4" Min Diameter Rocket

All,

Last weekend at BALLS myself and Oberth flew a 4" minimum diameter rocket on an ~N5000 EX motor. The rocket was named "Honey Badger Don't Care" after the YouTube video and because I designed and built the rocket to be a tough testbed rocket that would provide a learning experience from which we could leverage techniques and processes for future, more high performance projects. The rocket consists of a 60" FWFG Performance Rocketry Tube with a FWFG von Karman nosecone.

The motor was a 98mm case with radial pins holding the nozzle and forward closure. I need to consult my notes for the area ratio of the nozzle, but it was pretty high as far as EX motors go. The formula was all around moderate; solid loading, aluminum content, and ISP (235s), except for pressure which peaked at over 1000PSI.

I am going to throw up some post flight pictures of the rocket, some construction pictures and some pictures from the previous flight when I get some time but for now the BALLS flight:

Peak Alt: 40,000ft
Peak Velocity: Mach 2.5
Peak Acceleration: 42G

We'd like to thank tfish and burner for their support during this and the last flight. Having the pros to consult when you're trying to fly rockets like this certainly makes things a lot easier.

Awesome! Congrats! I'm looking forward to more details!

Very cool! I'd like to hear more about the motor (in the research forum?).

Very impressive flight, AWESOME motor!

Thanks for the kind words. I grabbed a few more pictures off of my phone: one of the grains in front of some grains I cast for a friend and one of the rocket pre and post flight. The rocket showed signs of significant aerodynamic heating especially in the areas around the fins as was expected. Although no high temperature epoxy was used anywhere on the rocket, it was coated with high temperature paint in some areas - those that are black. Hot pink, although slightly embarrassing, was chosen as we thought it would make the rocket visible against every surface. There was about a dime sized peice of carbon that peeled up in one spot near the tip of one fin, but otherwise the fins were undamaged save for the paint that peeled off.

butalane said:

Thanks for the kind words. I grabbed a few more pictures off of my phone: one of the grains in front of some grains I cast for a friend and one of the rocket pre and post flight. The rocket showed signs of significant aerodynamic heating especially in the areas around the fins as was expected. Although no high temperature epoxy was used anywhere on the rocket, it was coated with high temperature paint in some areas - those that are black. Hot pink, although slightly embarrassing, was chosen as we thought it would make the rocket visible against every surface. There was about a dime sized peice of carbon that peeled up in one spot near the tip of one fin, but otherwise the fins were undamaged save for the paint that peeled off.

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Very cool, I really like the four fin design. What made you guys decide to go for that configuration?

The rocket had flown once before this flight and proved its usefulness as a tough rocket. This flight was a shakedown and had a ~13,000Ns N3800. Unfortunantly the nozzle collapsed about 2s into the burn and created a massive 80G spike that looked, from the ground, like a CATO. Luckily this was not the case and in fact both snap rings remained in the groove and only the nozzle and propellant had ejected. The rocket reached a 15,000ft apogee and a max velocity of a little over mach 1. When we picked the rocket up we realizd the integral thrust ring on the case had actually stretched the composite tube and forced its way up into the rocket until stopping at the fins. We were a little concerned we had made a mistake in the mixing process, but in comparing the curve to the thrust stand data we decided the motor was performing nominally and the nozzle, with many previous firings, was to blame.

To repair the rocket I cut the damaged airframe and epoxied a new piece on and cleaned up the fillets as the aft ends of them were slightly chipped.

Liftoff picture link from Ken Adam's Got Rockets Page (gotrockets.com): https://gotrockets.com/galleries/2012/mudroc12/photos/_MG_5902.jpg

):

Is the nose tip missing in the post-flight image, or is it just me? Was it removable?

You need some better beer, my friend.

Chris,

It is, it somehow fell off somewhere along the ride. I had it epoxied and wrenched down, but it popped lose after the first flight and I never re-epoxied. I thought wrenching it down would be enough ... oops.

Nick,

Ran out of Miller Lite so I had to downgrade for the picture.

Thought I'd throw in a few more pics just for fun

Pinned Case


"Ablative" exit cone


Slight composite damage

Oberth said:

Thought I'd throw in a few more pics just for fun

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Dirty feet?


Nice Flight....

Real men fly pink rockets! Love the design and sounds like a really massive motor.

maybe something weird happened..like his shoes fell apart while out digging in the sand.

Tony

tfish said:

maybe something weird happened..like his shoes fell apart while out digging in the sand.

Tony

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He's wearing sandals?

Another interesting addition to this project was the use of a standard geometry dual deployment setup. Since the motor was 48" long most of the 60" tube was used up. To make up for the lack of space I made an altimeter bay that fit half the coupler tube. The remaining half, which faced towards the aft, was left for the drogue recovery tether. The forward end of the altimeter bay capped the coupler tube and was itself capped by the nosecone coupler (the nosecone holds the tracker, chute and recovery tethers). The altimeter sled shown in the picture slid into the forward end of the coupler onto a plate that was permanently attached to the middle of the coupler along with threaded rod for attachment during flight.

The benefit of this setup was the entire rocket was essentially double walled. The top of the motor was in direct contact with the altimter bay/coupler which was in direct contact with the nosecone coupler. This gave me extra confidance in the design without adding much weight as the coupler and nosecone were needed anyway.

New Ocean said:

Real men fly pink rockets! Love the design and sounds like a really massive motor.

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Estes has a Pink Rocket called the "Dink". oint:

Look, this Guy built one.:https://www.rocketryforum.com/showthread.php?53752-Sometimes-I-just-have-to-E2X&highlight=Estes+Dink

butalane said:

Thanks for the kind words. I grabbed a few more pictures off of my phone: one of the grains in front of some grains I cast for a friend and one of the rocket pre and post flight. The rocket showed signs of significant aerodynamic heating especially in the areas around the fins as was expected. Although no high temperature epoxy was used anywhere on the rocket, it was coated with high temperature paint in some areas - those that are black. Hot pink, although slightly embarrassing, was chosen as we thought it would make the rocket visible against every surface. There was about a dime sized peice of carbon that peeled up in one spot near the tip of one fin, but otherwise the fins were undamaged save for the paint that peeled off.

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What was the type of high temp paint that you used? Also what temp is it rated for? Thank you!

enjoyed the post, and am now enjoying you tube Honey Badgers

Round 2:

https://www.rocketryforum.com/showthread.php?58793-Honey-Badger-2-Build-Thread-and-Flight-to-57k!