248 replies to this topic

[Wyvern]

Just finished another 1 lb BP rocket with a 3" plastic ball header pasted with 5 layers 60lb kraft with Veline blue stars in a crossed double ring formation with Al Streamer stars between the blue ones, here is a pre launch shot but im going to wait for the rain to stop before launching it. Shell is broken by 1.5g MgAl Flashbag and BP on rice crispies around the stars.

Edited by Wyvern, 04 March 2007 - 12:07 PM.

[portfire]

Now thats one professional looking rocket,nice work .Will you be videoing the launch?(hope so )

[Wyvern]

Now thats one professional looking rocket,nice work .Will you be videoing the launch?(hope so )

Well tonights launch was put off by high winds, i will be videoing the launch and thanks

[Wyvern]

Well i did the launch tonight but the plug blew out of the top which was a real shame for such a nice break

http://tompearceltd..../Movie_0001.wmv

[BrightStar]

Well i did the launch tonight but the plug blew out of the top which was a real shame for such a nice break

Well, it at least you got to see it close up... It was still a really nice rocket - must have taken some time to put together...

Can I ask what method are you using for passing fire to the burst? Which fuel mix / delay comp have you finally settled on?

Edited by BrightStar, 07 March 2007 - 04:18 AM.

[Wyvern]

Well, it at least you got to see it close up... It was still a really nice rocket - must have taken some time to put together...

Can I ask what method are you using for passing fire to the burst? Which fuel mix / delay comp have you finally settled on?

Hehe, it wasnt as close as it looked the zoom was almost maxxed out but yeah it took a good 5-6 hours to make but it was spread over a few days. As for the comps used, the fuel mix is 60KNO3:30C:10S with 5% FeTi added after the core to stop it scratching then as the delay i simply use the rocket mix with 10% Sodium Bicarbonate and a 3 second timed piece of Visco going into the header which uses a flashbag with 50KClO3:30MgAl:20Sb2S3 and Bp rice crispies packed around the stars.

Edited by Wyvern, 07 March 2007 - 07:22 AM.

[portfire]

Hi all
Having not done any pyro for a couple of weeks and wanting to improve my endburner results from the first launch, iv made another one.
Here are the specs

case-80mm,12mmID,3mm wall

nozzle-10mm long,4mm choke.

The propellant is 3hr milled greenmix rammed hard and is 50mm long.I did take pics of this one and will be videoing the launch.


http://www.box.net/shared/frgcqbkuf2



regards
dean

Edited by portfire, 22 March 2007 - 06:32 PM.

[aquarius]

Tried a endburner with almost the same specs, only 15 mm ID.
I used 70:20:10 6hrs ballmilled, wetted and granulated BP, standard BBQ charcoal. The charcoal is not that bad, by the way, not for drivers.
One of them lifted VERY slow, and got stuck in a tree. A driver with a bit more fuel never got off the pole.

If you are going the "end burner way", use your fastest BP, and a smaller nozzle than you might expect.
Please do report how your experiments turn out, endburners are quite cool.

[pyromaniac303]

Tried a endburner with almost the same specs, only 15 mm ID.
I used 70:20:10 6hrs ballmilled, wetted and granulated BP, standard BBQ charcoal. The charcoal is not that bad, by the way, not for drivers.
One of them lifted VERY slow, and got stuck in a tree. A driver with a bit more fuel never got off the pole.

If you are going the "end burner way", use your fastest BP, and a smaller nozzle than you might expect.
Please do report how your experiments turn out, endburners are quite cool.

You say that charcoal isn't bad but they didnt work properly, but when I use my 75:15:10 willow BP I never have a problem.
5/8" seems to a be a size more suited to end burners than 1/2" ones. Smaller ones never seem all that impressive. Use a nozzle about 1/4 of your tube ID, I find that works for me anyway, never had any CATOs with that size. If they still are slow taking off and you have plenty of fuel left try a core/end burner hybrid by carefully drilling a small core and keep trying slightly longer cores til your happy with it, it will just give it a burst of acceleration for the first second or 2 of flight.

Also be very careful with additives like aluminium you can really slow down the fuel only with a small percentage added. 5% or more added to willow BP end burners noticeably decreases performance.

[Pyromaster2003]

Pyromaniac303, you would be better off using 75/15/10 if your using bbq charcoal or possibly 80/13/7. When i make end burners i use meal 50% and green mix 50% then add about 3-5% 250 mesh Al (spherical) and they always perform very well. Also with end burners i use a choke of around 1/5th of the ID of the tube and use 3/4 inch ID tubes.

[portfire]

Hi all
Well iv just tested my endburner and as you can see it didn't go quite as i'd have hoped

http://video.google....210976246600103


Obviously the fuel was not fast enough.I used 75/15/10 milled for 3hr.

aquarius its funny you said that as the same thing happened tonight, and the first endburner i tried never really left the tube .I dont really want to go the "endburner way" as i love the tail on coreburners.The first coreburner i tried did fly quite well,it just went horizontal after 40ft,so i think im going to do most of my rocket experiments with them.


regards
dean

[pyromaniac303]

Pyromaniac303, you would be better off using 75/15/10 if your using bbq charcoal or possibly 80/13/7. When i make end burners i use meal 50% and green mix 50% then add about 3-5% 250 mesh Al (spherical) and they always perform very well. Also with end burners i use a choke of around 1/5th of the ID of the tube and use 3/4 inch ID tubes.

Sorry I didnt mean mine were going wrong, I re-read my post and found how confusing it looked! It was a suggestion to aquarious to use faster charcoal. The only uses I have found for the cheap lumpwood charcoal is for core burners and fountain comps.

Also IMO not such a good idea to make 1/4" or below end burners, they are dangerously unstable, no matter how much adjusting and experimenting I do. One slight breeze and they have a tendency to go sideways, a longer stick and they are too underpowered. With 1/4" core burners they have a little extra power for a bigger stick and maybe a tiny (couple of stars/microstars or 1" shell) payload. Anyone got a solution to this?

[cplmac]

This is my first run at a 4lb rocket. It goes to red strobe to white to report. The only disappointments in this rocket were the delay comps, that mostly sucked, and the direction the rocket took.

4lb to red strobe to white to report

[Pyromaster2003]

That was meant for aquarius sorry about the confusion lol.

I'v made decent end burning rocket with 1/4 inch ID tubes just using 6 hour milled balsa meal, they could easy carry a payload on top il post a video when weather gets better

That 4lb rocket was pretty good cplmac how much flash was the salute on that thing it was a beast!

[cplmac]

It was about 10-12 grams. I just topped off the space above my delay. I do have a couple of serious salute test videos though.