BJBishop Jackson
← Back to current projects

Personal quadruped · In progress · November 2026

Mini Bish Bot

I’m building a low-cost robot dog around custom cycloidal actuators and a printed leg mechanism. My work connects mechanical design, fabrication, wiring, and closed-loop motor control.

Motor5010 brushless drone motor
Reduction20:1 cycloidal design
ControlPico + SimpleFOC

01 Mechanical design

From CAD
to a moving joint.

I designed the actuator around a 5010 motor, paired cycloidal discs, an output bearing, and printed housings. I’m refining bearing fits, disc flatness, stack clamping, and pin retention for smooth, backdrivable motion and repeatable assembly.

On the benchThe assembled actuator driving a printed lever.
My assembled cycloidal actuator CAD with output bearing and mounting flanges
The assemblyMotor, reduction, bearing support, and mounting interfaces in one compact package.
Exploded CAD view of my paired cycloidal discs, eccentric, output pins, motor and encoder
Exploded viewThe paired discs, eccentric, output pins, and motor stack.
Section view showing bearing support, the motor rotor, cycloidal reduction and encoder packaging
Inside the jointBearing support and encoder packaging, designed alongside the printed structure.

DFM drives the details: print orientation, part fit, fastener access, and assembly order. The goal is an affordable joint built from drone motors, printed parts, and inexpensive drivers.

02 Mechatronics

Command.
Measure. Refine.

I’m developing position and velocity control with a Raspberry Pi Pico, MT6701 magnetic feedback, and SimpleFOC drivers. My Python interface runs motion sequences and logs encoder response and drive effort. Joint wiring and CAN bus integration connect this work to the full robot.

Recorded bench plots compare position and speed setpoints with encoder response, alongside drive voltage over an 18-second motion sequence
Setpoints, encoder response, and drive effort from a recorded bench test.
More bench footage & wiring
Motor & driverTesting the 5010 motor with the low-cost control hardware.
The test setupLive control plots, motor operation, and the bench supply.
Pico and motor-driver wiring on the actuator test bench
Controller and driver wiring.
Close-up of encoder signal wiring and the actuator interface
Feedback wiring and joint interfaces.
Printed actuator prototype and wiring during assembly
Printed parts and assembly details.

03 My leg mechanism

Four printed members.
Motors at the hip.

The latest design uses a thigh, a lower leg with an integral knee lever, a motor crank, and a 100 mm connecting link. Two leg actuators share a rotating box; an inline hip actuator swings the assembly sideways.

170 mm thigh · 180 mm lower leg · 100 mm connecting link · 82 mm actuator spacing.
View the dimensioned linkageDimensioned linkage showing 170 mm thigh, 180 mm lower leg, 100 mm connecting link, 38 mm motor crank, 35 mm knee lever, and 82 mm actuator spacing

Built through iteration.

I began by tearing down a robot from the previous year, then used that experience to develop my own actuators, printed parts, and joint interfaces.

Next

Loaded actuator and leg testing, full quadruped integration, and simulation-to-real locomotion work with NVIDIA Isaac Sim and Jetson Nano onboard compute.