Instructions for Use (IFU) & Printing Parameters for open mode laser-based SLA systems (open-type platforms)
These Instructions for Use (IFU) and Printing Parameters define a practical engineering workflow for using 3Dresyns® photopolymer resin systems on open-mode laser-based SLA printers that allow user control of key laser parameters such as laser power, scan speed, hatch spacing and layer thickness.
This IFU applies to open-material SLA laser systems where the user can modify process parameters directly and is therefore able to calibrate exposure conditions in a structured way. It is intended for engineering, dental, medical, research and industrial users requiring controlled implementation of 3Dresyns® materials on configurable laser-SLA platforms.
1) Scope, limitations and responsibilities
Scope of application
- Applies to open-mode SLA laser printers using UV or visible curing lasers.
- Applies to workflows where the user can modify one or more of the following: laser power, scan speed, scan spacing, layer thickness, contour strategy or hatch strategy.
- Applies to 3Dresyns® photopolymer resin systems used in laser-based vat photopolymerization.
Limitations
- This document provides qualified starting logic and a structured calibration methodology, but it does not replace user-side validation.
- Different laser-SLA platforms may differ significantly in optical path, spot size, beam profile, galvo behaviour, recoating method and software implementation.
- Application-specific validation, regulatory compliance and final product qualification remain the responsibility of the user or legal manufacturer.
2) Material system and version control
3Dresyns® photopolymer resins are supplied as system-based materials that may exist in multiple formulation versions, viscosities, colours and functional configurations.
Before printing, verify that the selected resin version, lot number and associated documentation correspond to the intended printer technology and application.
Mixing versions, changing formulations or transferring parameters between materially different systems may invalidate expected performance.
Resin homogenization before printing
Resin homogeneity is part of process control. Materials should be mixed or homogenised appropriately before printing and re-homogenised as needed after storage, especially where pigments, fillers or functional additives may settle over time.
3) Record keeping (minimum)
For traceability and reproducibility, document at minimum:
- resin name, version, viscosity, colour, additives and lot number,
- printer model and laser wavelength,
- laser power at the resin surface where known,
- scan speed, scan spacing, contour strategy and hatch strategy,
- layer thickness, burn-in or base-layer strategy where applicable,
- orientation and support strategy,
- washing chemistry, time and temperature,
- drying method and time,
- post-curing wavelength, power and time,
- ambient conditions and any controlled thermal steps.
4) Why open-mode laser SLA requires structured calibration
Open-mode laser-SLA systems offer greater process freedom than closed-mode printers, but this also means the user becomes responsible for matching the resin to the laser process window.
Final curing behaviour depends not only on the resin, but also on:
- laser wavelength,
- laser power,
- spot diameter and beam profile,
- scan speed,
- scan spacing,
- number of passes,
- layer thickness,
- contour and hatch strategy,
- printing temperature and resin viscosity.
For this reason, generic exposure settings are only approximate and cannot be treated as universal recipes.
5) Practical starting parameters for open-mode laser SLA
The following values are practical starting ranges and must be validated experimentally for each resin–printer–laser combination.
- Z layer thickness: typically 25–100 µm
- Laser power: use the lowest stable range that still enables controlled curing at the selected scan speed
- Scan speed: start in the medium range of the machine and adjust according to cured depth and part quality
- Scan spacing / hatch spacing: use a moderate starting value and then tighten or relax spacing depending on inter-track fusion and dimensional control
- Contour strategy: use controlled contour exposure where edge precision is important
- Temperature: viscous resins may benefit from controlled warming, typically around 30–35 °C, where appropriate
Interpretation rule: in open laser-SLA workflows, the user should not think in terms of one fixed exposure time alone. The effective cure condition results from the combined effect of laser power + scan speed + scan spacing + spot size + layer thickness.
6) Equivalent energy logic in laser-SLA systems
In scanning laser systems, the curing result is governed by the local energy delivered to the resin. In practical terms:
- higher laser power increases cure depth,
- lower scan speed increases cure depth,
- smaller scan spacing increases overlap and effective dose,
- thicker layers require a higher effective cured depth margin.
