We recently ran a batch of drone exterior shells in ABS for a client we can't name. Thirty-two hours of print time. The material choice was the whole decision, and it is the one most people get wrong when they come to us for drone parts — usually because they picked the filament they already had loaded rather than the one the part needed.
Here is how we think about it, component by component, and why ABS wins for shells specifically.
Weight is the constraint everything else bends around
On a drone, every gram comes out of flight time. That makes filament density a first-order decision rather than a footnote, and the spread between common materials is bigger than people expect:
- ABS — roughly 1.04 g/cm³
- ASA — roughly 1.07 g/cm³
- Nylon — roughly 1.01–1.05 g/cm³
- PLA — roughly 1.24 g/cm³
- PETG — roughly 1.27 g/cm³
ABS is about 18% lighter than PETG for the same geometry. On a shell with real surface area, that is not a rounding error — it is the difference between a part you fly and a part you redesign. That alone rules PETG out of most airframe work, whatever its other virtues.
Why ABS for exterior shells
Weight gets ABS onto the shortlist. Three other properties keep it there.
It deforms instead of shattering. Drones land badly. ABS is ductile — under impact it bends, cracks and survives, where PLA is brittle and tends to fail catastrophically at the layer line. A shell that comes back scuffed is fine; a shell that comes back in four pieces has taken the electronics with it.
It tolerates heat. ABS has a glass transition around 105 °C against PLA's ~60 °C. A dark shell sitting in direct summer sun on a tarmac gets hotter than people think, and PLA will soften and sag at temperatures ABS does not notice.
It finishes properly. ABS can be vapour-smoothed with acetone, which melts the outer surface into a continuous skin. For an exterior shell — where layer lines are both an aerodynamic and a cosmetic problem — that is a genuine advantage no other common filament offers.
The honest caveat: ABS degrades under prolonged UV. It yellows and goes brittle with sustained sun exposure. If the aircraft lives outdoors permanently, ASA is the right call — near-identical mechanically, slightly heavier, and formulated to survive UV. We will say so at quote time rather than after the part has aged.
Material by component
Drone parts are not one problem. Matching each to what it actually has to survive:
- Exterior shells and canopies — ABS, or ASA outdoors. Light, impact-ductile, smoothable.
- Frames and arms — carbon-fibre-filled nylon or carbon-filled PETG. Stiffness per gram is what matters here, and chopped-fibre fill buys a lot of it. Note that CF-filled filaments are abrasive and need a hardened nozzle.
- Camera and gimbal mounts — nylon. It absorbs vibration rather than transmitting it into the sensor, which is the difference between usable footage and jelly.
- Antenna holders and standoffs — ABS or nylon. Small, light, and they need to flex slightly rather than snap.
- Vibration dampers and feet — TPU. Genuinely rubbery, and the only sensible choice where the part's job is to absorb energy.
- Fit-check and prototype iterations — PLA. Cheap, dimensionally stable, prints fast. Fine for checking a mount lines up before committing to the real material.
Why these print FDM, not resin
People sometimes ask whether SLA resin would give a better finish. It would, and the part would be useless. Resin is hard and brittle; a resin drone arm shatters on the first bad landing. The one place resin earns its place in a drone project is a non-structural detail part where surface finish matters more than toughness. Our FDM versus SLA breakdown covers the trade in full.
Design choices that decide whether the part survives
Material is half of it. Geometry is the other half, and a few choices do most of the work:
Orient for the impact, not for the print time. FDM parts are weakest between layers. A mounting tab printed flat will shear along a layer line under a load it would easily survive if printed on edge. Tell us how the part gets loaded and we will orient it accordingly — this is the single most common fix we make during design review.
Use walls, not infill, for stiffness. Three or four perimeters with 15–20% infill is usually stiffer and lighter than two perimeters with 50% infill. Infill mostly adds weight; shells add strength.
Design the holes for reality. FDM holes come out under-size by roughly 0.1–0.3 mm. For a motor mount or a standoff that matters — oversize the hole at design time rather than drilling afterwards and risking delamination. We cover the numbers in what ±0.2 mm really means.
Fillet the stress risers. Sharp internal corners are where cracks start. A 1–2 mm fillet costs nothing and meaningfully extends the life of an arm or a mount.
Getting drone parts made
Send an STL, STEP, 3MF or OBJ and tell us three things: what the part does, how it gets loaded, and whether the aircraft lives outdoors. That is usually enough for us to recommend a material and flag anything that will not survive the way it is currently drawn — before it prints, as part of the free design review every quote includes.
We sign NDAs as a matter of course; a good portion of the drone work that comes through the shop is confidential, including the shell batch above. Typical turnaround is 2–7 business days, with pickup in Spencerport or shipping anywhere in the continental U.S.
More detail on the service is on the drone and UAV parts page, or send a file for a free quote — we reply within one business day.