8 replies to this topic

[broadsword]

How do you make a report in a rocket? I cant seem to get it to work in either a rocket or a small projectile from a roman candle? It just doesnt go bang/pop it just sounds like a rocket becaus eit is all rushing out off the small hole made to pass the fire! How do you all make your rockets go bang?

[Pretty green flames]

This is the procedure i use using a B6-4 motor.

Roll a tube with the ID of the motor.
Take of the cap separating the BP Charge at the end of the motor.
Fix the motor in the tube with some hot melt glue or elmers.
Pour 15 grams of FP (70:30 ofcourse) in the tube and seal it off with an end cap and a bed of glue.
Let it dry


With a home made motor things are basicly the same only that you drill a passfire
hole that will ignite the FP charge


Any of these 2 should give you a quite strong BANG


also for a roman candle.
Fill the projectile with a couple of grams of FP and there ya have it



Big bangs can also be made with BP but it has to be very good. And the casing needs to be strong so the pressure can bild inside.


Hope i helped
Take care

[broadsword]

And how small should the passfire hole be because i had the problem of the gases etc. escaping through the small hole?
I am using BP as i do not want to go onto FP yet! and i can make maroons with my BP so i assume it would be ok to use it for reports?

Edited by broadsword, 14 December 2004 - 02:15 PM.

[maxman]

Drill a hole 2mm dia just into the propellant grain,at the side of the top plug NOT the center. Then pack the hole with meal powder using the other end of the drill bit. Works every time!

[Pretty green flames]

I am using BP as i do not want to go onto FP yet! and i can make maroons with my BP so i assume it would be ok to use it for reports?

BP Can be used fo good reports.....just make sure that the casing is strong enough
so that the pressure can bild up

[adamw]

Please make sure you perfect your rockets before going on to the bangs!!

[Phoenix]

If you still are having trouble with the gas escaping through a smaller hole, you could try making some cracker fuse and ramming a clay plug around it, Chinese firecracker style. This gives the most complete confinement possible, and the casing will almost inevetably be burst, even by the slowest BP.

BTW, you are leaving the BP for the report loose, aren't you? People will often ram it tightly, and whilst this can work with sufficient confinement, I have found that for me loose meal powder (mill dust) gives better results than packed or grain BP. By "loose" I just mean not packed solidely - it does not need empty space above it, and leaving a space will sometimes complicate plugging the top of the tube.

Filling a passfire hole in a bulkhead with BP is not usually necessary. the pressure in the motor will force a jet of flame and sparks through the hole into the charge above.

For cakes, I either to make a chinese firecracker type thingy, with a fuse in a clay plug, or make a saettine insert. What are saettines? They are small salute inserts fused with black match and sawdust plugs. Here is my method for making small saettines (which I actually ususally put stars and BP in, but they will work as salutes)...

1) Dry roll a thinnish paper case. The method I describe here is intended for a 12-15mm ID saettine, so maybe 12mm by 5cm is a good size to start with. You'll get 4 cases from a sheet of A4.

2) Slip a case over your rammer. Fold in the sides over the rod, and whack it (by hand is fine) on the bench to lightly seal the bottom end.

3) Now tip some fine sawdust into the tube and pack it down with the rammer. Again, by hand is fine. This should create a plug about 10mm thick.

4) Pour in enough fine grain BP to fill the tube to within 1.5cm of the top. Flash will obviously be brighter and louder, but I'm happy with BP, with or without stars.

5) Now cut a 2cm long piece of good black match. Stick it into the BP/stars at one side of the tube, against the wall.

6) Pack a layer of sawdust on top of the contents, so that it seals around the black match. The thickness of this layer will determine the delay. About 10-12mm works for me, in this size.

7) Now fold in the sides of the tube on top of the saw dust plug. I usually just fold in two sides, so that the black match can remain straight, poking out of one of the resulting "points."

8) Now tie a couple of turns of string around the length of the saettine, resting in the V at the top end. Cotton or jute are fine, you needn't use flax hemp spiking twine.

I've used these in mines (great), rocket headers, and cakes. The string at each side means that they don't fit as closely in a mortar tubes as would be nice, so they aren't actually so great to lauch singly from tubes, but if you wrap them in a bit of masking tape to make them "rounder" they're OK.

[broadsword]

Do you have a pic of them at all?

[Phoenix]

Not at the moment. I could draw and scan some sometime. There is an excellent illustrated description of some slightly larger saettines on Passfire, which is how I learned how to make them.

Saettines probably actually need a faster powder than whatever candle inserts you're using at the moment, since the sawdust plugs are not terribly gas tight and the hole where the black match has burnt is fairly large, so I doubt they'd really work any better. I just included the description since that is a type of report insert that I sometimes use.

BTW, when I said I used them in "rocket headers," I meant that I stick a couple in the heading of a larger rocket, along with some stars.