Print-in-place: barrel hinge, three knuckles, folds 180° (48.8 mm) — dimension sheet
Source: Xem Studio, https://xemstudio.com/objects/print-in-place-barrel-hinge-180/  (sheet CC BY 4.0; files Xem Studio Design License, https://xemstudio.com/license/)
Basis: Xem Studio design: 45° cone pivots on a horizontal axis; one designed running gap of 0.40 mm
Catalog version: 2026-10-20

Overall (mm): length 48.8, width 70.0, height 10.0
- 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: opened flat, both leaves on the bed, the barrel axis horizontal 5 mm up. Each knuckle stands on a flat foot: below 45° the barrel's round is replaced by 45° tangents down to the bed.
- Support while printing: the pivots are 45° cones on the axis (the outer knuckles' cones point into sockets in the centre knuckle), and a 45° cone on a horizontal axis never overhangs more than 45°. Leaves and barrels print as plain walls.
- Captured by the two opposed cones: the centre knuckle sits between them, so it can neither slide along the axis nor drop out.
- Freeing it: hold leaf A flat and lift leaf B slowly to 90°, back, then all the way over to 180°; repeat a few times.
- Motion: leaf B folds 181.2° up from flat — over 180°, where the leaves lie face to face 0.8 mm apart — and 98.4° the other way; the stops are leaf on leaf (computed by turning the model).

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
hinge_l_mm  48.8  length along the axis
leaf_w_mm  35.0  each leaf, from the axis
leaf_t_mm  4.6  leaf thickness
knuckle_d_mm  10.0  knuckle (barrel) diameter
axis_h_mm  5.0  axis height above the bed
knuckles  3 (12 + 24 + 12)  outer two on leaf A, centre one on leaf B
pin_d_mm  6.0  45° cone pivot, base diameter (one each end of the centre knuckle)
socket_d_mm  6.33  cone socket at the knuckle face
fold_up_deg  181.2  leaf B about the axis, from flat (drawn) to the stop
fold_down_deg  98.4  the other way, from flat
gap_folded_mm  0.8  between the leaves' faces at 180°
mount_holes  2 × Ø4.5 per leaf  

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-barrel-hinge-180/index.json
API: https://xemstudio.com/api/geometry?object=print-in-place-barrel-hinge-180