# Print-in-place: two-axis gimbal (nested rings, Ø76)

> How do you 3D print a gimbal (universal pivot) in one piece?

- Category: 3D printing › Print-in-place mechanisms
- Kind: Hardware
- Basis: Xem Studio design: concentric sphere bands, 45° cone pivots; one designed running gap of 0.40 mm
- Page: https://xemstudio.com/objects/print-in-place-two-axis-gimbal/ · JSON: https://xemstudio.com/api/geometry?object=print-in-place-two-axis-gimbal · Plain text: https://xemstudio.com/objects/print-in-place-two-axis-gimbal/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 |
|---|---|---|
| 76.0 | 76.0 | 8.0 |

**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: all three rings lie flat and concentric on the bed; the two pivot axes (X and Y) are horizontal at mid-height, 4 mm up.
- Support while printing: the facing edges are concentric sphere bands (the inner one only 13° off vertical at the bed), and each pivot is a 45° cone on a horizontal axis in a 45° cone socket; nothing overhangs more than 45°.
- Captured: each ring hangs on two opposed cones, so it cannot drop out; the sphere bands keep the 0.40 mm gap at every angle.
- Freeing it: hold the frame and turn the middle ring through a full turn, then the inner disc; the first turn breaks the bed contact.
- Motion: the middle ring turns 360° about X and the disc 360° about Y — checked in the model every 30° × 45° with no contact; together they point the disc in any direction (two-axis gimbal).

## 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 |
| outer_d_mm | 76.0 | frame ring outside diameter |
| h_mm | 8.0 | all three rings, as printed |
| ring_1_sphere_d_mm | 54.0 | middle ring outer sphere band |
| disc_sphere_d_mm | 36.0 | inner disc sphere band |
| pin_d_mm | 5.2 | 45° cone pivots, two per axis |
| center_hole_d_mm | 10 | inner disc |
| rotation_x_deg | 360 continuous | middle ring in the frame |
| rotation_y_deg | 360 continuous | inner disc in the middle ring |
| mount_holes | 4 × Ø3.4 on Ø67 | frame |

## 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 (4 parts, Xem Studio Design License, Xem Studio)

Index: https://xemstudio.com/files/hardware/print-in-place-two-axis-gimbal/index.json · license: https://xemstudio.com/files/hardware/print-in-place-two-axis-gimbal/LICENSE.md

- print-in-place-two-axis-gimbal-assembly: [STEP](https://xemstudio.com/files/hardware/print-in-place-two-axis-gimbal/print-in-place-two-axis-gimbal-assembly.step) · [STL](https://xemstudio.com/files/hardware/print-in-place-two-axis-gimbal/print-in-place-two-axis-gimbal-assembly.stl) — The whole print as laid on the bed (3 bodies, already assembled); STEP keeps each moving body a separate solid
- print-in-place-two-axis-gimbal-frame: [STEP](https://xemstudio.com/files/hardware/print-in-place-two-axis-gimbal/print-in-place-two-axis-gimbal-frame.step) · [STL](https://xemstudio.com/files/hardware/print-in-place-two-axis-gimbal/print-in-place-two-axis-gimbal-frame.stl) — Frame ring Ø76 × 8 with the X-axis cone sockets and 4 × Ø3.4
- print-in-place-two-axis-gimbal-ring: [STEP](https://xemstudio.com/files/hardware/print-in-place-two-axis-gimbal/print-in-place-two-axis-gimbal-ring.step) · [STL](https://xemstudio.com/files/hardware/print-in-place-two-axis-gimbal/print-in-place-two-axis-gimbal-ring.stl) — Middle ring: sphere bands inside and out, X-axis cones, Y-axis sockets
- print-in-place-two-axis-gimbal-disc: [STEP](https://xemstudio.com/files/hardware/print-in-place-two-axis-gimbal/print-in-place-two-axis-gimbal-disc.step) · [STL](https://xemstudio.com/files/hardware/print-in-place-two-axis-gimbal/print-in-place-two-axis-gimbal-disc.stl) — Inner disc: sphere band Ø36, Y-axis cones, Ø10 centre hole

## Questions

**Why are the ring edges spherical?**

A sphere band keeps the same 0.40 mm gap to the next ring at every tilt; flat-sided rings would jam after a few degrees.

**What are the pivots?**

45° cones Ø5.2 at the base on each ring, two per axis, running in 45° cone sockets of the next ring out.

## 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: captive ball joint, Ø24 ball, limited cone](https://xemstudio.com/objects/print-in-place-ball-joint/)