A recess is a cavity milled in the plane of the part along a set contour (for a built-in handle, lock, hinge, niche). The form is opened from the part's operations menu with the «Recess» button; next to it is a «?» button with this help. This article covers the side, shape and sizes; see separate articles for position, depth and edge (links at the end).
Side
A recess is set on the plane of the part — on the front or back side. A recess is not made on the edge.
Recess type
The «Type» field sets the contour shape:
- Rectangle — straight corners;
- Rounded rectangle — a rectangle with rounded corners (the rounding radius is set separately);
- Circle — a round recess (set by radius, the length and width become equal to the diameter).
Length and width
The recess sizes are set in the «Recess length» and «Recess width» fields. They can be entered as a number or a formula — the computed value in millimetres is shown nearby. For the «Circle» type the length and width are not editable: they are automatically set equal to the diameter (double the radius).
Radius
The «Radius» field is available for a rounded rectangle and a circle (for a plain rectangle it is disabled). The allowed values depend on the production's milling tool diameter and on the smaller side of the recess:
- Rounded rectangle — radius from «tool diameter + 1» to half the smaller side;
- Circle — radius from «half the tool diameter + 2» to «smaller side − 2».
The radius is set with no more than two decimal places — otherwise the field highlights an error. For a circle, changing the radius automatically recalculates the length and width into the diameter.
Calculated area
Next to the recess size fields, its calculated area in m² is shown — you can see what the machining is charged for without opening a separate report.
What is next
The other recess parameters are in separate articles:
- Reference point and coordinates of a recess — where to place the recess on the part;
- Recess depth: blind and through;
- Edge and edge processing inside a through recess.
How the cutter enters a pocket
The lead-in is built for the cutter that was actually chosen, not in a generic way.
- Normally the cutter enters along an arc.
- On a thin board — 12 mm — a shallow straight lead-in is built instead of the arc: the plunge point sits one cutter diameter into the pocket and five diameters along the edge. The slope comes out at roughly 1:5.
- The straight lead-in is used only if it fits: five diameters plus half a diameter of clearance along the edge, and one diameter plus the same clearance into the pocket. If it does not fit, the arc stays as before.
- In a pocket with rounded corners the free length is measured to the start of the rounding, not to the corner itself.
The half-diameter clearance is the cutter radius: without it the cutter would cross the pocket wall or the rounding at the plunge point.