Print. Test. Fly.

A major issue was the low reliability of the fully redesigned cargo released system. Due to position of springs and the alignment rods on each corner of the release plate, sometimes the angle and friction were high enough to stopn the release mechanism from fully releasing. Although this could be solved through iteration, there was not enough time and I decided to shift focus to testing. Due to the poor calibration of the force sensors for engine thrust, readings were not accurate enough. However, this is easily fixed through software.

Given that the vehicle was not designed using CAD, a major issue present was the imprecise path the flaps followed during release and retraction. Also affected by the lack of precision due to parts being handmade. However, the retractable flap design helped me a lot during the design of the aerodynamic surfaces of the Itzanma III capsule.

The capsule’s power supply had to be changed right before flight due to the first stage’s lower thrust than anticipated. This didn’t hurt the vehicle. The capsule’s cheap ultrasonic sensor was mainly affected by the ground surface and weather conditions, so it failed to produce readings precise enough for a successful landing. However, the engine ignition was successful, proving what could be done with limited resources.

Ran into normal issues with component tolerances due to a lack of precision on some spec sheets, magnified through 3D printing. Also dealt with an issue on the 7.4V-to-5V step-down converter to make sure the microcontroller and 5V components could operate safely. Faced some problems printing the wheels with TPU as well, but it turned out to be a slicer setup issue rather than a design flaw.

This was my first time 3D printing and designing, so I had a lot of trouble with tolerances. I also didn’t know about print layer orientation, so some parts that were exposed to high forces failed. All of these problems were solved through iteration, but most importantly, they taught me many skills that I now frequently use when working on other projects.