Each printer model, and even different units of the same printer model*, have different powers across the printing area (the vat/resin tank) available for curing the resins, with differences of around 300% or higher**.

This document published by the FDA: Technical Considerations for Additive Manufactured Medical Devices clearly highlights that:

Optimal settings and parameters for a single model of a machine can vary greatly when printing different devices or components. Furthermore, optimal settings and parameters can vary between machines of the same model even when printing the same devices or components.

See below the evidence and proof of facts: the power of two commercial MLCD printers, the Phrozen Sonic Mini with 0.6 mW/cm2 vs the Anycubic Mono X with 1.7 mW/cm2.

This huge difference in power among different printers of even the same technology significantly affect the printing settings: the exposure times for printing the resins, where even differences of exposure times of 5-10 seconds per layer or more can be required for printing the same 3D resin.

Too low power printers leave too high concentrations of unreacted monomers and extractables, resulting in decreased safety and biocompatibility. Not all printers meet the quality requirements for printing biocompatible resin systems by SLA, DLP, LCD and Inkjet printing technologies.

Most printers suffer from certain significant variability of their specifications, such as their light power which naturally decays upon time as well as their power variability across the resin tank which affect significantly the safety and biocompatibility of any 3D printed medical device, since the polymer conversion, the % of monomer conversion to polymer, and the % of extractables depend on the quality, specifications, and reliability of the printer, such as its light power, wavelength, light power distribution across the printing area, light power decay prevention system, etc, and the implemented printing and postprocessing protocol specifications.

Learn about the natural decay of light power of 3D printers:

Examples of power** difference of different LCD & MLCD printers, which 

  • Examples of several standard multicolor LCD printers:
    • Anycubic Photon Zero 0.27/0.30 mW/cm2*
    • Longer Orange 30 0.29/0.31 mW/cm2
    • Anycubic Photon S 0.43/0.46 mW/cm2
  • Examples of several monochrome LCD "MLCD" printers:
    • Phrozen Sonic Mini 4K: 0.60/0.70 mW/cm2
    • Phrozen Sonic Mighty 4K: 0.79/0.93 mW/cm2
    • Phrozen XL Mono 4K: 1.05/1.30 mW/cm2*
    • Creality LD-002H: 1.40/1.80 mW/cm2
    • Anycubic Photon Mono X: 1.70/1.90 mW/cm2
*Note: Examples of power differences of two new units of the same MLCD printer model:
    • Commercial mono 4K printer unit 1: 1.05/1.15 mW/cm2
    • Commercial mono 4K printer unit 2: 1.10/1.30 mW/cm2

**Note: power in mW per cm2 across the vat expressed with two values: low value in the corner/high value in the centre of the resin tank to show the power variability across the printing area