# Frame arm thickness

> How thick should FPV frame arms be?

- Category: Drone design › Drone frame layouts
- Kind: Standard part
- Basis: Design rules and figures from the cited sources; example geometry by Xem Studio
- Page: https://xemstudio.com/objects/arm-thickness/ · JSON: https://xemstudio.com/api/geometry?object=arm-thickness · Plain text: https://xemstudio.com/objects/arm-thickness/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/)

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

## Notes

- Thicker arms resist crashes and push resonance higher but add weight (UAVModel).
- 5 mm is standard for 5 in freestyle; 6 mm adds 15-20 g and moves resonance to 240-280 Hz. Arms narrower than 12 mm at the motor can flex into a 40-60 Hz wobble (UAVModel).
- The file is a reference example built by Xem Studio from the numbers above (Reference 5-inch build: 220 mm diagonal within Grepow's 210-250 mm class for 5 in props.). Sizes the sources do not fix are illustrative; scale the example to your own vehicle.

## Sizes

| parameter | value or range | source |
|---|---|---|
| 4 mm | 3 in / ultralight 5 in | UAVModel |
| 5 mm | 5 in freestyle/racing; ~180-220 Hz | UAVModel |
| 6 mm | +15-20 g; ~240-280 Hz | UAVModel |
| 8 mm | 7 in long range | UAVModel |
| Arm width at motor, 5 in | 13-14 mm | UAVModel |

## Where the files are

- UAVModel blog: [FPV Frame Geometry: Deadcat vs True X vs Squashed X (2026 guide)](https://blog.uavmodel.com/fpv-frame-geometry-deadcat-vs-true-x-vs-squashed-x-prop-view-resonance-and-flight-feel-2026-guide/) — web — Publisher's page; dimensions are facts
- UAVModel blog: [FPV Drone Frame Selection Guide: Geometry, Materials, and Arm Design](https://blog.uavmodel.com/fpv-drone-frame-selection-guide/) — web — Publisher's page; dimensions are facts

## Free STEP/STL (1 parts, Xem Studio Design License, Xem Studio)

Index: https://xemstudio.com/files/hardware/arm-thickness/index.json · license: https://xemstudio.com/files/hardware/arm-thickness/LICENSE.md

- arm-thickness-layout: [STEP](https://xemstudio.com/files/hardware/arm-thickness/arm-thickness-layout.step) · [STL](https://xemstudio.com/files/hardware/arm-thickness/arm-thickness-layout.stl) — true x frame layout: 220 mm motor-to-motor diagonal, 5 in props (discs show the swept area; arms and plate illustrative)

## Questions

**Why do arms wobble?**

Below 12 mm wide they flex under torque (UAVModel).

## Fits with

- [True X quad frame](https://xemstudio.com/objects/true-x-frame/)
- [Stretched X frame](https://xemstudio.com/objects/stretched-x-frame/)
- [Squashed (wide) X frame](https://xemstudio.com/objects/squashed-x-frame/)
- [Hybrid X frame](https://xemstudio.com/objects/hybrid-x-frame/)
- [Deadcat frame](https://xemstudio.com/objects/deadcat-frame/)
- [H frame](https://xemstudio.com/objects/h-frame/)