Overview
If your printed appliances are not fitting properly, the issue is often related to optical cleanliness, workflow adherence, or dimensional compensation. This guide walks through the most common causes and how to resolve them.
Clean the Optical Path
Light travels through the printer’s optical path before reaching the resin. Any dust, smudges, or fingerprints along this path can interfere with light projection and affect dimensional accuracy.
The optical path includes two primary components:
- The printer glass
- The resin tank
Ensure both components are clean and free of debris.
Refer to the Pro: Cleaning the Optical Path Guide
After cleaning the optical path, run a new print to determine whether the issue persists.
Review Workflow and Design
Review the workflow guide for the specific appliance you are printing, along with the Instructions for Use (IFU) and Workflow Guide for the resin being used. Confirm that all recommended steps for printing, washing, and post-curing are being followed.
Pay special attention to:
- Recommended orientation
- Layer thickness
- Resin selection
- Post-processing requirements
If you designed the appliance yourself, verify that the design parameters are suitable for 3D printing. Thin walls, sharp transitions, or unsupported geometries can lead to dimensional inaccuracies.
For consistent, validated results, consider using SprintRay Cloud Design.
Use Appliance Fit Offset
Appliance Fit Offset allows you to increase or decrease the outer dimensions of a model by applying a uniform offset. This tool can be found in Print Setup.

Important details:
- Fit adjustments modify the X and Y dimensions only.
- Z-axis dimensions remain unchanged.
- The impact of the adjustment depends on the appliance type.
For example:
- A positive offset increases external dimensions but decreases internal clearances, such as the inner diameter of a hole.
- A negative offset decreases external dimensions but increases internal clearances.
Apply small adjustments incrementally and test fit before making larger changes.

If the issue continues after completing these steps, contact SprintRay Support for further assistance.