Overview
After the 3D-printed gimbal melted, I machined an all-aluminum thrust vector control mount on my own CNC mill, iterating through three designs before landing on one that balanced machinability with performance. I sourced precision HV93i metal-gear servos as actuators and used plain bearings to kill the tolerance stack-up from machining, hitting +-0.1 degree 2DOF accuracy, and wrote the control code through STARLIGHT to drive it. Completed in early 2024.
Technical materials
What I learned
- Iterated through three CNC-machined aluminum TVC gimbal designs, rejecting the first two for manufacturability and assembly-complexity issues before converging on a design that balanced machinability with performance
- Designed for CNC manufacturability - splitting part geometry into pieces sized to standard aluminum stock thicknesses - after an initial over-ambitious design proved unmachinable on my own mill
- Selected precision HV93i metal-gear servos over hobby-grade plastic servos, and used plain bearings to eliminate machining tolerance stack-up, to hit +-0.1 degree 2DOF actuation accuracy
- End-to-end CAD design, BOM production, CNC machining, and assembly to reach a final product, including published technical drawings and a Fusion 360 assembly animation
- Wrote the control code through STARLIGHT to drive the gimbal at this accuracy, and built dedicated test rigs to validate and measure performance
Project related blog posts
- All-Aluminum Thrust Vector Control: A Journey
- STARLIGHT V2 and thrust vector shenanigans – HORIZON II design process