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stereolithography process & SLA models - explanation & help

The stereolithography process is one of the most widely used rapid prototyping techniques for making plastic SLA models & begins with STL files created from a 3D cad design. The supports required for overhangs & cavities are automatically made by stereolithography process software.stereolithography process - schematic view


The support & SLA model files are cut into thin horizontal slices & sent to a machine which performs the stereolithography process using a computer controlled laser to draw the bottom layer onto the surface of a liquid polymer that hardens in the places hit by the laser.


This is lowered to the depth of the next layer which is drawn directly on top of the previous one. This is repeated until the SLA model & stereolithography process are finished. Supports are removed manually once SLA models have been taken from the machine . The slicing method used by the stereolithography process causes visible layers on SLA models - these are removed by sand blasting.

More free help with stereolithography process - notes & examples of SLA models

When considering using the stereolithography process please bear in mind the following :-

  1. The accuracy, ± 0.1 - 0.2% & layer thickness, 0.125 - 0.2 mm are both dependent on how fast you need SLA models
  2. SLA models created by the stereolithography process are sensitive to UV light
  3. Several, including flexible resins are available - specify if you need SLA models for aesthetics & part evaluation or durability & robustness. Various finishing grades are available, plus painting & texturing e.g. rough spark/high gloss
  4. The stereolithography process is suitable for creating SLA models with good surfaces and fine detailing which can be used to check 3D Cad models & for limited functional testing e.g. testing the 'fit' in your assembly.  For functional models with snap fits, living hinges etc use SLS models
  5. SLA models can also be used to make Polyurethane moulds and 10 - 20 models vacuum cast from them in resins close to the final moulding material & colour. UL94V0 fire retardant models are also available.
stereolithography process - model of security case

Security case SLA models
finished & painted

SLA model - waxing pot

Waxing jug SLA model
finished & painted

stereolithography model of children's cup

Childrens cup SLA model
finished only