Materials for 3D printing planes

Choice of material is very crucial for a successful result. We tried many different materials and here’s our experience.

PLA (recommended)

Advantages:

  • Stiff (wing can handle higher Gs)
  • Low shrinking
  • Easy to print
  • Easy to glue with CA

Disadvantages:

  • Lower glass transition temperature

Standard PLA is our most commonly used and recommended material to print 3DLabPrint planes. If not specified otherwise, the planes are designed and tested with standard PLA filament. If you’re new to 3D printing RC planes, please always start with a standard PLA with a consistent diameter. At least you’ll have something to compare to while experimenting with others.

We’re using higher than usual temperature (by default 230°C) and no cooling to achieve good inter-layer adhesion. The PLA softens at temperatures higher than 50°C, that is its glass transition temperature. To achieve sufficient heatbed adhesion, we use temperature 50-60°C any higher will result in warped bottom part caused by the weight of the part.

Darker colours warp on direct sunlight as the temperature of the surface builds up fast. To avoid this, use bright, single-wavelength colours like yellow, orange, lime-green, etc…

Don’t leave printed planes in a car on hot summer days, as the temperature can easily rise above 50°C

LW-PLA (recommended)

Advantages:

  • half the weight of standard PLA
  • Low shrinking
  • Easy to print
  • Controllable foaming
  • Easy to clean and sand any imperfections
  • Easy to glue with CA
  • Less visible layers

Disadvantages:

  • Less stiff than PLA – can be controlled by extrusion multiplier and temperature
  • Lower glass transition temperature, but with lower volumetric density, less prone to warping on a Sun
  • No use of retractions on travel moves causing cosmetic imperfections

A basic FFF profile for printing LW-PLA on Prusa MK3 and compatible printers: 3dlabprint_LW_1per

This revolutionary material by ColorFabb is using active foaming technology. I.e. it’s gaining volume when being printed. The higher the temperature, the more it foams. With this feature we can use half extrusion multiplier to get the same wall width, reducing the overall weight to half. Can be used to lighten any of our planes, LW-Planes are designed to be printed from this material explicitly.

LW-planes

With extrusion multiplier and temperature we can control how stiff the resulting part will be. Leaving extrusion multiplier at 1 will result in strong walls, but the internals could pronounce to the outer shell. Normally we are using 0,5 multiplier at 230°C making the walls same thickness as standard PLA parts to reduce weight.

Since the material foams inside the nozzle, it’s oozing faster than standard PLA. Increasing retractions may cause clogs, so we decided to turn off the retractions at all. This results in hairy internal trussing, but it’s very lightweight and it’s just a cosmetic issue.

The resulting parts are less stiff, so it’s not recommended to use this material for the whole plane. It is very suitable for printing less stressed parts to reduce all-up-weight of the plane though. Tail parts, wing-tips, control surfaces, hatches, scale accessories, etc…

The material is distributed directly by ColorFabb. At first glance higher price tag is reduced by the fact, we need just a half of it compared to any other material, making it no more expensive than any other premium filament.

HT-PLA

Advantages:

  • Higher glass transition temperature compared to PLA

Disadvantages:

  • Lower inter-layer adhesion – brittle
  • Some brands require to be annealed to gain the thermal resistance
  • Usually more expensive

Printing HT-PLA requires more precise tweaking of hotend temperature. The glass transition temperature is slightly higher depending on the brand used, but this is for a price of lower inter-layer adhesion, which means more brittle planes. This often ends with broken wing mid-flight and mishaps on landing.

It can be possibly used on motor mounts that are glued to the fuselage, but it’s not always necessary.

PETG

Advantages:

  • Higher glass transition temperature compared to PLA
  • Less brittle

Disadvantages:

  • Lower tensile strength (more flexible)
  • Harder to glue
  • Harder to print – oozing
  • Higher shrinking rate

The PETG printed planes may look less brittle in the beginning, but less strong glue joints and lower tensile strength (higher flexibility) makes the planes more prone to fail mid-flight due to higher G forces. Use this material only when you know what you’re doing. Not recommended for beginners.

It is a good material to print some motor mounts, wheel discs and even springs. Always watch for good layer adhesion when printing PETG. It’s not recommended for parts that require to be glued to hold together.

ABS

Advantages:

  • Lower density – lower overall weight
  • Higher glass transition temperature

Disadvantages:

  • Hard to print
  • High shrinking rate
  • Requires an enclosure with a controlled ambient temperature
  • Possibly hazardous fumes when being printed

Printing thin-wall from ABS is very tricky. It requires enclosed printing volume with precisely controlled ambient temperature. Any draft will cause the layers to separate and warp.

Printing ABS is recommended only for skilled and well-equipped modellers with enclosed and vented printers.

Carbon fibre filled filaments

Advantages:

  • Smooth surface

Disadvantages:

  • Abrasive
  • No real advantage in strength or thermal resistance

We tested several carbon fibre-filled filaments as well. They eat the standard brass nozzles alive and there’s no advantage in any of important parameters for our purpose.