Need help with determining nozzel size

[speditty]

I'm making a red rocket using Red Rocket recipe from skylighter.com:

 

Red Magnalium Chuffer Sky Rocket:

 

Strontium Nitrate 55%

Magnalium, -325 mesh powder 28%

PVC powder 10%

Parlon 7%

Vaseline (dissolved in Naphtha) +2%

 

I made a 10g batch pressed into a 3/4" tube of pvc with clay nozzle and plug. I put a little puck of BP tight to nozzle with fuse attached before pressing in the 10g of the rocket mix. Let the solvent dry, then pluged other end and glued it to a knex roller coaster to test if it will make enough thrust to be worth making another to take to the quarry for testing in air. I released the coaster when the BP was burned and it had fully ignited the rocket mix.

 

Do you think this will make enough thrust to get good lift for maybe small shell of stars?

 

Video here:

 

Let me know if you think nozzle is right size or not, or how to determine that.

Thanks

[yvariro]

Hi,

 

nice try but i'm not sure if this rocket motor will lift shell ^^

 

what is the ID of your nozzle ? and what type of rocket motor do you use,coreburner or end burner?

generally,the ID of your nozzle is 1/3 of the ID of your tube

 

here is good arcticle^on rocket http://www.creagan.net/fireworks/rockets/rockets.html

[speditty]

The ID of nozzle was 3/16'' and the I tried doing coreburner like I pressed 7g of the mix in seperate tube then drilled hole through middle of it and then pushed it into the rocket tube and then pressed it again with the last 3g of mix so it didnt have hole all the way through the fuel.

and thanks i'll check that site out!

[Col]

The skylighter article used standard bp coreburner tooling so 1lb tooling might be the way to go. Paper tubes are much safer and stronger than pvc.