What weighs 2.5g and flies 430ft?

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Digit
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What weighs 2.5g and flies 430ft?

Postby Digit » Wed Mar 07, 2018 8:24 pm

A 6mm minimum diameter rocket, that's what :mrgreen:

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After a patient wait, Australian Rocketry have woven their magic and sourced me a packet of Quest micro motors (1/8A3-1)
These little guy's are 6mm diameter and 26mm long, with a total impulse of 0.218n-s and a burn time of 0.772 seconds!

What to build to fly them in? The smallest rocket in the country was the obvious answer! So I jumped into Open Rocket and drew the shortest airframe possible, leaving only 3mm for a nosecone shoulder, and then began trying a ton of different fin designs until I found the one that provided the best stability.

When I saw my design sim to 430 feet I knew I wouldn't be seeing this rocket again, so I decided to make six of them to be safe (the motors come in a six pack).

Now onto the materials - where the hell am I going to source a 6mm airframe I thought, then I remembered keeping a tiny cardboard tube that the igniter shipped in for the DMS motor I launched at MARS last year. I dropped the vernier's down into it and to my pleasure read 6.9mm, and it was even the right length to make seven air frames! Time to get to work.

After cutting my air-frames out I had the idea to use a length of 6mm balsa dowel to manufacture nose cones and secure them into place with a tiny shoulder. After unsuccessfully trying to sand down the first nose, I needed to come up with a better solution. That's when I noticed the pencil laying beside the dowel was the same diameter! Straight into the big sharpener with the balsa and I had a perfect cone within two seconds. I then parted it off with a pull saw and manufactured the remaining noses.

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A test fit into the air frames and it was time to get thinking about fins.

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I decided to use an old manila folder as its a nice strong card, but still relatively thin. I marked out 24 of the little guys and spent the next hour or so cutting them all out.

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Perfect shape lol.

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I then assembled the first rocket together and cut a tiny piece of a drinking straw as a launch lug. When I lifted the rocket up off the bench I immediately began laughing, what have I done?!

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After building the remaining five I needed to fabricate some sort of jig so I could paint these things, so I murdered a coat hanger.

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The only thing left to do now was name the rockets. Seeing as there was 6, I decided to make these my little tribute to the Rocket Boys of the Big Creek Missile Agency and launch all six at the same time.

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Be sure to come to QRS' Flames, Smoke & Noise Launch this month to see the tiniest drag race in history 8)
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kopius
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Re: What weighs 2.5g and flies 430ft?

Postby kopius » Wed Mar 07, 2018 10:42 pm

That is so good! We will have to forward that QRS Honorary members, Homer and Linda Hickam ;-?

Looking forward to seeing them fly. You’re welcome about the motors too :-)


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SpaceManMat
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Re: What weighs 2.5g and flies 430ft?

Postby SpaceManMat » Thu Mar 08, 2018 10:16 am

Way cute. I recon you should try drag racing them, you should be able to keep an eye on the group of them easier. As long as they fly the same you’ll be able to recover the whole group fairly easy.
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OverTheTop
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Re: What weighs 2.5g and flies 430ft?

Postby OverTheTop » Thu Mar 08, 2018 10:51 am

Very cute.

How about deleting the launch lug and building a launch tower for extra altitude? :D
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str8up
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Re: What weighs 2.5g and flies 430ft?

Postby str8up » Thu Mar 08, 2018 5:37 pm

Or throw away 5 nosecones, stack them on top of each other and have a 6 stage rocket.

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Re: What weighs 2.5g and flies 430ft?

Postby krusty » Sat Mar 10, 2018 8:05 am

Very cool :) MicroMaxx are a lot of fun !

I had Blake hunt down some MMX motors for me a while back, too :)

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Digit
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Re: What weighs 2.5g and flies 430ft?

Postby Digit » Mon Mar 19, 2018 8:44 pm

The Big Creek Missile Agency launch again :D

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(Photo Credit: Jeff Cheales)

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Re: What weighs 2.5g and flies 430ft?

Postby october sky » Tue Mar 20, 2018 4:41 pm

This was one of the coolest things ever. The work you put into these tiny missiles is awesome. As a LCO on the day I saw them scatter right in front of me....so fast that I couldn't see any..... 8) :lol:
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Re: What weighs 2.5g and flies 430ft?

Postby OverTheTop » Tue Mar 20, 2018 5:27 pm

Great flights!
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