My first rocket :D

[bum]

So I took to the sky today. I'm not sure how long the tube was, but it had a 1/2" diameter-- it was probably 5 or 6 inches. I have a basic understanding of the way black powder rockets work, and I didn't bother spending an hour laying out a plan and just went at it once I got my powder.

 

I rammed a clay plug, then rammed small increments of 3F BP until I neared the top, then I rammed more clay.

 

I know this was a little stupid, but I did some reading and saw that it was OK if you're safe about it-- I drilled a hole through the bottom (not even sure of the bit size-- 3/32 maybe?) with an electric drill very slowly in short intervals.

 

I stabilized with two bamboo sticks taped together and did the balance trick. When I lit it, it first popped (what do you think happened?) and then took off and reached about two or three stories high (three house levels) and then began falling-- but still thrusting.

 

It was wonderful to see my first rocket fly. I'm excited to make my next one.

 

What do you think happened? My guess is that the rocket was too heavy.. I read something about a 1:3 ratio.. ID to length. Mine obviously did not follow that.

 

So my question is, how do I make the hole after packing the rocket? I understand there is rocket tooling that lets you pack it with a hole already in place but it's much too expensive.. so how can I do it without a drill after packing?

[hst45]

bum, I'm not a rocket expert by any stretch of the imagination, but two thoughts occur to me.

 

1) Perhaps the nozzle burned-out. If the clay plug you rammed was eroded by the hot exhaust gasses, the velocity of the escaping gasses would be reduced resulting in lower thrust.

 

2) Perhaps the core you drilled wasn't deep enough. As the grain (the pressed BP) burned, it initially develloped sufficient pressure to lift the rocket since the core exposed more of the aforementioned "grain" was available to burn. As the grain burned past this core the surface area available to burn and generate thrust may have been reduced, in effect making your core-burner an end-burner.

 

If you were able to recover the rocket you should look at the nozzle and see is it was significantly erroded. Is so try ramming it harder, making the nozzle longer, or adding "grog" to the clay. That's my best guess of the problem.

 

Be careful when drilling the core. Always wear gloves, long sleeves, and eye protection. Never, repeat NEVER, assume that it couldn't happen to you. Check out the safety section if you want to see what "it" means. The materials we work with can and will bite you if you become complacent. Anyway, congratulations on your first successful launch. Have fun, stay safe.

[deadman]

I believe the ratio is 1:10; ID:length for most BP rockets.

 

There is always home made tooling, but since you asked about drilling my best advice would to use a manual powdered drill instead of an electric. And definitley not an air compressor. Those are a bit too violent and often weaken the structure of the nozzle and/or grain. It only takes a minute to twist out a nozzle if need be. Also I would suggest end-burners without proper tooling. So you are going to need a hot propellant and a safe one to drill into. As mentioned in a fountain thread make a layer of straight meal as not to worry about hitting metals while drilling through the plug into the compo.

[FUZE]

Congratulations, A pyros first aerial device is a very memorable expierence. My thinking is that while you were drilling perhaps you loosened some of the Black Powder that your rammed and thus creating a air pocket, I have had this happen to me on more than one occasion, My advice is to use a wooden down base for the nozzle. To do this drill a 1/8" hole 1/4" into a piece of wood and get some wood glue fill the 1/8" hole you drilled and stick a 1/8"D X 2"H dowel into it and let it dry. This is a rather crude mandrel however if you pm me I will try to get you a step by step guide on it. Just remember to efficently ram the clay plug/nozzle and then the starter Black Powder the ram you use drill a 2" hole into the center then once you can no longer see the mandrel while ramming it, Use a solid dowel. I did this for about 73 of my first Black Powder rockets

[Pyrohawk]

Hey, Congrats on your first rocket!

 

We need a bit more info, mainly on what the rocket looked like after you fired it. Was the nozzle missing? From the sounds of it that would be my first guess... Sounds like your nozzle blew out (the popping noise).

 

Also, are you saying you used BP from a gun store? Why don't you make your own BP? The grains may not press as well and you could end up with air pockets if they don't all get crushed well. Plus with BP like that you probably wouldn't need a core at all..... that could have caused your nozzle to blow out.

 

Edit: Also I would go with more like 4 inches long for a 1/2" rocket.

[deadman]

Yes, but they are easy to break. I personally believe lady kate's method is almost as cheap and just as good. Except I would make a hole in the brass rod near the bottom to pull it out instead of pliers.

[moonshot]

When I first started making rockets I was using commercial 3f BP. I would spray the BP with some aerosol shellac as a binder then ram it on some homemade tooling to make the core. I found that the commercial BP was way too fast and my first small motors, 2" longx3/8" ID always exploded on ignition. After researching BP rockets on the web I figured out that by adding some homemade charcoal to the 3f BP I could slow the propellant down enough to get a good flight. So I would add say 20% charcoal to the 3f spray it with shellac and ram it. I got the motors to fly but they weren't very consistent. It wasn't until I started milling my own rocket propellant that I finally was able to ram consistently dependable motors. I now build a standard motor using hand rolled tubes 4"long x 1/2" ID. If you can only get commercial powder you might try slowing it down by adding some linseed oil to it. This will also act as a binder. To answer your last question there is no other way to make a core in your motor than by drilling unless you can build or buy some rocket tooling. Keep working on your rockets! It took me 2 years to finally get to where I was making my own powder, tubes, tooling, sticks and headers to build consistent skyrockets. I have posted this pic before but here are some finished rockets using my 4" long 1/2" ID motors.

http://i107.photobucket.com/albums/m314/di.../Picture057.jpg