1 Model

Drop an STL, OBJ or 3MF
or click to choose · binary/ASCII STL, OBJ, 3MF · up to 300 MB

Samples:

Runs entirely in your browser: your model is never uploaded.

2 Printer

X Y Z

Margin Nozzle Min piece

Fit clearances (radial, per side, mm)

Press Glue Slip Snap Seam

Starting values for a calibrated printer. Print the joint coupon (step 5) and put your measured values here.

3 Split

Joints

Keep upright Allow tilted

4 Joints

Select a cut face in the 3D view (Cuts) or below to see its joint map.

How joints are placed

Each cut face is sliced exactly and split into contact patches, one per pair of touching parts.
A distance field (Euclidean distance transform) of each patch gives, for every point, the largest circle that fits there: its ridge is the medial axis, its maximum the largest inscribed circle, and its typical ridge value the wall thickness.
A point joint is only allowed where the field is ≥ joint radius + clearance + minimum wall, so it can never break through a visible surface or reach into a third part.
Depth is checked by ray casting into both parts (centre and 8 rim rays, also against the parts' other cut faces); pins get shorter or move if the material is too shallow.
Joints are spread by farthest-point sampling (≥ 2 per patch for anti-rotation, more on large faces).
Thin shells (walls too thin for pins) get a seam joint along the wall instead: finger joints follow the wall around ring-shaped sections; half laps and tongues are also available.
Integrated pegs and seams go on the part that does not print on that face, so the face stays flat on the bed. Horizontal holes get teardrop roofs, horizontal pegs a flat underside.

5 Build & export

Explode

Joint test coupon (< 30 min)

Two bars: pegs of the chosen diameter, sockets with six clearance steps (dimple count = step). Print with the same printer, nozzle and filament, find the loosest step that still holds, and enter it as your fit.

Peg Ø Start Step

Split anything to fit your printer.

Drop a model, pick your printer, and print-splitter finds the cuts, places joints that suit the walls it cuts through, and exports print-ready plates with an assembly sheet.

Drag to orbit · right-drag to pan · scroll to zoom · click a cut or joint to edit it