G-Code Help: Radius to Radius Tangent Points (in X,Y)

[robertemond]

G-Code Toolpath: __oOo___ = Here’s a rudimentary depiction of a line (G01), a .195r radius fillet (G03), .313r larger radius (G02), and another .195r radius fillet (G03) connecting tangent to the line (G01) for G-Coding inside of a pocket at .500" z-depth and I’m using a 3/8 end mill. This is the only part I couldn't figure out nor find math websites to calculate the chords.

The center of the .313r lays on the same line that the .195r fillets share their tangent points with.

Direction: From left to right (G41) climb mill

PATH: The tool path follows the line (G01), follows the smaller .195r counterclockwise (G03) starting at the tangent point with the line

The .313r shares a point of tangency with the .195r; the toolpath then runs clockwise (G02) until meeting the second .195r to once again share a tangent point returning to the last tangent point with the line (G01).

Need help calculating the (x,y) points of tangency in order to G-code aluminum.

Thanks in advance,

Robert

[the_gentlegiant]

Here you go... Fanuc based but usable on most.

You know... this is what CAD/CAM is for. Get some!


Comp arc lead in and lead out.

1/4" LINE LENGTH EACH SIDE

Adjust depth, feed and speed to suit.

(USING I-J)

%
O500(0.195/0.313 CONNECTED ARCS)

(PROGRAM ZERO IS 0.313 ARC CENTER)

(Z ZERO IS TOP OF PART)

(START D4 AT 0.1875)

T4M6 (3/8 4FL END MILL)
G17G20G40G49G54G80G90G98

G0X-0.958Y0.105
G43Z0.1H4S4500M3T5
M8
G1Z-0.175F75.
G1G41Y0.005D4F68.
G3X-0.758Y-0.195I0.2J0.
G1X-0.508
G3X-0.313Y0.I0.J0.195
G2X0.313I0.313J0.
G3X0.508Y-0.195I0.195J0.
G1X0.758
G3X0.958Y0.005I0.J0.2
G1G40Y0.105
G0Z0.1
M9
G53Z0.Y0.M5
M30
%

**************************************************
(USING R)

%
O500(0.195/0.313 CONNECTED ARCS)

(PROGRAM ZERO IS 0.313 ARC CENTER)

(Z ZERO IS TOP OF PART)

(START D4 AT 0.1875)

T4M6 (3/8 4FL END MILL)
G17G20G40G49G54G80G90G98

G0X-0.958Y0.105
G43Z0.1H4S4500M3T5
M8
G1Z-0.175F75.
G1G41Y0.005D4F68.
G3X-0.758Y-0.195R0.2
G1X-0.508
G3X-0.313Y0.R0.195
G2X0.313R0.313
G3X0.508Y-0.195R0.195
G1X0.758
G3X0.958Y0.005R0.2
G1G40Y0.105
G0Z0.1
M9
G53Z0.Y0.M5
M30
%