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 Tip Anchor Cap
This is the end cap of the 'SG90 Tendon-Driven Continuum Trunk Arm' kit. It is a Ø50 x 4 mm flat-bottomed disc that sits on the dome of the last vertebra. Its blind 4.3 mm bore takes the 4 mm OD PTFE backbone, which you lock with an M3x8 set (grub) screw in a radial 2.6 mm hole at z=8. You drive that screw with a hex key through a 3.4 mm access tunnel in the +X boss. Three 1.8 mm tendon holes at R20 take 0.8–1.0 mm braided line, and each has a Ø4 knot counterbore on top. Two Ø9 bosses at ±14 mm hold M3 heat-set inserts (4.0 x 6 mm bores). Their tops are flush with the Ø14 centre boss at z=18, so a payload bolts onto one flat plane.
Rolling-Dome Trunk Vertebra
A Ø50 x 3 mm spine disc for the 'SG90 Tendon-Driven Continuum Trunk Arm' kit, printed ×8. It has a Ø12 hub topped by a R7.5 rolling dome with its apex at 12 mm, which sets the 12 mm stacking pitch. The 4.6 mm bore rides loosely on the 4 mm OD PTFE backbone so each segment can tilt. Three chamfered 1.8 mm holes at R20 guide the 0.8–1.0 mm braided tendons, and three Ø10 lightening holes keep each disc to about 6 cm³.
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 Tower Column
Hollow riser for the 'SG90 Tendon-Driven Continuum Trunk Arm' kit. It is a 60 mm OD tube with a 2.4 mm wall and stands 70 mm tall. The Ø84 mm base flange bolts to the servo deck with 4x M3 on a 36 mm radius. The Ø76 mm top flange carries the root plate on 3x M3 at R34, with 5.7 mm hex nut pockets underneath. Three 28 mm pointed-arch windows let the Bowden tubes and wiring pass through. It prints upright with no supports.
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.