Mastering Surface Quality: Why We Use Ironing Over Laser-Cut Plates

Mastering Surface Quality: Why We Use Ironing Over Laser-Cut Plates

When replicating armored vehicles in 1/6 scale, achieving flat, smooth surface plates is a major design challenge. To solve this, some kit manufacturers install separate laser-cut plastic panels over the printed framework.

While this technique creates a smooth surface, it introduces severe manufacturing and assembly limitations. We chose a different approach: Ironing.

The Limits of Laser-Cut Panels

Laser cutting is strictly a two-dimensional process. Cutting flat shapes from a sheet of plastic means you lose the ability to integrate critical three-dimensional details directly into the part.

• No Recesses or Guides: You cannot easily engrave depth variations, locate blind holes for rivets, or create recessed positions for hinges and detailing parts.
• Geometrical Restrictions: Intersecting armor sections – such as the true 45-degree chamfered edges where two armored plates meet on a hull – are impossible to replicate accurately with flat, square-edged laser cuts. This significantly increases assembly complexity and frustrates the modeler.

Our philosophy is that building a high-end kit should be a rewarding mechanical experience, not a chore. Therefore, we design flat armor sections as single, cohesive printed components wherever the vehicle geometry allows.

The Solution: What is Ironing?

Standard FDM top layers are inherently textured. The nozzle leaves behind parallel ridges and tiny gaps as it extrudes plastic lines, requiring heavy sanding and filling to smooth out.

To bypass this, we utilize a specialized slicing feature called Ironing.

How it works: After completing the standard top solid layer, the print head makes an extra pass over the entire surface. During this ironing pass, the nozzle extrudes only a minimal fraction of plastic (typically around 10–20%) while moving closely over the printed part. The hot brass nozzle effectively melts down the high ridges and pushes the minimal fresh plastic into the microscopic valleys.

The result is a surface that is mechanically flattened and thermal-sealed by the hot toolhead itself.

The Advantage for the Modeler

By combining 3D printing with the ironing method, we get the best of both worlds: a perfectly flat, smooth plate that still retains complex three-dimensional features, interlocking joints, and predefined alignment marks.

• Zero Sanding: These ironed components do not require mechanical sanding.
• Minimal Prep Work: A single coat of standard spray putty (filler) is enough to achieve a flawless, professional finish with minimal effort.

The Cromwell turret top armor consists of only two printed parts. Thanks to ironing, the surfaces are highly smooth while retaining all molded details and alignment features for easy assembly.
Photo shows the components after applying a single coat of spray putty.

The Trade-off

Every engineering choice has a downside. For ironing, the only disadvantage is production time.
The extra nozzle passes significantly slow down the printing process for large hull sections.

However, printing speed is not our metric of success. Our goal is to manufacture the highest quality 1/6 scale kits possible, not to churn out cheap products at maximum velocity.
We absorb the extra machine hours so you can get a superior building experience.

Explore these surface finishes firsthand across our product lineup in the Warprints Shop.