1569 replies to this topic

[Caramanos2000]

Thanks for the tip, gonna need to get some Lampblack and red gum also. Anyway my own recipe Bp star which was pumped and cut. The vid is about a 1/4"x1/4" pellet.
http://s104.photobuc...FirstBpStar.flv

No it doesnt take that long to ignite. it was dark and I couldnt see were it was.

Edited by Caramanos2000, 01 June 2007 - 05:39 AM.

[Bonny]

Thanks for the tip, gonna need to get some Lampblack and red gum also. Anyway my own recipe Bp star which was pumped and cut. The vid is about a 1/4"x1/4" pellet.
http://s104.photobuc...FirstBpStar.flv

No it doesnt take that long to ignite. it was dark and I couldnt see were it was.

Star looked nice. Should look good flying through the air.I think we're in the wrong topic area...I've never used lampblack, just substituted airfloat,formulas work but don't know how much difference the lampblack would make. If you are only looking for smaller amounts (like ounces) you should be able to find redgum on ebay,look for yacca resin.

My question here is how to attach a rising comet on top of a snug fitting cylinder shell that is bottom fired. Is it possible? Maybe sticky match from lift charge to comet? I have added small comets to 1" shells and they work well, but would the same work on a 3" shell?

[Creepin_pyro]

My question here is how to attach a rising comet on top of a snug fitting cylinder shell that is bottom fired. Is it possible? Maybe sticky match from lift charge to comet? I have added small comets to 1" shells and they work well, but would the same work on a 3" shell?

The lift gasses take care of this - no need to match the comet at all (presuming it's primed sufficiently!), whether it's on the top or bottom. Just make sure it's securely attached.

[BrightStar]

My question here is how to attach a rising comet on top of a snug fitting cylinder shell that is bottom fired. Is it possible? Maybe sticky match from lift charge to comet? I have added small comets to 1" shells and they work well, but would the same work on a 3" shell?

Since I would be using a top-fused arrangement for 3" can shells, I would just run the leader from the time fuse to the comet then down the side into the lift... The comet would probably ignite from the lift gas anyway, but since it's next to the time fuse, why not use the leader to make sure?

[Bonny]

The lift gasses take care of this - no need to match the comet at all (presuming it's primed sufficiently!), whether it's on the top or bottom. Just make sure it's securely attached.

I had a comet on top of my first 3" cannister shell (see post 1160 on this topic for video). The comet did not light from lift. I did have a "skirt" on bottom of shell to contain lift though. It was originally a lift cup, but shell with quickmatch running down side was too tight in mortar, so I bottom fired instead. The comet was only about 1-1/2" diameter. Maybe the skirt prevented the lift gasses from reaching comet, which was centered on top of shell. maybe had the comet been near the edge it would have worked?It was a tiger tail with meal prime. Small TT comets on 1" shells even without prime seem to work well for me.

[Caramanos2000]

Lacking the chemicals needed for star comps i came up with these. Hopefully I will get what I need soon.
http://s104.photobuc...t=StarComps.flv

[Caramanos2000]

Tried out my Al and Bp/Mg stars in a rocket. THey worked a treat. Looked like a cross between white and pink. Nice glittery tail.

[Strobe]

Hi,

I'm at a point where I want to try making my 1st shell and I have a few questions. I'll be using a 2 inch plastic cylinder casing for my 1st attempt.

Lift Charge
I have Geox FFg and home made BP available ( Sulphur and Hardward Charcoal ball milled for 30 hours prior to combining with KNO3 using the CIA method). I havent tested the homemade stuff yet so I'm not sure if its appropriate for lift.

Is the Geox FFg ok to use? Its a finer granulation than 2FA, 16 - 30 mesh for FFg versus 4 - 12 mesh for 2FA. I've seen various posts about the recommended ratio of lift powder to shell weight but I'm not sure how to account for the fact that I would be using FFg instead 2FA.

I realize it will take experimentation to fine tune it, but i am just looking for a reasonable starting point to work with.

Burst Charge
I have the FFg and home made available or I could use a KP burst if that is advisable. I'm not real clear on which would be best to try with this size of shell.

