Printed drone parts: arms, guards and mounts

On a drone everything is judged by two numbers: what it weighs and what it holds. Nearly every design decision trades between them, and 3D printing is good at that game because you can change where the material goes without changing supplier.

What prints well

• Prop guards. The standout application: in TPU they take the hit, spare the propeller and spare whatever they touch.
• Camera, GPS, antenna and receiver mounts. Small bespoke parts, impossible to buy exactly as you need them.
• Landing gear and legs. In TPU they survive hard landings without passing the shock into the board.
• Canopies, covers and fairings: they protect the electronics and are pure bespoke geometry.
• TPU camera dampers and isolators, to keep motor vibration out of the picture.
• Bench and workshop parts: calibration stands, transport cradles, assembly jigs.

The arms: the honest conversation

The arms on a racing drone are made from laminated carbon fibre, not printed, for a reason worth understanding: laminated fibre has continuous strands running end to end, and that continuity is where the stiffness and strength come from. Printed carbon fibre PLA has fibres a fraction of a millimetre long, scattered at random. The name matches; the material does not.

That does not mean an arm cannot be printed: for a small, slow, gently flown or bench-test drone, it works. It means knowing what you are doing, oversizing it, and accepting it is a prototype part. And it means that if the drone flies over people, over traffic or at speed, a printed arm is not the right part.

The enemy nobody plans for: the sun

It is the most frequent failure and the most avoidable. A black drone sitting on the ground on a summer day in Barcelona passes 55 °C easily, and at that temperature a PLA part softens standing still. People discover the problem when the camera mount has sagged in the boot, not in flight. Anything that will sit in the sun is PETG at minimum, and ABS if it also picks up heat from the electronics.

Losing weight without losing strength

1. 1Take material from the middle, not the walls. A part’s stiffness lives in its outer surface; the infill in the centre barely contributes and does weigh.
2. 2Three perimeters at 15% infill weighs less and holds more than two perimeters at 40%.
3. 3Hollow it in CAD before touching the infill. A part designed hollow always beats a solid one at low infill.
4. 4Fillet everything you can. Radii spread the stress and let you remove material everywhere else.
5. 5Do not drop the layer height chasing strength: it does not give any. It gives finish, and multiplies time and price.