Nozzle less rockets based on BP

[Sulphurstan]

Does anyone has experience with nozzle less rockets, on BP basis? I just tried out a BP + lampblack mix binded with nc lacquer, small basic core, and it just took off wuuusshhh, like a go getter. Before I continue investigating in adjusting the mix, the ID and the length of future test rockets, I was wondering if anyone already made these tests, and if yes, if they were conclusive or not.

Note: I make these tests to avoid the bentonite nozzling and ramming task.

And yes, i know the thrust will be a lot lower, but stil, ... it lifts up pretty good...

[Sulphurstan]

Forgotten to add in my previous post: If there is already a topic related to this that I didn't noticed, please just tell me so, dont need to start a new topic, if the subject is already discussed somewhere else.

[DavidF]

Most of my rockets are nozzleless, made on black powder tooling. Most folks use milled black powder as their propellant base for this. The charcoal selection and particle size is important. I've only known lampblack to be used for nozzled rockets. Screen-mixed black powder can be used for nozzleless rockets IF the charcoal is well-milled first, and so is the potassium nitrate. A well made 19 mm nozzleless rocket made on BP tooling can lift a 10cm ball shell. This link might help:

 

http://www.wichitabuggywhip.com/fireworks/rockets/nozzleless.html

 

or this:

 

http://www.skylighter.com/fireworks/how-to-make/nozzleless-speed-rockets.asp

[NeighborJ]

I've done tests similar to these, the NC laqeur is a tricky animal to use in a go-getter style motor. Under low case pressure it would make a motor capable of lifting itself,but when I dialed it up so it could lift a payload it was plagued with catos. This is typical of most all go-getter, or poured motors. The NC only made it more sensitive at higher pressure. I abandoned the idea after much testing in favor of the traditional pressed and rammed BP motors. The compaction process pushes the comp into the tube walls and ensures better adhesion than a poured or hand pressed motors.

[Sulphurstan]

@DavidF. Thank you for the interesting links, especially the wichitabuggy!

@Neighbourj. Yes the ramming will for sure make the composition stick to the inner walls... I ll see if I can find a "midway" between poured and lightly pressed/rammed...

Regarding the sensitivity of my NC, it should be pretty low, still I use pingpong ball, which contains only 70pc NC and the quite unreactive camphor. Do you think that this low quality NC could be of a help for staying stable at higher pressures? In regard to pure NC?

[NeighborJ]

Stan you may have better luck than me if you are using the ppballs. The thought never occurred to me. I was working toward hand pressing and then sticking it in the press with a very long dwell time. I was hoping the process would save time but it turned out to be quicker the old fashioned way. I had the best results from Phenolic resin instead of NC because it only has fuel value. I even used it on whistle with success.

[Sulphurstan]

Neighbour, thanx for the reply. Meanwhile, I ve been through the forum, beginning to read your older posts about this nozzleless issue: impressive amount of GOOD ideas and information . I'll go through these old post before experimenting any further.

[yvariro]

Sulphurstan,

 

I've made 3/4" nozzleless rockets using hot bp(willow charcoal) and a bit of mineral oil on a standard tooling. Hard ramming with 1 gr grain. I've never experienced waxed tube though. For the ignition, i never ignited these at the top of the core , i was too scared of CATO

 

Y-M

[Col]

If you dont top fuse one you`ll never find out

[OldMarine]

Some of my best rockets never left the rack! KABOOM!!

[NeighborJ]

What do the bad ones do?

[OldMarine]

Fizzle and fall over. Haven't really had a problem since I got the test stand but I still get to enjoy a bomb on a stick occasionally!

[Sparx88]

All nzless rockets I make after a lot of trial and error use the hottest bp I have, are hand rammed and lit at the bottom. Anything bigger than a 1 lb gets pressed. Still lit at the bottom. Cato's are no fun when you make these things and everything you use to make them.

[NeighborJ]

Aw, where's your sense of adventure? Catos can be spectacular. Let's you know what it is your really dealing with.

Edited December 6, 2016 by NeighborJ

[OldMarine]

I had a 3# nozzleless with a 4" heading full of Ofca's White blow the bulkhead about 5 feet off the rack and it was EXCITING to say the least!

[Sparx88]

Aw, where's your sense of adventure? Catos can be spectacular. Let's you know what it is your really dealing with.

 

Ok I admit, it is hair raising, embarrassing and thrilling and I can usually pull out a good laugh and big'ol YeeHawww

[Col]

An unexpected cato adds spice, especially if it takes all the rockets in the rack with it

[NeighborJ]

I would think and entire rack catoing would be a sour spice but yes exciting.