Clearance and Internal Access Review
Clearances & Internal Features for SLA and SLS
Designing 3D-printed parts with appropriate assembly gaps, internal access and post-processing requirements.
- Process
- SLA and SLS
- Materials
- Resin or powder per project
- Quantity
- State prototype quantities by design revision if samples are needed.
- Inspection
- Finished gap and accessible verification
Product Overview
Complex internal geometry may be practical to manufacture using SLA or SLS, but the intended function must still be considered.
Critical gaps, enclosed cavities and inaccessible passages can affect printing, cleaning, finishing and final inspection.
A feature that can be formed is not necessarily easy to clean or verify.
Key Features
- Take a sectional view at the location where mating components approach most closely during installation or movement.
- Identify the minimum gap and the relevant dimensional requirements.
- The available clearance should be evaluated in the specified finished condition.
- Coating, sanding or other post-processing may change the dimensions of the mating surfaces.
Manufacturing Considerations
- For hollow SLA components, identify locations where uncured resin may become trapped.
- Suitable drainage and cleaning openings may be necessary according to the geometry and process.
- The design should allow the required cleaning and post-curing operations to be completed.
- Any planned closure of access openings should be considered during design review.
- SLS parts with enclosed passages require a practical route for removing unfused powder.
- Blind branches, narrow internal openings and complex cavities can make powder removal difficult.
- Where necessary, design alternatives may include larger access openings, additional cleaning ports or splitting a component into separate sections.
- The chosen method depends on the part geometry and project requirements.
Quality Control & Inspection
- Critical internal surfaces and dimensions should have an agreed inspection or functional verification method.
- Where direct access is limited, the method must be reviewed before manufacturing.
- Flow checks, movement tests or visual inspections do not automatically establish compliance with every internal cleanliness or dimensional requirement.
Specifications to Confirm
| Minimum clearance | Identify the minimum gap in the specified finished condition. |
|---|---|
| SLA drainage access | Show the resin drain and cleaning paths. |
| SLS powder-removal access | Show powder exits and access to blind pockets. |
| Hidden-feature verification | Agree on the inspection method and any checks required before closure. |
Assembly Considerations
Closest approach
Section the assembly where parts come closest during installation or motion.
Cleaning access
Trace how cleaning reaches each relevant pocket or passage.
Inspection before closure
Define which hidden features to inspect before closing access and how to verify finished fit.
Related Products
Discuss Your 3D Printing Design
Send your CAD model with critical sections, minimum clearances and enclosed passages identified. We can review SLA or SLS process considerations, finishing requirements and available inspection options.
