ModelSplitter has entered public beta, splitting large or awkward STL and 3MF models into printable parts directly in a browser. Users draw planar or surface-following cuts; the software adds pins and sockets, numbers parts and exports them.

Its most important claim concerns data handling: models remain on the user's computer rather than being uploaded. The beta may send anonymous counts about tools, approximate model size, run time and failures, but the operator says it does not send files, names or typed data. Feedback text and mailing-list email are transmitted only after their respective buttons are used.

Cutting for printability

Beyond planes, users can draw curved seams on a surface, hiding a joint in a contour or fold. Painted regions and automatic cuts are additional modes. Parts can receive pin-and-socket joints or loose keys printed separately; position, length and tilt can be adjusted.

The disclosed automatic planner seeks fewer parts under printer-size constraints. On a life-size Walker model it proposed 58 pieces versus 112 from a simple grid. This developer example is not a general promise to halve part count; results depend on build volume, geometry and allowed orientations.

Assembly guide and identification

Exported pieces can be numbered and the system produces an illustrated PDF assembly guide. That may reduce confusion between files and physical parts. It does not specify adhesive, surface preparation, bond gap or load sequence, which remain material- and application-specific decisions.

The developer printed a keyed 20 cm model on a Bambu A1. One demonstration shows the workflow can be completed, not a universal tolerance. Fit depends on XY and Z error, material, shrinkage, hole orientation, slicer compensation and finishing.

What to inspect before printing

After splitting, check each part for watertight mesh, normals, wall thickness and sufficient material around keys. A socket can break through a thin shell; a curved cut can form a sharp edge or difficult overhang. Number engraving can be too shallow or weaken a small part.

Export one joint as a coupon and print it with the intended profile. Measure clearance, pull-out force and fit after primer or paint. In a loaded part, treat the joint as a stress concentrator, not only a locator; a larger bond, fastener or other mechanical connection may be needed.

Beta and business model

Current tools are free in public beta. A Kickstarter is planned for late November; early Pro pricing is listed at £25 and later pricing at £49 as one-time payments. Free/Pro allocation may change before version 1, and lifetime access is conditional on the service continuing.

Local execution helps confidential geometry, but companies still need to review code version, licence terms, offline behaviour and update control. A beta is not a qualified CAD or production-preparation system.

Editorial conclusion

ModelSplitter addresses a defined problem by combining part division with joining and assembly documentation. Its value is not the cut alone but the link between local processing, surface-following seams, keys and a part guide. Physical fit and structural suitability still require validation for every machine-material-profile combination.