ADDITIVE MANUFACTURING & INDUSTRIAL 3D PRINTING

SLS / MJF 3D Printing Powder Escape Hole & Wall Sizing Calculator

Calculate minimum powder evacuation escape hole diameters (D_escape), hollow wall thickness, thermal shrinkage factor (S%), and living hinge geometry for HP MJF and EOS SLS.

1. Input Parameters

Printing Process & Material

Internal Hollow Cavity Volume (V) [cm³]

Total enclosed internal volume requiring depowdering.

Hollow Shell Wall Thickness (t) [mm]

Recommended: 1.2 mm - 2.5 mm for structural integrity.

Planned Number of Escape Holes

2. Calculation Results

Min. Escape Diameter (D)

0.0 mm

Thermal Shrinkage (S%)

0.0%

Est. Trapped Powder Mass

0.0 g

Min. Wall Safety

3. Geometric Visualizer

Tooling & Vector Prepress Engineering Notes

1. The Two-Hole Flow Principle: Single escape holes frequently clog during bead-blasting and vacuum depowdering due to powder compaction. Providing two opposed holes allows pressurized air in one side and cake ejection from the other.

2. Dynamic Diameter Scaling: For cavity volumes $V \le 20\text{ cm}^3$, minimum hole diameter is $3.5\text{ mm}$. For larger cavities, scale hole diameter via $D = \max(4.0, 1.8 \cdot \sqrt[3]{V / N_{\text{holes}}})$.

3. 2D Cross-Sectional Vector Slices: In direct 2D layer slicing (SLI, CLI, SVG), internal hollow islands must maintain strict outer-to-inner boundary parity to prevent slicer inverted solid fills.