Merge STL Files in Their Original Positions
Combine 2–8 STL files locally in their existing positions. Inspect the combined preview and download one STL; overlapping shells are not boolean-unioned.
Supported input and output
Multiple ASCII/binary STLs → one binary STL; combined preview and topology statistics.
Prepare positions and units before combining files
Merge combines triangle arrays in a shared coordinate space. It neither centers each model nor converts units, so the inputs must already use compatible positions and intended scales. For example, two overlapping cubes remain two overlapping shells. Use the STL editor beforehand if an individual source needs to move.
How to use this tool
- Select or drop 2–8 STL files together.
- Inspect their combined placement; correct individual files elsewhere if necessary.
- Run Merge meshes and download the combined STL, then check it in your destination application.
Limitations to check
- This combines triangle geometry; it is not a boolean union. Intersecting or overlapping solids remain intersecting or overlapping.
- Files are never individually centered or rescaled. All sources must already use the same intended coordinate units. STL cannot verify those units.
- Per-source visibility and repositioning are not included; use the transform editor before merging if placement needs adjustment.
File and processing limits
- 2–8 STL files; 8 MiB per file, 16 MiB total.
- Combined geometry: 150,000 stored vertices and 50,000 triangles; output up to 3 MiB.
- 20 seconds per job, including reading and topology checks.
Processing happens in this browser; your file and filename are not uploaded. Cancel, reset or replace the file to stop its worker. Downloads are generated locally.
Questions about this workflow
Why are overlapping parts still intersecting?
Combining triangles is not a boolean union. Creating one intersection-free solid requires an explicit boolean operation in a suitable modeling tool.