Why we never use PLA for our 1/6 scale kits

Why we never use PLA for our 1/6 scale kits

In the 3D printing community, PLA (Polylactic Acid) is the most common and easiest material to print. However, for professional 1/6 scale RC models, it is completely unsuitable.
We do not use PLA for any components in our kits.

Here is the technical reasoning behind this decision.

1. Thermal failure in outdoor environments

The primary limitation of PLA is its low glass transition temperature (around 50-60°C). At this point, the plastic begins to soften and deform under its own weight.

We learned this the hard way. Our very first prototype model was irreversibly warped and ruined on a standard summer day just by being exposed to direct sunlight.

• High-quality automotive primers, paints, and UV-protective clear coats offer zero thermal insulation; they cannot prevent the underlying PLA from absorbing heat and deforming.
• RC models operate outdoors, often sitting on hot asphalt or dirt. PLA cannot survive these real-world conditions.

Thermal deformation of PLA printed part after sun exposure:

2. Brittleness and long-term degradation

While PLA is rigid and has high tensile strength, it lacks impact resistance.
Under mechanical stress – such as the vibrations and impacts experienced by a 1/6 scale heavy RC tank – PLA cracks rather than flexes.

Furthermore, we have serious concerns regarding its physical properties over time.
PLA is biodegradable under specific industrial conditions, but even in standard environments, it degrades, becomes increasingly brittle, and loses structural integrity over the years.

3. Post-processing limitations

Our manufacturing workflow involves mechanical power sanding to achieve flat, seamless surfaces on large hull and fuselage sections.

Because of PLA’s low melting point, friction from power tools immediately melts the plastic instead of cleanly shaving it away. The material clogs the sandpaper and ruins the part’s geometry, making efficient industrial post-processing impossible.

Material Policy

We replaced PLA entirely with high-temperature, impact-resistant polymers like modified PETG, ABS, and advanced carbon-fiber composites.

We apply these strict material standards to all products found in our 3D printed kits. We prefer to pay more for engineering-grade materials rather than deliver a model that fails during its first summer outdoor operation.