Dress-up: Dogbone¶

In one sentence: Add corner relief over-cuts at inside corners so that square-cornered parts can fit into pockets milled with a round end mill.

Overview¶

Workbench: CAM
Menu: CAM → Dress-up → Dogbone
Command: CAM_DressupDogbone
Shortcut: none

Adds dogbone (or T-bone) corner reliefs at inside corners of a pocket or profile path. A full-radius end mill cannot cut a true right-angle inside corner — it leaves a fillet of material equal to the tool radius. A dogbone relief over-cuts a small circle at each corner so that a square-cornered part (e.g. a dovetail, tenon, or sliding fit) can seat fully.

Intuition¶

When an end mill reaches an inside corner, it must round the corner to its own radius. If a square-cornered mating part must fit into that pocket, it will bind on these radii. A dogbone drill moves the tool slightly past the corner, cutting a small circular relief — the "bone" of the dog shape — that provides clearance for the square corner.

When to use it¶

Pocket or profile operations where a square-cornered part must fit.
Joinery (dovetails, box joints, mortise and tenon) routed on a CNC.
Any operation where corner radii would prevent assembly.

When NOT to use it¶

On outside corners — dogbone reliefs are only meaningful at inside corners.
When the mating part has radiused corners that match the tool radius.

Dogbone styles¶

Style	Description
Dogbone	Circular over-cut tangent to both wall faces
T-bone	T-shaped slot along one wall face
Horizontal	Extension perpendicular to the X-axis
Vertical	Extension perpendicular to the Y-axis

Key parameters¶

Parameter	Description
Incision	Relief cut size as a percentage of tool diameter
Custom	Fixed extra distance instead of percentage
Side	Which corners get relief: left, right, or both

Common mistakes and pitfalls¶

Dogbone applied to Pocket — corners still not clean

The Dogbone dress-up works on the path output, not the geometry. For a Pocket operation, the relief is only added to the final finishing pass. For a rough pocket interior, apply a Profile finish pass around the pocket perimeter and add Dogbone to that Profile.