Print-in-place: ratchet with flexible pawls (12 teeth, one-way) — dimension sheet
Source: Xem Studio, https://xemstudio.com/objects/print-in-place-ratchet-flexible-pawl/  (sheet CC BY 4.0; files Xem Studio Design License, https://xemstudio.com/license/)
Basis: Xem Studio design: internal ratchet teeth, compliant pawl arms, 45° V-groove bearing; one designed running gap of 0.40 mm
Catalog version: 2026-10-20

Overall (mm): length 76.0, width 76.0, height 28.0
- 3D print in place — prints already assembled, moving, in one job. Drawn at true size with no printer tolerance added; the 0.40 mm running gaps are part of the design.
- Running gap 0.40 mm per side, 0.80 mm on diameter — part of the design, drawn as is. On the 45° faces the same 0.40 mm is measured square to the face (0.57 mm along the axis).
- Bed: flat. The frame ring and the wheel both stand on the bed; in the bottom 6 mm layer the frame carries 12 internal ratchet teeth and the wheel two thin arms whose tips sit in tooth spaces, 0.40 mm clear.
- Support while printing: above the teeth the frame closes inward as a 45° cone over the arms (0.40 mm square to the arm tips' top corners) and then wraps the wheel's raised boss with a 45° V-ridge in a V-groove; the boss and knob are plain cylinders. Nothing overhangs more than 45°.
- Captured: the V-ridge in the boss's V-groove holds the wheel up and down; the boss runs in the ridge with 0.40 mm all round.
- Freeing it: hold the frame and turn the knob in the free direction one full turn (12 clicks); flex each arm once with a fingertip through the top if it feels stuck.
- Motion: free direction — continuous, the arm tips ride up the 3 mm ramps (bending 3.1 mm inward) and drop off each locking face: 12 clicks per turn. Locking direction — it turns 0.77° until a pawl tip meets a tooth face, then stops (computed).

key  value  what
gap_mm  0.4  running gap per side on every moving interface (radial, axial, under captured parts) — part of the design, not a tolerance
frame_od_mm  76.0  
teeth  12  internal ratchet teeth (radial locking face, straight ramp)
tooth_depth_mm  3.0  root Ø60, tip Ø54
pawls  2  flexible arms on the wheel, 180° apart (both engage)
pawl_arm_mm  1.6 wide × 100° of arc  on Ø51.5
pawl_flex_mm  3.06  arm-tip travel inward to pass a tooth
lock_play_deg  0.77  free turn in the locking direction before a pawl meets a tooth face
clicks_per_turn  12  free direction
knob_d_mm  43.48  wheel boss / knob
axial_play_mm  0.57  
height_mm  28.03  as printed
mount_holes  3 × Ø3.4  frame

Files elsewhere (not hosted by Xem Studio; license as stated by the publisher):
- Xem Studio: Print-in-place mechanism design (geometry computed in the generator) — web — Xem Studio design — https://xemstudio.com/

Free files (Xem Studio Design License, Xem Studio; STEP + STL, 3 parts): https://xemstudio.com/files/hardware/print-in-place-ratchet-flexible-pawl/index.json
API: https://xemstudio.com/api/geometry?object=print-in-place-ratchet-flexible-pawl