47 replies to this topic

[Painter]

Here's my first 1 pounder with a payload, other than some flash in the last 1/2 of the top.

Enjoy

http://www.zippyvide...r_with_3_shell/

Although it CATO'd shortly after launch, the rocket had enough thrust to send
the 3" shell that weighed 121g up to 100' feet or so!

Going to tame this RP yet!

May drop back to a 2" header next time.

[sizzle]

Apart from the CATO that was very impressive, I like the burst, it seemed quite big for a 3" or was your camera zoomed in?

[Painter]

Nope, wasn't zoomed, just got a real good break!
It was a plastic shell, taped with fiberglass strapping tape
and had BP coated corn cob with a little bit of whistle mix
in the center.

[Frozentech]

Here's my first 1 pounder with a payload, other than some flash in the last 1/2 of the top.

Enjoy

http://www.zippyvide...r_with_3_shell/

Although it CATO'd shortly after launch, the rocket had enough thrust to send
the 3" shell that weighed 121g up to 100' feet or so!

Going to tame this RP yet!

May drop back to a 2" header next time.

I like that one Mike. Still amazing on a frame by frame how that shell blew exactly straight up from the CATO, like an airborne mortar . Did you figure out which half was the Chrys and which the TT stars ?

On another note, weather looks perfect today, so probably launching tonight.

Edited by Frozentech, 13 February 2006 - 07:30 PM.

[karlfoxman]

I can tell you the tigertail are on the right hand side, like the effect but you get from the half and half. I use Degn 1lb - 2lb rocket bp milled for 85 mins and my rockets are on the border line between C.A.T.O and flying. Not tried payload yet but will try some dummy 3 and 4 inch shells.

[Skarphedin]

I continue this thread with my first "shell" payload. The rocket was a
4oz BP rocket with 60:30:10 propellant. All ballmilled separately and screened trough 24 mesh 3 times. I Use tooling from Wolter and homemade kraft tubes.

Movies and pictures: http://pyld.killozap.../pyro/26.03.06/

The payload was a tiny canister shell. about 35mm in diameter and 35mm high. It contained 24
pumped 3/8" chrysanthemum 6 stars with additional charchoal/meal p. (I overwetted the dough and added additional charchoal and meal powder to get the dough drier). The stars was
stacked towards the wall of the shell in 3 rings. 4 gr FFF commercial BP was used as burst.
between the stars and the wall I added some crushed stars (a batch of very poor charchoal stars). I used 3 2-3 cm pieces of BM as a fuse for the shell and a bit of BP slurry.
I used Flax twine to spike the shell. 14 verticals and 4 horizontal. The canister was made of 4 turns of 100gr kraft. The shell weighed 38.5 grammes.

As you can see the break was far from symmetrical, but still better than my earlier payloads. I'm very eager to try again! Do you have any suggestions for how to improve the shell?
Without a sturdy timefuse/spolette, how do you start spiking? I fastened the twine with itself in the first revolution (passed the twine over itself tightly).

[pyromaniac303]

I just made my first payload rocket after testing 2 of the same motor design earlier, the specs are as follows:
* 1/2" ID 4" long and 4mm wall thickness
* 5 silver glitter stars (meal + 10% al atomized)
* 2g BP burst charge, whole header weighed 7.4g
* BP propellant with a core drilled 2" in (as long as my drill bit will go, I'm after some 1/2" rocket tooling if anyone has any good advice)

I will post vid and pics as soon as I can. They will be in .3gp format (use realplayer or similar) from my phone though, because my vid camera codec is corrupted and I can't play back my old videos from it.

[seymour]

Adding Aluminium to meal is not going to make glitter. I know it is easy to get the Aluminium star effects mixed up, but the effects, Glitter, flitter, and plain Al streamer, are, although subtly in some cases, differnt. Not meaning to offend anyone in this post, but this has been posted several times before in these forums. Reading through all the archives can be a bit of a task eh, though a rewarding one.
Good luck with the rocket.

[pyromaniac303]

Ok, your right about that seymour, they were more sort of aluminium streamer stars.

I launched just 20 minutes ago, the header performed as expected, but the rocket violently CATO'ed and sent the stars up much like a mine. I can't really come up with a reason why it did this as my other 2 rockets of exactly the same dimensions, same batch of BP, even cut from the same length of tube, worked well. I think that I need some rocket tooling to be sure the core is 100% identical, which should help to eliminate of few of the unpredictable effects that my rockets have produced.

I will upload videos soon.