This means different parameter combinations may produce similar cure behaviour, but not necessarily the same dimensional accuracy or surface quality.
Practical implication: a parameter set that prints successfully may still be suboptimal in terms of edge sharpness, bleeding, Z growth, brittleness or support reliability.
7) Why CRT is useful for open-mode laser SLA
The Curing Rate Table (CRT) remains the most useful starting framework for understanding resin reactivity, even in laser-SLA workflows.
Although CRT is typically measured under controlled light exposure conditions rather than by raster laser scanning, it still provides a valuable kinetic reference for understanding whether a resin is fast-curing, moderate or slow-curing, and for estimating how much cured depth margin may be needed.
In open laser-SLA systems, CRT should therefore be used together with practical scan tests rather than as a direct one-to-one substitute for final print parameters.
8) Structured calibration workflow for open laser-SLA printers
The recommended workflow is:
- Step 1 — Select the target layer thickness
- Step 2 — Select a moderate starting laser power
- Step 3 — Select a moderate starting scan speed and scan spacing
- Step 4 — Print a small flat calibration geometry
- Step 5 — Evaluate cured integrity, adhesion, edge sharpness and dimensional accuracy
- Step 6 — Adjust one key variable at a time
The user should avoid changing many parameters at once. A structured calibration sequence produces more reliable results and better traceability.
9) Practical adjustment rules
If the resin is under-cured
- increase laser power, or
- reduce scan speed, or
- reduce layer thickness, or
- reduce scan spacing slightly to improve overlap.
If the resin is over-cured
- reduce laser power, or
- increase scan speed, or
- increase scan spacing slightly, or
- reduce contour overexposure where relevant.
If the part prints but becomes too brittle
- reduce excessive curing energy,
- review contour and hatch overlap,
- review post-curing conditions.
If fine detail is lost
- reduce effective dose,
- review spot overlap,
- review contour strategy separately from hatch filling.
10) Recommended starting cure-depth logic
As a general rule, the selected process window should produce a cured depth somewhat greater than the target layer thickness.
- Fast, brittle or highly reactive resins: start closer to approximately 1.0–1.2× the target layer thickness
- Slower, softer or less brittle resins: start closer to approximately 1.3–1.5× the target layer thickness
Important note: these are approximate engineering factors, not fixed rules. Different resins may show different kinetic, mechanical, physical and adhesive behaviour.
Practical rule:
- if the part is too weak or incomplete, increase effective curing energy,
- if the part is too brittle or shows excessive bleed, reduce effective curing energy.
11) Validation using reference test files
Once a workable scan strategy has been selected, validate it using the 3Dresyns calibration files.
3Dtest1 — flat coin without supports
This geometry is used to confirm:
- basic printability,
- XY resolution,
- appropriateness of the selected scan strategy.
3Dtest2 — flat coin with supports
This geometry is used to confirm:
- supported printability,
- XYZ dimensional behaviour,
- support reliability and Z stability.
Z error (%) = (measured − theoretical) / theoretical × 100
12) Optional fine tuning
3Dresyns® resins may be further adjusted using fine-tuning additives where necessary.
- FT series may be used where additional cure speed or reactivity is required.
- LB series may be used where lower bleeding and improved dimensional control are required.
Fine tuning must be carried out gradually, with full documentation of each modification.
13) Cleaning and post-processing
Cleaning and post-processing must follow the applicable resin-family and application-specific IFUs.
Drying before final post-curing is mandatory. Washed parts must be fully dried before final post-curing.
Deviation from qualified cleaning and post-processing workflows may affect surface quality, dimensional stability, mechanical performance and long-term behaviour.
14) Basic tools and equipment
- digital caliper or micrometer,
- microscope glass slides or equivalent for small screening tests,
- precision weighing balance where additive dosing is required,
- laser power measurement tools where available,
- controlled documentation of scan strategy and post-processing conditions.
15) Governing principle
Open-mode laser-SLA printers should be treated as fully calibratable engineering systems. Final printability depends on the complete material–laser–scan strategy–post-processing workflow and must be validated by the user for the intended application.
16) Need technical support?
For printer selection, parameter definition or advanced optimisation of open laser-SLA workflows, contact info@3dresyns.com.