Heads up: many models on this page are AI-generated or uploaded untested. They may be misconfigured for the intended application — check the dimensions and tolerances, and verify or edit the model before printing or relying on it.*
Trunk Root Plate
This is the root plate of the 'SG90 Tendon-Driven Continuum Trunk Arm' kit: a Ø76 x 8 mm disc that bolts to the tower's top flange with 3x M3 at R34. It clamps the 4 mm OD PTFE backbone in a 4.3 mm bore, locked by an M3x8 set screw threaded into a radial 2.6 mm hole on +X at mid-height. It also has three 4.3 mm x 6 mm Bowden tube sockets at R20 that open downward and step into 1.8 mm tendon holes. The first rolling dome, a Ø12 hub with an R7.5 cap, peaks 9 mm above the plate top.
Trunk Servo Base Deck
This is the foundation of the 'SG90 Tendon-Driven Continuum Trunk Arm' kit. It is a Ø140 mm deck, 3.5 mm thick, with a 32 mm skirt that has a 2 mm wall. It holds three SG90 micro servos in 22.8 x 12.4 mm through-pockets on a 52 mm radius. Each pocket has 2.4 mm M2 tab slots that cover 26–30 mm tab spacing. The trunk tower bolts to the deck with 4x M3 through 3.4 mm holes on a 36 mm radius, with captured 5.7 mm hex nut pockets under the deck. The deck also has a Ø44 wire pass-through, three 3.4 mm radial slots (R46–R60) for the Bowden guide blocks, six lightening windows and three 16 x 10 mm cable notches in the skirt. It prints upside down with no supports, and the hole pattern is mirror-symmetric, so it reads the same either way up.
Antagonistic Tendon Twin-Groove Capstan
A 44 mm OD, 36 mm tall capstan pulley for a 5 mm motor shaft, with two separate 36 mm cable grooves so one shaft can drive a push-pull tendon pair for a zero-backlash robot joint. The shaft bore is 5.2 mm and locks with an M3 set screw into a captured M3 nut. Each groove has a 2.2 mm cable port into a hollow internal ring, so a crimped ferrule anchors each cable on its own.