Test speed
500 RPM
Problem
What the build needed to solve
My contribution
Launcher-wheel CAD, supercapacitor enclosure shell, front armor packaging, feed-path clearance review, press-fit interface revision, M3 retention update, and 500 RPM prototype test support.
The launcher subsystem had to fit inside a constrained RoboMaster gimbal while preserving projectile feed-path clearance and motor-interface alignment. The key mechanical risk was not only part strength, but whether the printed wheel, supercapacitor shell, and front armor could package cleanly without interference or weak retention.
Constraints
Design boundaries
Fit within the existing RoboMaster gimbal envelope.
Interface with the DJI M2006 motor package.
Maintain approximately 20.5 mm projectile feed-path clearance.
Use FDM-printed PLA for prototype launcher components.
Preserve wheel symmetry for prototype spin testing.
Improve retention beyond press fit after integration review.
Limit claims to the 500 RPM prototype condition, not high-speed launcher qualification.
Build log
Design evolution
Design decisions were driven by packaging constraints, projectile clearance, motor-interface retention, and prototype test feedback.
Revision
Failure mode
Design change
Result
Initial packaging
Launcher hardware had to fit inside the gimbal envelope
Modeled wheel, armor, and supercap shell around existing geometry
Established package envelope
Feed-path review
Projectile path risked local interference
Maintained 20.5 mm clearance through launcher path
Reduced feed interference risk
Motor interface
Press fit alone was weak as a retention assumption
Revised 0.122 in / 3.10 mm interface with M3 screw retention
Stronger assembly confidence
Prototype test
Needed low-speed functional check
Tested with DJI M2006 at 500 RPM
Confirmed prototype-level operation only
Details
Technical details
Drive system
DJI M2006 motor
Prototype material
FDM-printed PLA
Flywheel outer diameter
78.0 mm
Flywheel thickness
22.5 mm
Flywheel mass
~0.13 lb
Motor interface
0.122 in / 3.10 mm press-fit interface
Retention update
M3 screw retention added from flywheel base
Feed-path clearance
~20.5 mm
Simulation
Onshape preliminary screening for 500 RPM condition
Related packaging
Supercapacitor shell and front armor structure
Testing
Results
Flywheel OD
78.0 mm
Feed-path clearance
20.5 mm
Retention update
M3 screw retention added
The prototype was tested at the DJI M2006 motor's 500 RPM condition. The assembly maintained approximately 20.5 mm feed-path clearance, and the motor-interface design was revised from press fit alone to press fit with M3 screw retention after integration review. Onshape simulation was used as preliminary screening for the 500 RPM prototype condition, not as high-speed launcher qualification.
Scope note: This was a 500 RPM prototype test, not high-speed launcher qualification.
Reflection
Engineering lessons
- Press fit alone was not a strong enough retention assumption for a rotating prototype.
- The most important design constraint was packaging: feed-path clearance, wheel symmetry, motor interface, and surrounding gimbal geometry had to work together.
- Future work should include measured runout, documented balance checks, guarded spin testing, and stress screening before using the design with higher-speed motors.
Gallery
CAD, fabrication, and test views
CAD
Launcher packaging inside constrained RoboMaster gimbal envelope
Physical Assembly
Prototype hardware during integration review
CAD
78.0 mm OD PLA launcher-wheel prototype
CAD
Printed enclosure shell packaged behind front armor
Preliminary Onshape Simulation
Preliminary Onshape screening for 500 RPM prototype condition
Preliminary Onshape Simulation
Screening result used for prototype review, not high-speed qualification