6 replies to this topic

[Painter]

This was a 1 pounder with a 2.5 inch round shell.
Filled with Green Veline's formula stars.
It had BP coated corn husks for burst with .5g flash in the center.
The passfire was 1/8" green visco into the shell with a straw filled
with 80 mesh BP leading to the center.
It acted like an morter once launched! Shot the shell up to about 150 feet!
RP for the propelent, slow BP delay on top, but no bulkhead, then 10 mesh
BP to light the shell fuse, that had slurry primed visco, 1" length outside.
This is the second one that has launched itself, after fireing!
Thoughts?

[fishy1]

This was a 1 pounder with a 2.5 inch round shell.
Filled with Green Veline's formula stars.
It had BP coated corn husks for burst with .5g flash in the center.
The passfire was 1/8" green visco into the shell with a straw filled
with 80 mesh BP leading to the center.
It acted like an morter once launched! Shot the shell up to about 150 feet!
RP for the propelent, slow BP delay on top, but no bulkhead, then 10 mesh
BP to light the shell fuse, that had slurry primed visco, 1" length outside.
This is the second one that has launched itself, after fireing!
Thoughts?

that's a pretty nippy rocket,

[karlfoxman]

I would think its because you did not add a bulkhead, i should think the powder just gave way under the intense pressure when the core was burning. I have not seen your video but i do hope you was a fair way from the rocket when you launched it, an unguided shell/header could go anywhere and when it explodes it could cause damage. Why did you use a visco passfire, this will act as more of a delay than passfire, the term passfire is usually a tube that transfers fire very quickly into the center of the shell. Add a bulkhead and your problems will be solved if your propellant is not too 'hot' and your core is not too large.

[Painter]

Actually, I recovered the tube this morning, and it appears to have blown out about 2/3 rds of the way up.
Just about where the top of the core would have been (using Greg Boyds tooling).
I'll post a pic of it tonight after I get off work.
Not sure a bulkhead would have mattered. Looks more like a possible tube failure!

[Frozentech]

Actually, I recovered the tube this morning, and it appears to have blown out about 2/3 rds of the way up.
Just about where the top of the core would have been (using Greg Boyds tooling).
I'll post a pic of it tonight after I get off work.
Not sure a bulkhead would have mattered. Looks more like a possible tube failure!

Hey buddy... I still think the bulkhead might be the problem, perhaps when the burn came up to the top layer of the comp above the core, the burning suface area suddenly dramatically increased to the point of blowing. I've seen pics of that happening when the nozzle blows out, it taking the bottom inch of the tube with it ? You've got the same tubes I have, I hate to think there is any problem with those !

I should be back in town tonight late, I'll try to catch you on icq.

[Jerronimo]

It's also possible that your fuel is to hot for the dimentions of your nozzle width and core length.
In this case you should add some charcoal to slow down the mix.
Or u didn't ram/press the propellant hard enough, rockets are tricky to get right.

Edited by Jerronimo, 03 March 2006 - 07:38 PM.

[Painter]

This is the remains of the rocket I launched last night!

Photo

Gruesom! LOL