L3 Build Log - Wildman Interceptor A.A.D. 98

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My TAP insisted on a minimum of 1.5 calibers of stability. Keep in mind that when the rocket goes through mach that the CP will move forward about 1 caliber. I wound up adding 53 oz. to the nose of my stock Punisher 4. The stretched version that I eventually certified with had 24 oz in the nose.
 
My TAP insisted on a minimum of 1.5 calibers of stability. Keep in mind that when the rocket goes through mach that the CP will move forward about 1 caliber. I wound up adding 53 oz. to the nose of my stock Punisher 4. The stretched version that I eventually certified with had 24 oz in the nose.

Chris - 2 questions:
1) was your punisher HED deploy?
2) when you say the CP moves forward ~1 caliber at Mach, are you referring to Mach 2?
 
My TAP insisted on a minimum of 1.5 calibers of stability. Keep in mind that when the rocket goes through mach that the CP will move forward about 1 caliber. I wound up adding 53 oz. to the nose of my stock Punisher 4. The stretched version that I eventually certified with had 24 oz in the nose.


At mach 1, stability is about 2.4 calibers and peak stability at motor burnout is about 3.6 (mach 1.4). Assuming -1 caliber for going transonic, that puts me in a range of 1.4 to 2.6. I should be good there.
stability sim.jpg

My dry weight just came in at 12.8lbs (everything except for motor + casing). I need to verify the CG as I feel it is likely a little more forward than expected after adding in the nomex blankets, which is good news for the stability calibers.
 
Body was prepped last weekend for paint. Luckily I had help from a friend that did car restoration, so my rocket is now sporting Dodge Viper Red. I also drew up a paint scheme just for fun if time permits to stencil on a few things.

Some of you may recognize something from Doc Brown if you look closely...

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Ground fire tests for your enjoyment. Final charge size was set to 2.0g from drogue and 3.5g for main.
[video=youtube;r1EwTA0kivc]https://www.youtube.com/watch?v=r1EwTA0kivc[/video]
 
Um, why is your main coming out of the booster and your drogue coming out of the payload?

Also, I would back those charges off a bit. Your drogue test almost completely stretched the harness, and in the air nothing will be holding back the airframe, so less powder will be needed. Just my :2:
 
My L3 flight was a success. The flight occured at ROCstock, lucerene dry lake, on 11/12/2017. Peak altitude was 14318 and maximum speed was mach 1.36. I decided to not include the onboard camera for this launch to reduce risk for this flight. Next up I'll work on a through wall camera design and start to assemble my Ultimate Darkstar.

[video=youtube;5hD0OGuq3ZE]https://www.youtube.com/watch?v=5hD0OGuq3ZE[/video]

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Congrats--awesome flight. Love that M1780NT; I got my L3 on one too. Comes up to pressure like an ON button.
 
Um, why is your main coming out of the booster and your drogue coming out of the payload?

Also, I would back those charges off a bit. Your drogue test almost completely stretched the harness, and in the air nothing will be holding back the airframe, so less powder will be needed. Just my :2:

I just noticed your reply. The main and drogue are in the right locations, main with nosecone and drogue with booster. The cords are also not at full extension, each ejection only pulled out about half of the 25 foot cord. The issue is that the cavities are fairly well packed. The good news is that it worked!
 
Great Flight! My son and I were there at Lucerne on Sunday and watched the launch, and watched as the rocket disappeared into the clouds. We found it on the other side of the road as we drove out of the lake bed!
 
Great Flight! My son and I were there at Lucerne on Sunday and watched the launch, and watched as the rocket disappeared into the clouds. We found it on the other side of the road as we drove out of the lake bed!


I'm glad you stuck around to watch the flight! The great staff that manages the ROC launch was kind enough to put up with my shenanigans as I prepped my first 75mm motor. It was a relief to balance it, more of a relief to see it take off, and the greatest relief was to recovery it safely on the other side of the road! My L2 attempt came down by the pad and was dragged TO that very same road. Lots of rash but someone managed to collect it for me before it worked its was on the road.
 
Um, why is your main coming out of the booster and your drogue coming out of the payload?

Also, I would back those charges off a bit. Your drogue test almost completely stretched the harness, and in the air nothing will be holding back the airframe, so less powder will be needed. Just my :2:

So, I just rewatched my ground fire test video to see what was wrong originally. Turns out I wrote "Drogue" when I was performing a main ejection charge test. I'll make corrections and reupload the video. Thanks for the catch!
 
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