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Arc/Tanto,C,C,R

Arc Tangent to Two Circles

Creates an arc tangent to two existing circles with a specified radius.

What It Does

The Arc/Tanto,C,C,R operator creates an arc of specified radius simultaneously tangent to two existing circles. The arc blends smoothly between the two circles.

Syntax

Arc/Tanto, C1, C2, R, XLarge|XSmall|YLarge|YSmall, IN|OUT

Quick Input

C: [first circle] C2: [second circle] R: [radius] Dir: ○ XL ○ XS ● YL ○ YS Tan: ● OUT ○ IN

Direction Selector

SelectorMeaning
OUTArc externally tangent to both circles
INArc internally tangent to one or both

Worked Examples

C0=centre(0,0) r=20, C1=centre(80,0) r=20, R=30 Arc/Tanto, C0, C1, R=30, YLarge, OUT → A0: arc tangent to both circles, upper solution Tangent to C0 at start, tangent to C1 at end

Analytic Rule

Arc centre at distance R+r_C1 from C1 and R+r_C2 from C2. Solve circle-circle intersection for arc centre. Arc sweeps from tangent point on C1 to tangent point on C2. Result: Exact analytic arc.

FAQ

When would I use this?

Creating a smooth blend arc between two circular features in a CNC profile.

What is the minimum radius?

Depends on circle sizes and positions. XyzPilot returns an error if R is too small.