9/21/07 Launch

[ddanhra69]

The wind has really been strong here in Jax.,FL. It's been showing signs of slowing now. I hope that tomorrow evening we can launch a few.

[barone]

Such an arsenal....be sure to post some pictures......you know how we love to see them... :D

[ddanhra69]

If weather permits I think the only one's i'll launch is Astrocam, Oracle, Big Bertha and Mustang.

[ddanhra69]

I'm going to try something a little different on the Mustang load, E16W 29 MM. Instead of taping the front of the propellant grain, so the ignitor won't go past it. I measured it so I can precisely place it at the front of the grain. :eek:

[barone]

I'm going to try something a little different on the Mustang load, E16W 29 MM. Instead of taping the front of the propellant grain, so the ignitor won't go past it. I measured it so I can precisely place it at the front of the grain. :eek:
Well.....that means your delay charge will start later. Normally, the igniter is at the base of the delay grain and is burning the same time the propellant is.

[cas2047]

Great fleet! Of course the Sat V is awsome and my favorite in your fleet and in mine, but that Strong Arm is coming up a close second. That is one cool looking rocket. I bet it really gets up there too.

I think I need to buy me one of those! :D

[ddanhra69]

Well.....that means your delay charge will start later. Normally, the igniter is at the base of the delay grain and is burning the same time the propellant is.
Well, if i've been following the directions correctly, they say to put a piece of tape at the end of the propellant grain on E and F reload only, so the ignitor will stop at the forward portion of the propellant grain. I don't know? However, I didn't get to launch this afternoon. The wind stayed kicked up.

[barone]

Maybe I'm just misunderstanding what you're saying. I understand you to say that the igniter will be towards the aft end of the motor :confused:

[ddanhra69]

Maybe I'm just misunderstanding what you're saying. I understand you to say that the igniter will be towards the aft end of the motor :confused:
Yes, like on a 29 MM E16-7W, the propellant grain is only like 1.5" long. There's a lot of space between the forward end of propellant and the aft end of the delay grain. Directions say not to let the ignitor go past the forward end of the propellant...???? I don't know?? It lights though. Wound up launching today, (9/22). The Oracle misfired at first, but with a new ignitor it left the pad. Instead of a D12-5, I put a E24-10W in it. It went out of sight until the 'chute came out. The others did well too. I have video and pics coming to you.

[tbzep]

Yes, like on a 29 MM E16-7W, the propellant grain is only like 1.5" long. There's a lot of space between the forward end of propellant and the aft end of the delay grain. Directions say not to let the ignitor go past the forward end of the propellant...???? I don't know?? It lights though. Wound up launching today, (9/22). The Oracle misfired at first, but with a new ignitor it left the pad. Instead of a D12-5, I put a E24-10W in it. It went out of sight until the 'chute came out. The others did well too. I have video and pics coming to you.

The tape at the end of the grain preventing the igniter from moving past the grain is just to make ignition more reliable. The igniter is more reliable if it is actually touching the propellant grain. When the motor ignites, the delay train ignites also and burns simultaneously, so there's no advantage to shoving the ignitor farther. The delay train burns at the same time as the propellant grain. The only difference in eliminating the tape and allowing the igniter to go farther up is less reliability of ignition. With aftermarket igniters, it's not that big of a deal for the igniter to touch the pyrogen, but weaker igniters like the Copperheads and others with minimal pyrogen need to touch the propellant for 100% reliability.

[ddanhra69]

http://i212.photobucket.com/albums/cc40/dwiaver/HPIM0090.jpghttp://i212.photobucket.com/albums/cc40/dwiaver/HPIM0091.jpghttp://i212.photobucket.com/albums/cc40/dwiaver/HPIM0092.jpghttp://i212.photobucket.com/albums/cc40/dwiaver/HPIM0095.jpghttp://i212.photobucket.com/albums/cc40/dwiaver/th_L6Oracle.jpg (http://s212.photobucket.com/albums/cc40/dwiaver/?action=view&current=L6Oracle.flv)

[barone]

Great video! Guess the 30 seconds wasn't enough time on the E motor. On Ds, I've got pictures of me walking up to retrieve the rocket on the ground....

[ddanhra69]

Great video! Guess the 30 seconds wasn't enough time on the E motor. On Ds, I've got pictures of me walking up to retrieve the rocket on the ground....
Yeah, me too. I'm really not too sure about doing that again since I lost sight of it. If it wasn't so quiet for me to hear the 'chute deployment and then try to regain sight of it with the 'chute out, I wouldn't have found it. It landed softly about 200 yrds away. It went so high that the 30 seconds was way too little time. I need to try to get better with photos though, maybe a foot or so off the pad.

[pantherjon]

Nice launch pictures! Wish I had a field that big to launch from :D North or south of JAX?

My quest to find a field is on going..Still have to find the property caretaker/owner of one good sized field just outside of town..Could always bug the caretaker at our county airport and see if I could use the open area(HUGE) north of the runway..not like we have 30 planes/day landing/taking off there...lol..The airport would be great as it is about 1 minute drive..other field is like a 15 minute drive..