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.*
608 Pivot Whiffletree Load Equalizer Bar
A 134 mm whiffletree (balance beam) that pivots on a press-fit 608 bearing (22.05 mm pocket, 16 mm through-bore for an 8 mm bolt or rod). It splits one pull into two equal or ratioed pulls for twin cables or tendons, cart or sled traces, or two-point lifts. Three pairs of M4 clearance holes (4.5 mm) sit at 30, 45 and 60 mm from the pivot. Using matched holes gives a 1:1 split, and mixing them gives 1.5:1, 2:1 and other ratios.
Bowden Tendon Guide Block
This guide block is part of the 'SG90 Tendon-Driven Continuum Trunk Arm' kit (print ×3). It takes a 4 mm OD PTFE Bowden tube in a horizontal 4.3 mm bore, 22 mm deep, at z = 8. The bore steps down to a 1.8 mm chamfered fairlead for the 0.8–1.0 mm braided tendon, which keeps the line aimed straight from its capstan into the tube. The block is 30 x 12 x 14 mm. Its 5 mm side ear has a 3.4 mm hole and clamps in the deck's radial slot with an M3x12 screw, a washer and a nut, so you can slide it and swivel it into line.
SG90 Tendon Capstan Drum
This capstan drum is part of the 'SG90 Tendon-Driven Continuum Trunk Arm' kit (print ×3). It keys onto the SG90's stock single-arm horn through a 7.5 x 2.5 mm underside slot and is held by an M2x10 screw that goes through a 2.4 mm hole with a Ø4.5 counterbore. A 0.8–1.0 mm braided tendon ties through a 1.8 mm cross hole in the Ø20 groove, which pulls in 31 mm of line per 180°. The drum is 12 mm tall with Ø28 flanges, and 45° chamfers on the flanges keep the line in the groove.
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.
SG90 Twin-Groove Tendon Spool
A two-groove tendon spool that screws onto an SG90/MG90S servo horn. It pulls a flexor line in one groove and lets out an extensor line in the other, so one servo drives a tendon finger both ways. It is 37 mm across and 22 mm tall, with 16 mm drums, a Ø7.5 mm bore so a screwdriver reaches the horn screw, a Ø9 mm recess for the horn hub, M2 clearance holes at radii of 12 and 15 mm on four arms, and Ø1.6 mm tie-off holes.
Print-In-Place Tendon Thumb
A two-segment robot thumb, 72 mm long, that prints in place. It has a clevis IP joint with a fused 5 mm pin running in a 6 mm bore (0.5 mm clearance) and two 2 mm flexor/extensor tendon channels that end in a tie window at the tip. The root pivots on an M3 bolt through a 3.4 mm clearance hole, so you can add a tendon-driven thumb to a servo or string-pulled robot hand.
Print-In-Place Tendon Finger
A three-segment robot finger that prints already assembled. It has two 5 mm pin knuckles with 0.5 mm clearance, plus flexor and extensor tendon channels (2 mm bores) for fishing line or Dyneema driven by a servo. It is 18 x 14 mm in section and about 104 mm long, and mounts through a 3.4 mm M3 hole at the base.
Four-Finger Palm With Thumb Clevis
The palm of the 'SG90 Tendon-Driven Robot Hand' kit. It is a 90 x 80 x 8 mm plate with a thenar lobe that bolts to the Five-Servo Forearm Deck with 4x M3x16 bolts and nuts through Ø3.4 mm holes. Four finger knuckle clevises and one side thumb clevis each take an M3x20 socket head bolt and nylock nut as the pin, with 6.6 mm gaps for the 6 mm digit tongues. Extensor grooves are cut into the underside and slotted flexor ribs sit on top at 17 mm, so the 0.5 mm nylon tendons run to each finger at their fixed heights.
Wrist Tendon Guide Comb
Upright 80 x 20 x 24 mm comb for the 'SG90 Tendon-Driven Robot Hand' kit. It bolts to the Five-Servo Forearm Deck with 2x M3x10 bolts and nuts through Ø3.4 mm holes at (112, ±20), and runs 10 tendons of 0.5–0.8 mm nylon line through Ø2.0 mm guide holes. The guide holes sit at the flexor height (17 mm) and extensor height (5 mm) for each finger lane. Each hole has a 45° countersink widening to Ø5 on the spool side, so lines that come in at an angle don't fray on a sharp printed edge.
Continuum Snake Spine Vertebra
A stackable 2-DOF vertebra for snake robots and tendon-driven continuum arms. Each 36 mm link has a 10 mm hollow centre channel for wiring and four 2.4 mm tendon holes on a 30 mm circle. You chain identical links by turning each one 90° to the last. Every pivot is an M3x8 screw that passes through a 3.4 mm clearance tab and threads into a 2.6 mm self-tap tab, and each joint tilts about ±35°. It prints without supports because a 45° funnel sits under the disc.
Print-In-Place Tendon Robot Finger
A 120 mm, three-joint robot finger that prints as one piece with 16 x 16 mm segments. The pin hinges have 0.5 mm clearance, and there are flexor and extensor tendon channels for 1.5 mm cord or fishing line, with a tie-off hole in the tip. It mounts with four M3 screws through a 32 mm wide flange, so a servo or cable spool can curl it into a gripper.