven't had the chance to look at the video yet, but I think you would be better off widening your nozzle than working with green meal.
Just my 2 p's.

My bad.This one is my 19mm i'v been working on.All the specs on both are in this thread somewhere but,to save time here's the page with the details on the 19mm.I think the dimensions are fine,it's just a case of "playing" with the fuel.

http://www.pyrosocie.......=1661&st=90

I'v had the 15mm working great up until now,due to the fact that i removed the end-plug.I'v also had to roll more tubes for them and will be testing a few this weekend.

P.S Just about to upload the bag-mine vid but i'll post that in the mine thread

dean

Edited by portfire, 16 October 2007 - 01:57 PM.

[aquarius]

So your 15mm worked great without the endplug? That's a new one. But as long as it works!!

I made a 20 mm coreburner as well, but had no time to test it so far. Specs: 20 mm ID, 30 mm OD, 8 mm spindle/nozzle and a spindle length of 100 mm.
I'll try with my slowes fuel first, something tells me if it blows, its gonna make a hell of a bang...

[portfire]

So your 15mm worked great without the endplug? That's a new one. But as long as it works!!

Sorry,my bad...again..All of my 15mil's have had a end-plug,my first w/header didn't,which is why it failed.

Good luck with your rocket BTW

dean

[Jerronimo]

http://www.pyrobin.c...c...0+10+20.avi
http://www.pyrobin.c... inch win10.avi
http://www.pyrobin.c... inch win12.avi
http://www.pyrobin.c.....slow gold.avi
http://www.pyrobin.c.....r flitter.avi
http://www.pyrobin.c.....1 glitter.avi

Here are a couple of video's of the rockets I fired tonight.
These were all plastic shells, to bad I didn't get good breaks and star ignition on all of them.
Probably didn't glue the seam properly and I ran out of filament tape to reinforce the shells, it shows!
The Win10 stars were a disapointment they didn't glitter at all .

All stars are starplate pressed 10mm and primed with meal+5%MgAl.
Burst-charge is 5:1 Bpwillow/ricehulls with 3.5 gram for 3'' and 6 gram for 4'' KClO4/NaBenz. wistle booster.
Weight 3'' shell +/- 150 gram
Weight 4'' shell +/- 300 gram

1 pound rockets pressed on a 12 ton shoppress http://www.pyrobin.c...ress 12 ton.jpg I have a blue one with a bigger cylinder that was a bargain at 100 euro's.
Pressure approximately 8000PSI on the rammer, Greg Boyd standard Bp core tooling all with nozzle.
Nozzle comp. is 75% betonite clay 25% ground kitty litter to let it ''bite'' the casing.
Rocket fuel for the 3'' headers is 65/25/10/2 KNO3/C pine/Sulfur/Vaseline(probably need to use a slower fuel, rockets are going to high) .
Rocket fuel for the 4'' header is very hot 3 hour willow Bp +2% vaseline .

Top notch quality tubes Chris, they can handle a realy hot fuel, no problem lifting 4'' babies

Edited by Jerronimo, 20 October 2007 - 08:11 PM.

[Pretty green flames]

Great rockets man, i love the first (3" BP silver), mind sharing the formula with us? Also the Slow gold was fantastic.

I'm impressed that your rockets don't CATO when you use hot BP in them. Question. Does vaseline significantly slow the fuel down? I want to use it in my core burners for easier ramming.

PGF