Angstron DT 6in glider

thingiverse

Angstron 6in CLG is my crowning achievement since 2017 for CLG events. My top model soars consistently at 72 seconds outdoors not because its sink rate is exceptional, but because it can reach incredible altitudes during launch, weighing in at a mere 3.4 grams. This demands an extremely aggressive trim with AFT CG and neutral rudder, which I could only achieve by harnessing the flexibility of the tail boom. The original model is fixed, so if it encounters a thermal, it's gone for good. Hence, I decided to create a DT version. All versions utilize identical flying surfaces as the original, all precision-cut using CNC milling technology with varying thicknesses within a +/- 0.2mm range according to balsa density. This consistency enabled me to implement gradual improvements in fuselage and mechanism design. The DT concept is straightforward yet effective: a string and rubber run from the bottom of the fuselage over the wing, loop around the boom right at the wing's trailing edge, and return to the nose where they meet the viscous damper. The wing is attached to a support that hinges to the fuselage via an M2 nylon bolt (later glued and sanded). A 10mm rubber connected to a 0.4mm wire hook in the wing rotates it to a 45-60 degree negative incidence. Version 1 was created as a concept but proved impractical due to excessive flexibility and a nose-heavy design. Version 2 featured a timer after the launching hook, a hole for attaching the DT string, and flew reasonably well but bunted hard during launch, compromising altitude. It was highly sensitive to rudder input, with some flexibility coming from the DT system. Version 3 boasted a shorter nose, improved wing support, a three-panel wing (flat center), a fuselage that enclosed the boom, and was printed at 30% infill with 2.5mm at its thinnest section. The thicker DT rubber helped reduce bunting, but it still wasn't as efficient as the fixed model. Version 4 saw an increase in fuselage thickness to 2.6mm, a shorter boom by 10mm, and an elevator airfoil facing upwards. Bunting was no longer noticeable, but glide performance suffered due to excessive weight at 4.2 grams. It remained sensitive to rudder input, more so than the fixed model. Version 5 - my final masterpiece - boasted a thinner wing (0.4g weight reduction), a 2.8mm fuselage with an altered infill and shell strategy to save 0.15g, a longer wing support to prevent fuselage flexing during DT attachment, and a final weight of 3.7 grams. This model showed no signs of bunting, flew consistently, climbed exceptionally well, and glided as expected. Have fun!