# Print-in-place: captive ball joint, Ø24 ball, limited cone

> How do you 3D print a ball-and-socket joint already assembled?

- Category: 3D printing › Print-in-place mechanisms
- Kind: Hardware
- Basis: Xem Studio design: spherical seat with 45° mouth and lip; one designed running gap of 0.40 mm
- Page: https://xemstudio.com/objects/print-in-place-ball-joint/ · JSON: https://xemstudio.com/api/geometry?object=print-in-place-ball-joint · Plain text: https://xemstudio.com/objects/print-in-place-ball-joint/sheet.txt
- License: dimension sheet CC BY 4.0 (Xem Studio); files Xem Studio Design License (free to use and sell from, not to redistribute as files: https://xemstudio.com/license/)
- Use in every chat: add https://xemstudio.com/mcp as a connector (https://xemstudio.com/use-with-ai/)

## Overall (mm)

| length | width | height |
|---|---|---|
| 60.0 | 60.0 | 45.0 |

**Exact dimensions.** True size, with no printing tolerance added.

## Notes

- 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: socket on its square flange, ball centre 14 mm up, stem vertical. The ball stands on a Ø6 flat: its lower cap below 45° is a 45° cone down to the bed.
- Support while printing: the socket is a sphere 0.40 mm larger than the ball, kept only between 30° below the equator and 45° above it — above 45° the opening begins, below 30° a 45° cone opens to the bed — so no ceiling in the socket is flatter than 45°; the ball, its foot cone, stem and knob flare are all within 45°.
- Captured: the mouth (Ø17.5) and the lower lip (Ø21.5) are both smaller than the Ø24 ball, so it can leave neither way.
- Freeing it: hold the socket, rock the stem round the full cone a few times and spin it; a firm first push breaks the foot off the bed.
- Motion: the stem tilts 29.6° from vertical in every direction (a 59.2° cone), stopped by the stem on the mouth edge, and spins freely; computed by tilting the model about X, Y and the diagonal.

## Sizes

| 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 |
| ball_d_mm | 24.0 |  |
| socket_sphere_d_mm | 24.8 | ball + 2 × 0.40 |
| stem_d_mm | 6.0 |  |
| mouth_d_mm | 17.54 | socket opening at the top (45° up the sphere) |
| lip_d_mm | 21.48 | socket's lower lip (30° below the equator): holds the ball from falling out |
| cone_half_angle_deg | 29.6 | stem tilt from vertical to the mouth stop, any direction |
| cone_angle_deg | 59.2 | full cone swept by the stem |
| spin_deg | 360 continuous | about the stem |
| axial_play_mm | 0.57 | ball lift from the drawn position |
| socket_od_mm | 44 |  |
| flange_mm | 60 × 60 × 4 | 4 × Ø4.5 on 48 × 48 |
| knob_d_mm | 16.0 | on the stem, 45° flare |
| height_mm | 45.0 | as printed |

## Where the files are

- Xem Studio: [Print-in-place mechanism design (geometry computed in the generator)](https://xemstudio.com/) — web — Xem Studio design

## Free STEP/STL (3 parts, Xem Studio Design License, Xem Studio)

Index: https://xemstudio.com/files/hardware/print-in-place-ball-joint/index.json · license: https://xemstudio.com/files/hardware/print-in-place-ball-joint/LICENSE.md

- print-in-place-ball-joint-assembly: [STEP](https://xemstudio.com/files/hardware/print-in-place-ball-joint/print-in-place-ball-joint-assembly.step) · [STL](https://xemstudio.com/files/hardware/print-in-place-ball-joint/print-in-place-ball-joint-assembly.stl) — The whole print as laid on the bed (2 bodies, already assembled); STEP keeps each moving body a separate solid
- print-in-place-ball-joint-socket: [STEP](https://xemstudio.com/files/hardware/print-in-place-ball-joint/print-in-place-ball-joint-socket.step) · [STL](https://xemstudio.com/files/hardware/print-in-place-ball-joint/print-in-place-ball-joint-socket.stl) — Socket on a 60 × 60 flange: spherical seat Ø24.8 from 30° below to 45° above the equator, 45° cones beyond
- print-in-place-ball-joint-ball: [STEP](https://xemstudio.com/files/hardware/print-in-place-ball-joint/print-in-place-ball-joint-ball.step) · [STL](https://xemstudio.com/files/hardware/print-in-place-ball-joint/print-in-place-ball-joint-ball.stl) — Ball Ø24 with a 45° foot cone, Ø6 stem, Ø16 knob

## Questions

**What limits the angle?**

The Ø6 stem meets the edge of the Ø17.5 mouth at 29.6° from vertical (45° minus the stem's half-width angle, less the gap).

**Why does the ball have a cone underneath?**

A sphere touching the bed at one point would overhang all round its bottom; below 45° its cap is replaced by a 45° cone ending in a Ø6 flat.

## Fits with

- [Print-in-place: captive wheel on a printed axle (Ø40 × 12)](https://xemstudio.com/objects/print-in-place-captive-wheel-axle/)
- [Print-in-place: barrel hinge, three knuckles, folds 180° (48.8 mm)](https://xemstudio.com/objects/print-in-place-barrel-hinge-180/)
- [Print-in-place: seven-knuckle hinge on a captive through-pin (58.4 mm)](https://xemstudio.com/objects/print-in-place-multi-knuckle-hinge/)
- [Print-in-place: captive turntable with V-ridge retention (Ø80 platter)](https://xemstudio.com/objects/print-in-place-captive-turntable/)
- [Print-in-place: linear slider on a dovetail rail with end stops (100 mm)](https://xemstudio.com/objects/print-in-place-dovetail-slider/)
- [Print-in-place: articulated chain, 6 links, 20 mm pitch](https://xemstudio.com/objects/print-in-place-articulated-chain/)
- [Print-in-place: push button with flexure return and click](https://xemstudio.com/objects/print-in-place-push-button-flexure/)