7 in 
Cut to order · Ships in 3–7 working days
7-Inch Drone Arm
296 mm wheelbase
An arm for 7-inch propellers in 3D woven carbon: the strength of a 2D carbon arm from a thinner, lighter part.
Price on request
Request a quote
9-Inch Drone Arm
386 mm wheelbase, 19×19 M3 and 16×16 M3 motor pattern
An arm for 9-inch propellers in 3D woven carbon: the strength of a 2D carbon arm from a thinner, lighter part.
Price on request
The price is quoted according to quantity and delivery terms.
Request a quote
No payment is taken on the site; the proforma invoice is sent by email.
- Ships in 3–7 working days
- E-invoice, NDA on request
Our products are made with OWC. What is OWC?
Highlights
- Vibration and impact energy are damped in the 3D woven structure: less vibration reaches the flight controller, PID tuning is cleaner and flight is steadier.
- Because fibre running through the thickness binds the layers, the arm does not split into layers on impact; on vibrating, repeated flights, wear is lower than in 2D carbon arms.
- Motor pattern 19×19 M3 and 16×16 M3; fixed to the body with the 30.5 × 30.5 stack bolts and two body bolts.
Compatibility
Values are per arm. The body hole layout is in the table; check it against your own frame.
| Property | Value |
|---|---|
| Propeller class | 9 in |
| Wheelbase | 386 mm (motor to motor, diagonal) |
| Arm length | 145 mm (outer body bolt to motor centre) |
| Motor pattern | 19×19 M3 · 16×16 M3 |
| Shaft clearance hole | Ø10 mm |
| Flight-controller stack | 30.5 × 30.5 mm, M3; hole 21.57 mm from centre |
| Body bolts | 34 · 48 mm from centre, M3 |
| Arm size | 212 × 38 mm |
| Thickness | 6.5 mm |
| Weight | ≈ 40 g per arm |
| Material | 3D woven carbon, epoxy |
| Grade | Tg140 (VARTM) |
| Manufacturing | CNC cut |
Exploded assembly
Assembly order
- Lay down the bottom body plate.
- Seat the four arms on it with their roots meeting at the centre.
- Pass the stack and body bolts through the arm roots.
- Fit the top body plate and tighten the bolts.
- Mount the motors on the pattern at the arm tips.
Body plates, bolts and motors are not included; they appear in the image to show the assembly. A matching body plate is not part of the catalogue.
Design notes
- Strong direction
- The arm is cut along the plate’s strong direction: the X axis, where most of the fibre runs, follows the length of the arm. The red X arrow in the technical view marks it.
- Centre lock
- The roots of the four arms meet at the frame centre and form a solid square; clamped between the body plates, an arm cannot rotate.
- Weight
- The arm is heavier than thin hobby arms; its design gives priority to resistance to breakage and to load carrying. For race builds where weight comes first, thin arms are more suitable. Compared with a 2D carbon arm of the same strength, however, the arm is thinner and lighter.
Different size and hole layout
Your own arm or frame drawing is cut from the same plate; the price is quoted from the drawing.
Mechanical values
| Property | Value |
|---|---|
| Tensile strength | 813–993 MPa |
| Flexural modulus | 94–107 GPa |
| Glass transition temperature (Tg) | 140 °C |
Ranges are test results on 3D woven RTM specimens. Verify them under your own load conditions before using them as design values.
Applications
The 9-inch arm is made for long-range drones and drones carrying a mid-weight camera.
- Long range
- Cinelifters and camera carrying
- Industrial inspection and mapping
Related articles
Machining guide
- Motor screw length = 6.5 mm arm thickness + the motor’s thread depth (typically M3 × 10); the screw tip must not touch the windings.
- If you add holes, use a sharp carbide bit and a backing board on the exit side.
- Use the pair of holes where the arm leaves the body, and the arm’s slots, for cable ties.
Full guide: Carbon plate CNC cutting guide
In the box
- 4 × arm, 212 × 38 × 6.5 mm
- Protective packaging
Frequently asked questions
Will the arm fit my frame?
The arm root sits at the frame centre; the hole at 21.57 mm matches a 30.5 × 30.5 flight-controller stack and the two outer holes take the body bolts. The dimensions are in the Compatibility table; check them against your own frame before ordering. If you need a different hole layout, your drawing can be cut through the CNC cutting service.
Can I buy a single arm?
Arms are sold only as a set of 4; all four are cut from the same plate with the same fibre direction.
How does the arm affect PID tuning?
The 3D woven structure damps motor and propeller vibration, so less vibration noise reaches the flight controller’s gyro. Filter and PID tuning is therefore cleaner and flight is steadier. Tuning values depend on the motors, propellers and frame, and should be checked on every build.
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10 in 
Cut to order · Ships in 3–7 working days
10-Inch Drone Arm
420 mm wheelbase
An arm for 10-inch propellers in 3D woven carbon: the strength of a 2D carbon arm from a thinner, lighter part.
Price on request
Request a quote
In stock · Ships in 1–3 working days
3D Woven Structural Carbon Plate
A structural carbon plate whose layers do not separate, thanks to fibre woven through the thickness.
$600 (export price, no VAT)