SUPPORTING DOCUMENTATION / ENGINEERING CALCULATIONS

Engineering calculations.

Engineering calculations.

This page contains the supporting hand calculations used throughout the development of the 6-DOF robotic arm. These calculations were used as first-order engineering checks alongside physical testing and design iteration.

01 — WORST-CASE SHOULDER LOADING

Estimating the theoretical payload limit at full extension.

Estimating the theoretical payload limit at full extension.

The shoulder was evaluated in the fully extended configuration, where the payload produces its largest moment about the joint. Available shoulder torque was estimated from the NEMA 17 motor torque, 25:1 cycloidal reduction and assumed drive efficiency.

7.5 N·m

AVAILABLE OUTPUT TORQUE

≈1.7 kg

THEORETICAL PAYLOAD LIMIT

0.5 kg

SELECTED DESIGN PAYLOAD

≈3.4×

THEORETICAL PAYLOAD MARGIN

ORIGINAL HAND CALCULATION

02 — PRINTED LINK BENDING

Checking the printed link under worst-case bending.

Checking the printed link under worst-case bending.

The arm link was simplified as a cantilever beam and evaluated using the downstream component loads and their respective distances from the shoulder.

KEY RESULTS / TO BE ADDED

ORIGINAL HAND CALCULATION

03 — LINK DEFLECTION

Checking whether the printed structure was sufficiently stiff.

Checking whether the printed structure was sufficiently stiff.

The same simplified loading model was used to estimate deflection caused by the downstream loads.

CALCULATED DEFLECTION / TO BE ADDED

ORIGINAL HAND CALCULATION

04 — KINEMATIC MODEL

Defining the robot geometry for forward kinematics.

Defining the robot geometry for forward kinematics.

The DH parameters were used to define the robot’s joint and link relationships before implementing the forward-kinematic model in MATLAB. The resulting model was later used to evaluate TCP position and generate the robot’s reachable workspace.

ORIGINAL HAND CALCULATION