If you’ve ever built a model rocket, you’ll know there’s not a whole lot to them. Essentially it’s a cardboard tube, a plastic nosecone, some fins, and a little clip that will keep it riding the launch rail as it accelerates off the pad. Extra points awarded if you add in a parachute, but strictly speaking, even that’s a luxury. Stick an Estes motor in that thing and send it.
But pointing out that lightweight cardboard tubes can be tricky to ship without getting crushed, [Concrete Dog] has come up with HEXA, a clever model rocket kit that uses pre-scored cardstock instead. The immediate advantage is that this allows the rocket to be shipped as flat sheets of material, but as a secondary bonus, once folded into its final shape the rocket has an awesome hexagonal cross section.
As with a traditional kit, both the nosecone and fins are plastic. Except here they’ve been 3D printed in either PLA or PETG depending on their proximity to he hot and fiery area of the rocket. [Concrete Dog] says the printed parts are largely ready to fly as-is, but that some quality time with a piece of sandpaper and a coat of paint could improve the aerodynamics a bit if you were so inclined.
Ready for the best part? [Concrete Dog] has decided to release all of the design files for the rocket under the CERN Open Hardware Licence, meaning you’re free to reproduce and modify the rocket as you see fit. In fact, on July 24th, the HEXA rocket was officially certified as Open Hardware by the Open Source Hardware Association (OSHWA) — a first for a DIY rocket, as far as we can tell.
Is this the pencil rocket from the Mother series?
A friend of mine is printing some with a filament swap between a colour then brown filament to do a set of pencils!
gluing rings to the motor seems a bit strange to me. also, whats the point making the body flat pack when the nose cone isnt?
Yeah, putting a thrust ring on every motor instead of just once up inside the motor mount tube seems very wasteful.
It means you aren’t tied to a fixed length of motor. So I can fly estes b6 stuff but also Aerotech D composite in 18mm. You can’t do that with an internal thrust ring set up.
Most high-power rockets don’t use an “engine block” or thrust ring or whatever; without one, different lengths of motors can be used. With a 38mm motor mount tube, a rocket can be flown on a 6″ long H motor or a 20″ long J motor. The motor itself has an aft thrust ring.
Also… there’s no motor tube :)
A motor tube isn’t actually needed. I watched a 10″ dia rocket fly on an M motor with no motor-mount tube, just centering rings.
In a _traditional_ traditional kit, the fins and nose cone were balsa wood.
Agreed! Love building those older kits.
The dizzying smells of butyrate dope! The smack of a model rocket into the mud! GOOD TIMES!
> Stick an Estes motor in that thing
That’s cheating ;-) The real hard (and fun) part is to build and run the motor.
Over on this side of the pond that isn’t legal. Well you can technically do DIY hybrids but its a bit small for that.. but yeah solid rocket motor DIY illegal here.
Move.
Next thing you know, the fascists will ban firearms.
Vote with feet!
What a simple fix!
Thank you, kind internet citizen.
And then you get rid of all the extraneous junk and optimize the weight of it!
Making rocket candy is trivial. Making effective use of it…
WTF?
Does ANYBODY build model rockets without a warhead?
They are simple, how could you forget an item on such a short list?
What if one used Foam Core instead of Card Stock? I have built RC planes out of Foam Core. They are light weight and rugged.
https://makerworld.com/en/models/518787 I printed one :)