# Print-in-place: captive turntable with V-ridge retention (Ø80 platter)

> How do you 3D print a turntable (lazy Susan bearing) in one piece?

- Category: 3D printing › Print-in-place mechanisms
- Kind: Hardware
- Basis: Xem Studio design: revolved profiles; 45° V-groove / V-ridge retention; one designed running gap of 0.40 mm
- Page: https://xemstudio.com/objects/print-in-place-captive-turntable/ · JSON: https://xemstudio.com/api/geometry?object=print-in-place-captive-turntable · Plain text: https://xemstudio.com/objects/print-in-place-captive-turntable/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 |
|---|---|---|
| 100.0 | 100.0 | 10.0 |

**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: both bodies lie flat — the platter inside the base ring, both on their full bottom faces.
- Support while printing: the platter rim carries a 3 mm deep 45° V-groove; the base ring's V-ridge grows into it from the base wall, its underside at 45°. No face in either body overhangs more than 45°.
- Captured by the V: the ridge sits in the groove, so the platter can move neither up nor down out of the ring (axial retention both ways) and stays centred radially.
- Freeing it: hold the base and turn the platter one full turn each way; press it up and down once.
- Motion: continuous rotation; end play 0.57 mm each way, radial play 0.40 mm. No stops.

## 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 |
| platter_d_mm | 80.0 | turntable (platter) diameter |
| platter_h_mm | 10.0 | platter thickness |
| base_d_mm | 100.0 | base ring outside diameter |
| base_bore_d_mm | 80.8 | base ring bore |
| groove_depth_mm | 3.0 | 45° V-groove in the platter rim |
| ridge_mm | 2.43 | V-ridge of the base reaching into the groove |
| axial_play_mm | 0.57 | end play each way (0.40 square to the 45° flanks) |
| radial_play_mm | 0.4 | radial play |
| rotation_deg | 360 continuous | platter in the base |
| center_hole_d_mm | 10 | platter centre hole |
| mount_holes | 4 × Ø4.5 on Ø91 | base ring |
| platter_holes | 4 × Ø3.4 on Ø50 | platter |

## 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-captive-turntable/index.json · license: https://xemstudio.com/files/hardware/print-in-place-captive-turntable/LICENSE.md

- print-in-place-captive-turntable-assembly: [STEP](https://xemstudio.com/files/hardware/print-in-place-captive-turntable/print-in-place-captive-turntable-assembly.step) · [STL](https://xemstudio.com/files/hardware/print-in-place-captive-turntable/print-in-place-captive-turntable-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-captive-turntable-platter: [STEP](https://xemstudio.com/files/hardware/print-in-place-captive-turntable/print-in-place-captive-turntable-platter.step) · [STL](https://xemstudio.com/files/hardware/print-in-place-captive-turntable/print-in-place-captive-turntable-platter.stl) — Platter Ø80 × 10 with a 45° V-groove round its rim, Ø10 centre hole, 4 × Ø3.4
- print-in-place-captive-turntable-base: [STEP](https://xemstudio.com/files/hardware/print-in-place-captive-turntable/print-in-place-captive-turntable-base.step) · [STL](https://xemstudio.com/files/hardware/print-in-place-captive-turntable/print-in-place-captive-turntable-base.stl) — Base ring Ø100 × 10 with the 45° V-ridge, 4 × Ø4.5 mounting holes

## Questions

**What keeps the platter in the ring?**

A 45° V-ridge on the base ring inside a 3 mm V-groove in the platter rim, 0.40 mm clear on every flank: it holds the platter both up and down.

**Why a V-groove and not a flat lip?**

A flat lip would print as a flat overhang over air; both 45° flanks print without supports.

## 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: 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/)
- [Print-in-place: push button with flexure return and click](https://xemstudio.com/objects/print-in-place-push-button-flexure/)