Repairing and Hollowing Models

Hollowing parts is fairly common in resin printing, as it reduces large cross sectional areas (better print success) and minimizes resin use. NexaX Pro users have access to the Repair Tool to fix minor mesh issues, and the Hollow Tool to hollow parts without having to go back to their CAD software.

NexaX Pro also offers the Perforation Tool, which can add drain holes to the part. Drain holes are important in both hollowed parts and parts with cup-like geometries to avoid surface defects or cupping blowouts. See our Designing for LSPc article for more details on cupping.

To use these tools, click the Edit menu on the left side tool bar. There are three options within the menu: Repair Selected Models, Hollow Selected Model and Perforation Tool.

Repair Selected Model

NexaX can do simple repairs if the imported model has mesh problems. The software will attempt to resolve any non-manifold mesh problems such as holes, flipped polygons and zero-thickness walls.

To perform auto-repair, select the model by clicking on it and choosing the Edit Menu > Repair Selected Model. It may take a while to repair the model depending on how many issues there are with the mesh.

Sometimes severe mesh problems may not be repairable by the software alone and need to be resolved in the original CAD software in order to address the errors properly.

Hollow Selected Model

The hollow and lattice tools can turn a solid model into a shell of a defined thickness with an optional lattice structure inside. 

Wall Thickness - Allows adjustments to the wall thickness of the part (in mm). Thicker walls are needed for printing without a lattice.

Add Lattice - Generates the lattice with the following parameters:

• Lattice Beam Thickness - The thickness of the branches of the lattice. 

• Inner Cell Size - The lattice is made up of an array of individual cell units. The smaller the cell size, the denser the lattice.

Edit Drainage Holes - In most cases, hollowing a part will create a cupping effect. This tool can automatically create a drain hole at the bottom of the part to avoid cupping. However, the perforation tool allows for more freedom with drainage hole placement.

Perforation Tool

Shown above is a half-view of a part (for visualization - actual part shown on bottom left) that would exhibit cupping. The tapered overlay is where the tool would create the hole.

The Perforation Tool generates a hole (straight or tapered) through a part. This is most commonly used to create drain holes for parts that would encounter cupping. Hole Radius defines the radius for the hole, the top slider being for the outer radius and the bottom slider being for the inner radius. 

Keep Subtracted Parts will generate parts for the subtracted area that you can print and later use to plug the hole during post-processing. A tapered hole is recommended to make aligning the subtracted part easier. 

Updated October 07, 2022 18:31