[Motor Purchased] 5 inch diameter rocket and a CTI O3400.

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View attachment 174499

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This is based on the rocket weighing 50 pounds minus the motor. I do not have a final weight yet. I am just predicting and hoping the rocket weighs less then 50 pounds when finished without motor. That altitude is really high. I did not expect a rocket of this size to go that high on that motor. I am not complaining just underly optomistic about altitude. I was banking on around 20K. But 27K is insane!!! I'll take it!!! If anyone has a suggestion on getting a better sim please let me know.
 
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50 lbs seems a lot for this project, but you built it and should know. The altitude can be doable.

I launched a 6 in. diameter 12 ft Ultimate Wildman that weighed 64 lbs ready to fly & hit 24, 800 ft. [N-5800]

You have more total impulse , smaller diameter & when loaded if less weight...yep, your there!

Good luck with your flight!
 
I don't see how that rocket could weight 50 pounds unless you have really thick walled tubes. Scott Hertel's rocket was also 5.5 inches in diameter, I'm thinking you might hit 34K depending on your final weight.
 
Very Cool!! I am excited to finish the rest of the rocket!!!! I can now say I will be going Boldy where I have never gone before!
 
Now since I am expecting close to 30,000 feet in altitude what is the best course of action for ejection charges at apogee. I have heard BP charges working fine at that altitude but use caution.
 
Its been a while. Got rocket weighed.

35.71 pounds without motor
72.84 pounds on pad
10.48/1 thrust to weight ratio
21,062 Newtons O3400 IMAX
1,851.4 (ft/s)
28,668 feet in altitude
1.6583 Mach
.508 CD
 
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Wayco said:
Jim Jarvis has an excellent article on high altitude ejection charges here:
https://www.rocketryfiles.com/files/Technicalarticles/Jim_Jarvis_Highaltitude_deployment_2013.pdf

Really looking forward to seeing this rocket launch! 40 days and counting to Airfest.
Click to expand...

I passed that article along to Andrew a while back with a recommendation to increase the BP by 25% or so with the surgical tube. I'm not so sure about the long length of it though??. I would speculate that it would make the BP more prone to being scattered. The longer length of charges of increasing weight is why I started investigating the method in the first place.

Jim
 
JimJarvis50 said:
I passed that article along to Andrew a while back with a recommendation to increase the BP by 25% or so with the surgical tube. I'm not so sure about the long length of it though??. I would speculate that it would make the BP more prone to being scattered. The longer length of charges of increasing weight is why I started investigating the method in the first place.

Jim
Click to expand...

I think the threaded brass tube would be a better choice. I'm just not sure how to seal the ejection gasses out of the avbay. I toyed with a design using 3/4" PVC caps that were threaded with a short piece of pipe through the aluminum bulkhead Wildman makes, but I couldn't come up with a good method of sealing the pipe, so went back to my terminal blocks mounted on the outside:
088.jpg


Those cups hold about 8 grams of BP, but I only use 3, so plenty of room for expansion/combustion before it exits the chamber. I seal the top with electrical tape after stuffing some dog barf in there. No scientific research done, just ejection charge tests done at sea level, but I get good results in a 4" tube 20" long.

 
Sorry for getting back so late. I received word that Bob Brown Prefect of Kloubusters has cleared me for flight!!! Whoop!! I plan on launching this beast on Saturday August 30th around noon.
 
andrewlathrop87 said:
Sorry for getting back so late. I received word that Bob Brown Prefect of Kloubusters has cleared me for flight!!! Whoop!! I plan on launching this beast on Saturday August 30th around noon.
Click to expand...

Great news! Look forward to seeing your flight.
 
Awesome flight! I saw and heard this beast launch from over a mile away, as I was recovering another rocket. Got the heads up on the FM radio and looked up in time to see it launch. What did you finally decide to use for your ejection charges? I'm planning to build a DS Ultimate and fly big motors in it, the O3400 might be in the agenda for this rocket.
 
Awesome rocket, awesome motor! This flight pretty much captures why I love rocketry. It doesn't get much better than putting a lot of thought and effort into designing and building a rocket and then capping it off with a successful flight! Congratulations on a spectacular flight!


Sent from my iPhone using Rocketry Forum
 
[video=youtube;hLG2HkUzp_E]https://www.youtube.com/watch?v=hLG2HkUzp_E[/video]

[video=youtube;OqF5FE5pJnY]https://www.youtube.com/watch?v=OqF5FE5pJnY[/video]
 

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