3D model surface finishing

Finish the accessible upper surface

Surface uses the evaluated solid selected in Model setup. The cutter stays parallel to the setup's Z axis. Camera orbit changes your view; Cutter Z changes the machining orientation.

The first strategy supports bodies with an accessible top above a flat underside. Curved tops, slopes and upper ledges can be followed. A model with an overhang or a downward-facing surface above its lowest point is blocked, including a non-flat underside in the current orientation. Change the setup direction or use a suitable model.

Paths are clipped to the projected body footprint, or to the selected faces when using Selected faces. Through openings split the lanes into separate paths. A cutter that cannot enter a narrow recess remains above the surrounding material, so such detail may remain unfinished. Other bodies, clamps and fixtures are not included in this operation's target or clearance calculation.

Choose the faces to machine

1. In CAM → 3D Model, choose Surface → Selected faces.
2. Click an upward-facing flat or curved surface. Amber shading and an outline show the selection. Click more faces to add them; click a selected face again to remove it. No modifier key is needed. Clear selection removes all picks.
3. Orbit or use Top to inspect the area, then choose Add model surface. The button is disabled until at least one supported face is selected.
4. To change an existing operation, open its Operations card and choose Edit machining area. Change the picks or switch to Whole body, then choose Apply machining area. This updates that operation and preserves its cutter and cutting settings.

The selected faces define a cutter-centre boundary in the machining XY plane. The cutter radius can overlap its edges; selection does not promise that all neighbouring stock remains untouched. Separate selected areas stay separate, and openings are excluded. The contact height and complete ball-nose sweep are still checked against the whole setup body, including neighbouring faces that are not selected. A nearby raised feature may lift the cutter and leave more material on the selected face.

Vertical walls and undersides cannot be selected in the current Cutter Z direction. Smoothly connected curved mesh strips are picked as one patch; sharp seams separate patches. Existing projects keep their Whole body target until you explicitly change it. Face selection does not remove the strategy's accessibility or finishing-stock requirements.

Direction and stepover with allowance

Along X runs each lane in setup X and steps in Y. Along Y runs in Y and steps in X. Stepover is the percentage of cutter diameter between lanes, from 5% to 90%. A smaller stepover gives closer passes and generally smaller scallops, with more motion and processing time.

Allowance is a positive offset around the model, from 0 to 10 mm. Zero follows the evaluated surface; 0.5 mm leaves at least that nominal clearance around it. The ball radius is included in the contact calculation, so the programmed tool tip differs from the surface height on slopes. A small 0.005 mm vertical guard protects the sampled moves and output rounding; it is not a guarantee of overall CAD or machining accuracy.

Each straight cutting segment is checked against the evaluated model triangles. Where a straight connection would intersect the protected surface, its endpoints are raised. This can leave additional material near abrupt details. The complete cutter must stay within the configured stock's XY boundary, and Safe Z must be above every compensated point.

Connections → Surface follow makes short turns between nearby raster lanes at the cutting feed. The turn follows the compensated surface and may change Z. Its complete ball-nose sweep is checked against the model and allowance, including the rounded output coordinates. The centreline must remain in the chosen machining area. With Selected faces, connected turns cannot cut across an unselected gap. Through openings, distant lanes, large height changes, sharp details that cannot be cleared, and exhausted linking work limits retain a Safe-Z transfer. These turns are additional finishing cuts; they do not rely on a claim that the stock is already cleared.

New model Surface operations default to Surface follow. Existing projects retain their Safe-Z transfers until you choose the new mode. Connections → Safe Z lifts after every lane. Connected turns and Safe-Z transfers show the result; the transfer count excludes the initial approach and final retract, which are always retained. Connections are saved with the operation and support Undo/Redo.

Feed, Plunge and Spindle use the existing CAM controls. There is one finishing pass with many lanes. Unconnected lanes retract to Safe Z, transfer in XY, and approach vertically at the plunge feed. There are no incremental roughing depths or surface-entry ramps in this strategy. Surface-following turns still require stock roughed close to the model; this is not cutting-load or remaining-stock verification.

Inspect the target and the actual removal

3D Model shows the target body with its finishing paths. Simulate → Toolpaths also shows the approach, cut and retract moves. Material uses the rounded ball-nose profile to show the stock removed by those moves. It begins with the configured rectangular stock; it does not infer a previously roughed shape or verify cutting load.

A surface pass alone leaves the surrounding stock and may leave steep walls or fine details unfinished. Start with model roughing where suitable, then Surface, and the appropriate model pockets before the outside contour. Complete-job Material playback accumulates removal across these operations. A new model surface is inserted before the first outside contour; review the complete job order and remaining stock.

Preview and G-code use the same motion plan, with stock-top Z0 and the selected work origin. Connected turns appear as Link during playback and use explicit XYZ G1 feed moves in the program, not rapids at cutting depth. The program identifies the connection strategy, model finishing and the need for pre-roughed stock. Review the export preflight, tool reach and remaining material before machining.

Compare the finishing result

Use Simulate → Remaining stock to compare After roughing with After finishing. A thickness colour scale makes remaining terraces and excess above the target easier to see. The comparison includes earlier enabled operations and uses a bounded overview grid. Read Remaining stock for the interpretation and limits.

Regenerate after model or setup changes

The operation remains linked to its setup body. Editing the evaluated solid, stock, placement, machining orientation or work origin invalidates the saved generation stamp. Output and model simulation are blocked until Regenerate model surface succeeds. Review the new paths and lowest tip Z after regeneration.

A deleted or different setup body cannot silently replace the reference. Restore the original setup or create a new surface operation for the intended body. Cutter, direction, stepover and allowance edits recalculate paths directly. Setup and operation edits support Undo/Redo and project save/open.

Selected face references are saved with the operation. Setup rotation and placement retain those references, but still require regeneration. If an edit changes, splits or removes a selected face, regeneration blocks and asks you to pick the faces again through Edit machining area. Changes to the evaluated mesh can also require reselection. Cadivari does not silently replace a missing selection with Whole body. Switching to Whole body is an explicit choice.

Current limits

• One setup body and one fixed cutter direction. Choose Whole body or up to 128 accessible flat or curved faces; custom sketch boundaries are not included.
• Ball-nose finishing of pre-roughed stock. Layered model roughing is available as a separate operation; rest machining and automatic cutting-load checks are not included. Roughing terraces may leave more material than its nominal allowance.
• No undercut machining, tool tilt or holder/fixture collision model. Check the physical setup with the CAM safety checklist.
• Paths follow the evaluated triangle mesh and use linear moves. Fine geometric detail and steep regions need visual inspection; this is not an exact analytic surface or a guaranteed scallop-height finish.
• Complexity limits stop excessive meshes, dense rasters or expensive contact calculations. Simplify the model, increase stepover or choose another cutter if generation is blocked. Cached paths and an idle renderer keep ordinary model navigation responsive.
• The existing Fretboard Designer surface workflow remains available separately.