The Martin Titan Mk. 2

I have been working on designing rockets lately using my 3D Anycubic Photon printer. This is the third rocket in the series, after the Taurus and the Artemis. The Titan was planned to be a large, simply designed rocket, made of cheap materials for ease of assembly and reuse.

For the body, I started with a regular old paper towel tube. The inside diameter of the tube just happened to be 42mm, as fate would have it (the answer to life, the universe, and everything, as well as my current age in years). Using this as the core, I designed a hollow nose cone, upper and lower engine mounts, and fins. All of these are original designs adapted from my work on the prior Taurus and Artemis designs.

3D design (hollow view) of Titan’s basic pieces. The fins are printed 3 times.
3D design of Titan’s basic pieces. All of the parts were designed in Tinkercad. Outside diameter of the core pieces are 42mm.

After designing the models in Tinkercad, it was time to print. I use Chitubox for slicing. The slices were set to print at .05mm (50 micron), with 60s bottom exposure, and 8s normal exposure.

I used Elegoo Water Washable Red (Clear) resin for the core pieces, and Elegoo White Resin for the fins. I like using the water washable quite a bit because it’s a bit less brittle after printing, and seems to hold up to stress better, so I’ll be using the water washable for all of the parts from now on.

Next, I glued the fins to the tube using hot glue. I like using hot glue for some parts because it makes a more flexible bond, which helps when the rocket undergoes the stresses of launch and recovery.

Titan Mk. 2 with fins glued to paper towel tube.
Titan Mk. 2’s core pieces printed in water washable red resin.
For the launch tube, I just cut a section from a normal plastic straw, and hot glued it to the side of the rocket tube.
After putting a few coats of aluminum colored spray paint on it, I glued the upper and lower mounts in with Elmer’s glue. The easiest way I found was to glue the outside of each part, put a rocket motor in for sizing (B6-4 used), the slide the whole unit in until the bottom mount is flush with the base.
I used an Estes parachute and shock cord, which can be purchased in bulk directly from Estes, or at Michael’s. The end of the shock cord is hot glued to paper, then hot glued to the inside of the tube.
Titan Mk. 2 fully assembled. I added 6 pieces of loosely crumpled wadding. You can also use a single ply sheet of toilet paper as a single piece of wadding (just crumple and add 6 of them to the bottom of the tube, above the engine).
The Titan Mk. 2 is fully assembled and ready for launch!

The STL for the entire build is available for download below (free!).

The Martin Space Program family photo.

Launch Day

In all, we had four launch attempts on the original Titan rocket.

FIRST LAUNCH ATTEMPT

Igniter failed to spark resulting in no launch.

SECOND LAUNCH ATTEMPT

Rocket ignited, launched about 6 feet up, but upper engine mount was not secured inside the rocket tube, so the force of the rocket engine pushed the chute and nosecone off, resulting in an immediate drop. The rocket melted a small part of the parachute, but otherwise the rocket was unharmed. Re-glued the engine mount, and reset the rocket.

THIRD LAUNCH ATTEMPT

Igniter failed to spark resulting in no launch.

FOURTH LAUNCH ATTEMPT

This launch was flawless. Ignited, left the pad, and shot up to an apex of a little over 300 meters. Seconds later, the chute was deployed, and the entire rocket descended slowly for a gentle landing in the field. The melted parachute cause it to land a little quicker that expected, but still within tolerances (no damage).

Video of the launch of the Titan Mk 2 on May 24, 2020 at Chuck Rodgers Park in Jacksonville, Florida.

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