[maxman]

I use 15g of 3FA Equiv for 2.5" shells. 2FA I would use 20g. 2Fg is finer and faster so 10g might be about right. KP needs to be well confined to work. I would use BP first to burst and use fibreglass strapping tape to get as good a break as you can then try KP with strapping tape to see what difference there is

[Strobe]

I use 15g of 3FA Equiv for 2.5" shells. 2FA I would use 20g. 2Fg is finer and faster so 10g might be about right. KP needs to be well confined to work. I would use BP first to burst and use fibreglass strapping tape to get as good a break as you can then try KP with strapping tape to see what difference there is

Ok thanks, that seems to be general area I was thinking of. The O.D. of the casing is 1.75 inches which is a little smaller than yours, so I may try a smaller lift charge like 5-8 grams. I'll try it out on a shell loaded with dog food pellets and see how long it stays up.

What kind of altitude should I be looking for in terms of burst height for this size of shell?

[Bonny]

Ok thanks, that seems to be general area I was thinking of. The O.D. of the casing is 1.75 inches which is a little smaller than yours, so I may try a smaller lift charge like 5-8 grams. I'll try it out on a shell loaded with dog food pellets and see how long it stays up.

What kind of altitude should I be looking for in terms of burst height for this size of shell?

There is a reference table for shell heights on passfire. You do have to be a member or trial member at least to access. Tons of info there. The rule of thumb I think is 100ft+100ft for every inch of shell diameter...ie 2" shell should travel 300ft...although many people prefer to burst smaller shells lower so the effect is more visible. My 1" shells typically go about 100-150' using 5g homemade BP lift.

[Wyvern]

Just fired a 3" shell with some test stars in, the bright ones are a velinr blue but were washed out as it was far too bright (damn the longest day) and the glitter on top turned out rubbish but ill tweak the mix at the weekend i was pleased with a little experimental device which i put in there which was a small 5/8" id tube with clay at one end and glitter with dragon eggs pressed into the tube and primed at the end which is the long lasting "star" coming down to earth, once i get the mix right ill be putting them in a 4" canister and hoping for a weeping willow type effect.

Shell weighed 140g
27g BP lift
BP on rice hulls with 2g whistle as a booster burst charge

Edited by Wyvern, 21 June 2007 - 10:45 PM.

[maxman]

Fired two 3" shells. The first was Winokur39 that simply did not glitter! I used strontium carbonate instead of the barium carbonate that the formula called for so maybe that was the problem I dont know. I have made several post about this and was under the impression that it would work. I used 200mesh aluminium, the same as I use for D1 glitter. I dint over do it with the water either. Very dissapointed!

The second shell was 3" Buell Reds with 16 small Blesser white strobes thrown in. The red stars were beautiful, the white strobes were good but very slow, even though they were very small, about 6mm x 3mm one even made it to the ground The break on these shells was poor. Not a patch on my previously best ever Tiger Tail Using BP as the break seems somewhat hit and miss with these. If you look at the break on my Winokur39 and compare to D1 Glitter you can see how the break shoots out at one side. I think this is where the top leader hook blows out of the Gamon shells! This obviously didnt happen with the tigertail or Buell red shells. I did expect a better break from the Buell red as I made two wraps round the middle and two wraps diagonally on each side and over the hook part on the top. Maybe this stoped the shell shattering as it should.

Next time I might try KP as the burst.

Any comments or advice welcome, but I wont be using flash or whisle boosters.

[sasman]

Maxman..I love that RED!!!.. is that how good it looked in real life or does the camera add a bit of colour?..The breaks do look weird They look like they are jetting out of the top half of the shell,as you say that is were the large top plug is located?..Are you glueing 100% making sure the bond is perfect?..I rekon if the bond is perfect it could be down to the fact that your burst charge is not strong enough..The pressure build up is to slow and finding the weak link.. Lets see what happens when you try KP...

I like those white strobes,i am surprised how slow they flash ? blesser mention using 100 mesh Magnalium? Did you use 200 mesh ? which i would have thought would strobe faster..I havent a clue why your glitter did not work...Look forward to seeing more of your shells...

[Wyvern]

Heres the latest shell i have made, just waiting for nice weather to launch it.
It contains my gold tail stars with a ring of blue, burst is bp on rice hulls with a whistle booster.
the smaller shells have some yellow stars ant Ti in them, burst with flash on rice hulls.

i have since primed the end of each bit of visco and they are timed to go off about 1 sec after the main shell.