10/22/08

Announcing High-5

Presenting my latest project, High-5, a five motor cluster that goes HIGH!! It is 100% high-power, able to fly on I's J's and K's, no less. This is my first build that cannot be flown as a model rocket.

Physical description:
  • Central 54mm motor mount (for I through K motors), and 4 outboard 29 mm motor mounts (for G's and H's)
  • 70 inches long, 4 in diameter inches at the nose base, down to 3 inches, back out to 4 inches at the "business" end
  • Should be able to carry 8 oz of payload (like cameras, transmitters, altimeters) to over 5000 feet!
  • Projected weight: 8 pounds (with maximum power)
  • 2 or 3 stage configuration (a small onboard timer ignites outboard motors at a preset time interval after ignition)
  • Estimated completion date: May, 2009
I've been working on it for a couple months now, and already it is beginning to take shape!


4 comments:

Murdock said...

I saw your build thread over on TRF, its looking very nice. You've advanced pretty quickly it looks like. Hopefully I'll get some build time in soon so I can start on a larger project as well.

skycopp said...

Very Nice. Good job on that!

R2K said...

Really nice. I bet you could get this thing going on 3 G motors... it doesnt look too big. Use the new G80 maybe?

DTH Rocket said...

3 G motors? My first reaction was "Naw, this is way too heavy for that." But further thinking has lead me to believe it might be a good idea for it's first flight.

Original estimates were that this would be 8 pounds with engines loaded and payloads installed. If I were to put 3 G80's in it, that would be a combined average impulse of 240 Newtons, divided by 4.45 is 53.93 pounds. I've heard a good rule of thumb is a 5:1 thrust-to-weight ratio, so 53.93 lbs / 5 would equal 10.78 lbs. That's more than this rocket would ever weigh, especially with only G motors installed.

Then I went into RockSim and loaded it 3 G80 motors (this is the old kind I think) and it managed to pull off 1,300 feet!

The only thing is that you can't get certified on multiple SU G motors, I need to use a full-fledged H or I motor, since I'm going to have one larger motor and several smaller motors it would be safer to airstart the smaller ones, and in order to maintain a 5:1 thrust-to-weight ratio that one motor will have to be fairly large. Unless of course I choose to use 3 or 5 H motors... That's an idea.... But with clusters, cost starts adding up quick!

Thanks for your comments
~Daniel

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