VaDiM 1

thingiverse

VaDiM stands for Variable Direction Mount, a term essentially synonymous with Thrust Vector Control in PR circles. It's a 3D printed mechanical unit that gets mounted inside a model rocket fuselage (10cm diameter) and paired with 2 servos to accurately and reliably change the direction of a F-class model rocket motor. This enables active stabilisation and control of the rocket. Structurally, the VaDiM module consists of three main components: the outer manifold, which connects the entire system to the rocket's fuselage; the outer gimbal, containing 2 servos; and the inner gimbal, holding the rocket motor in a compliant grip. The two gimbals pivot on a simple assembly of 4 small screws, 4 bearings, and 8 nuts, 4 washers. Fully designed in open-source 3D software "Blender," implementing a non-destructive workflow heavily influenced by Chipp Walters' tutorials. One core design goal was to ensure parts can be successfully 3D-printed without support materials. However, this ambitious goal crippled the first prototype of VaDiM due to servos being too weak from one side only. The solution came after re-designing the outer gimbal completely. Instead of printing the part vertically, any arbitrary plane could be used as a printing plane. A vertical 45° angle plane was set perpendicular to the bisector of the two planes defined by the servos. This ensured printability over the critical region, enabling a complete shroud over the servos held from four directions. The outer gimbal is the most complex part, and this breakthrough enabled successful printing without support materials.