Print the parts
Practical notes for printing the mechanical parts. STL files live in
../model/meshes/; the OnShape source is linked from
BOM.md.
Settings
Section titled “Settings”PLA or PETG, 0.4 mm nozzle, 0.2 mm layer (Bambu Studio defaults). Use ‘Tree’ supports for the enclosure (base, lid) and the arm.
Pendulum link — pause printing to insert the coin
Section titled “Pendulum link — pause printing to insert the coin”The pendulum link has a slot sized for a UK 2-pence coin (7.12 g) as the tip mass. Configure your slicer to pause on layer 21 — drop the coin into the slot, then resume. The next layers seal it in.
If you skip the pause, the link prints with an empty void where the coin
should be: its mass and inertia then disagree with what
model/model.urdf says, and the policy will not
transfer from sim.
Soldering note
Section titled “Soldering note”Cut your hookup wires slightly longer than you think you’ll need. Excess length is trivial to manage; a wire that’s a few millimetres too short turns the next solder joint into a fight.