[pyromaniac303]

Ok, after ages of searching I managed to find a video converter as my server wouldnt take a .3gp file. It is 2.5 Mb for a 12 seconds video though. I was upwind of it on purpose too, and used a 4 inch slow visco fuse to give me loads of time to run.

rocket_test

No remains were found, after 15 mins of searching I gave up, even though it didn't appear to even take off.

EDIT: To play you MUST save the file to your pc (right click then go to save as), clicking the link comes up with a geocities error (I really dislike these free webspaces, but better than nothing)

Edited by pyromaniac303, 12 May 2006 - 09:08 PM.

[pyromaniac303]

I suspect the reason it CATO'ed must be due to the powder consolidation as I am fairly sure that the core depth and tube length were the same + or - 2mm as the 2 test rockets with no header.

I have since tested a rocket with a wider nozzle and core, and found that it was under powered. I will possibly test ones with the same nozzle width as the one that CATOed, and vary the core length by starting with end burners, on a weighing scales to check how much thrust they produce.

Anyone got any advice on what sort of thrust I should be expecting from a BP rocket of these dimensions?

[Karl]

After my and Pyromainiac303's meetup last weekend, I have just tried out some of his rocket comp & Stars that he had left me to try out. Im sure he will fill you in on the details later.

The rocket used a 18mm OD Tube, with a 13mm ID. The nozzle & core were both 3mm in Dia. The payload I used was a 24mm OD Tube, 2" long filled with Chrys #8 stars and a few pieces of Flying Fish & Falling Leaf fuse.

This was an awesome rocket put it one way. The rocket lifted to a good 50ft before a short delay folowed by a sharp bang where the payload activated and out came the stars. The Stars burn a little too quick but the fuse wizzed around like bees!!

Well done PM303!

[pyromaniac303]

Thanks, the stars were the following formula:

Potassium Nitrate 64
Charcoal Airfloat 25
Sulfur 6
Glucose 5

Originally the formula uses dextrin but I really need to get round to making some, and it is basically chrysanthemum#8 with +15% KNO3 and -15% charcoal to speed up the burn time. This was to ensure that the stars wouldn't blow blind, were easier to light than normal chrys#8 and, as some of them were for my own use, they wouldnt travel too far towards me if there was a CATO.

Hopefully I will tell you my results from them soon, they are still sat in the shed, and because of the glucose they seem a bit crumbly. Also the green flying fish fuse I bought from a recently opened site seems good, I tested it in a small (1") mine last week, and a 3/8"s header rocket (yes it actually flew this time!).

[pyromaniac303]

OK, got a working version of my half inch rocket, now using a set of tools from pyrotooling.com, and 70-20-10 BP as the fuel. Tube length was 5 inches, payload size was 1 3/4" ball shell (one I won at the meetup in Leeds )

BP Rocket

The payload weight was only around 15g as I didn't want to risk using a large payload on my first attempt. The break was 4g balsa bp and a few pieces of green flying fish instead of stars. Got a few 1" hemis I am buying from america to arrive soon, and a few 1 3/4" ones too as I am going to be taking a few of these to Wales when I go in August. (4 mile long beach that I've never even seen more than 20 people on in the day, and never anyone past 9pm, which is when I go down to test some pyro)

Does anyone know the maximum size ball shell I should be lifting with a 1/2" rocket? I was thinking that a 3" was a bit big, and not sure whether this is determined purely by the weight of the shell or by the drag it causes as well.

[pendulum]

That's my first payload rocket, it has just over 1g of standard 70/30 flash as a header. I'll be testing it tonight and I hope it works. I know that the placement of the header isn't exactly the best aerodynamically... fingers crossed.

Edit: well it worked (kinda). It took off well but then it lost thrust. I think because the cored part had all burned up and just the packed solid blackpowder was left to burn at the top of the tube. That burnt for ages so it carried on burning as the rocket fell. After I think was at least 10 seconds after the rocket must have hit the ground, and after I was about to give up and walk away, I heard the bang!

Got a bit of work to do regarding timing.

BTW - I make core burning rockets, which don't require good BP at all (all my blow-ups on takeoff were due to too strong BP), but once you have rammed the BP up to the height of the spindle, does anyone start ramming higher quality blackpowder in? 'Cos I am thinking you need better quality blackpowder to create lift still if you no longer have a core, and then it would be more of an end burner with the good quality BP although obviously you still have a nozzle...

Edited by pendulum, 15 October 2006 - 05:47 PM.