Automatic Support Generation Addon

Theoretical Background of Support Systems in VAT Photopolymerization

In VAT photopolymerization (SLA, DLP, and LCD/MSLA printing), support structures are not merely temporary scaffolding to overhangs; they are mechanical anchors that counteract significant physical forces. Understanding these forces is crucial for optimizing support parameters in ChiTuBox.

Peeling Forces (Сили на отлепване)

The primary challenge in VAT printing is the peel force. When a layer is cured, it adheres to both the build plate (or the previous layer) and the bottom of the resin vat (typically a flexible FEP, nFEP, or PFA film). As the build plate lifts to allow fresh resin to flow underneath, the cured layer must be peeled away from the vat film. This lifting action exerts high tensile stress on the printed part and its supports.

• Film Flexing: As the vat film is flexible, it stretches before releasing the print. This creates a peeling front that moves from the edges to the center of the cured area.
• Support Failure: If the total cross-sectional area of the contact points of your supports is too small, or their shear strength is insufficient, the print will tear off the supports, leaving only the cured base on the build plate and the model stuck to the FEP film (often referred to as a "pancake").

      [ Build Plate ]
       |    |    |
       v    v    v (Lift Force)
     [ Support Pillars ]
       |    |    |
     [ Cured Layer ]  <-- Peel Force (Tension)
    =================
    [   Vat Film    ] <-- Flexing/Stretching
    -----------------

Suction Cup Effects (Ефект на вендузата)

When printing hollow models or models with concave geometries facing the vat bottom, a closed volume is formed. When the Z-axis lifts, resin cannot easily escape, and a vacuum is created inside this cavity.

Auto-Support Parameter Configurations in ChiTuBox

ChiTuBox classifies support structures into three default profiles: Light (Леки), Medium (Средни), and Heavy (Тежки). Each profile uses different dimensions for the three main sections of a support: Top, Middle, and Bottom, along with the Raft.

Comparison of Default Support Profiles

Below is a reference table outlining the typical configurations for the three profiles: