Skip to content

7-Inch Drone Arm

296 mm wheelbase, 19×19 M3 and 16×16 M3 motor pattern

An arm for 7-inch propellers in 3D woven carbon: the strength of a 2D carbon arm from a thinner, lighter part.

$154 (export price, no VAT)

Converted from the TL price at the TCMB forex selling rate (September 25, 2026).

Request a quote

  • Ships in 3–7 working days
  • Secure payment, 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.
  • With no separation between layers, the arm does not split into layers on impact, and wear on vibrating, repeated flights 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 7 in
Wheelbase 296 mm (motor to motor, diagonal)
Arm length 104 mm (outer body bolt to motor centre)
Motor pattern 19×19 M3 · 16×16 M3
Shaft clearance hole Ø8 mm
Flight-controller stack 30.5 × 30.5 mm, M3; hole 21.57 mm from centre
Body bolts 32 · 44 mm from centre, M3
Arm size 167 × 38 mm
Thickness 6.5 mm
Weight ≈ 30.5 g per arm
Material 3D woven carbon, epoxy
Grade Tg140 (VARTM)
Manufacturing CNC cut
7″ · WB 296 · 19×19 M3 / 16×16 M3 · 6,5 mm 104 167 38 X
Technical view. Dimensions in mm. Orange holes are the motor pattern; the red X arrow marks the strong direction.

Exploded assembly

Exploded assembly of the 7-inch arm set: body plates, four arms, bolts and motors

Assembly order

  1. Lay down the bottom body plate.
  2. Seat the four arms on it with their roots meeting at the centre.
  3. Pass the stack and body bolts through the arm roots.
  4. Fit the top body plate and tighten the bolts.
  5. 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
Compared with thin hobby arms, the arm is heavier: the aim is not low weight but an arm that does not break and carries load; for race builds where weight comes first, thinner arms are the better choice. Compared with a 2D carbon arm of the same strength, it is thinner and lighter.

Need a different size or hole layout?

Your own arm or frame drawing is cut from the same plate; the price appears once the DXF is uploaded.

Get a part price

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 7-inch arm is made for long-range FPV and drones carrying a light camera.

  • Long-range FPV
  • FPV with a light camera
  • FPV freestyle

Machining guide

  1. Motor screw length = 6.5 mm arm thickness + the motor’s thread depth (typically M3 × 10); the screw tip must not touch the windings.
  2. If you add holes, use a sharp carbide bit and a backing board on the exit side.
  3. 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, 167 × 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.

All questions

5 in 5-Inch Drone Arm

Cut to order · Ships in 3–7 working days

5-Inch Drone Arm

226 mm wheelbase

An arm for 5-inch propellers in 3D woven carbon: the strength of a 2D carbon arm from a thinner, lighter part.

$103 (export price, no VAT)

9 in 9-Inch Drone Arm

Cut to order · Ships in 3–7 working days

9-Inch Drone Arm

386 mm wheelbase

An arm for 9-inch propellers in 3D woven carbon: the strength of a 2D carbon arm from a thinner, lighter part.

$195 (export price, no VAT)

Sample Kit

In stock · Ships in 1–3 working days

Sample Kit

Test the material in your hands first; the kit price is credited to your first order.

$41 (export price, no VAT)