Here is a sub routine to do the circle method. Code is by Henrik.
(;-) TP
#1000 = 75 (Diameter)
#1001 = 4 (Degrees per cut)
#1010 = #1001
#1020 = [90 / #1001]
G17
M98 P1234 L#1020 (Call subroutine)
M30
O1234
#1002 = [0-90-#1010]
#1003 = [COS[#1002] * #1000 / 2] (Calculate radius)
#1004 = [SIN[#1002] * #1000 / 2] (Calculate Z height)
G1 X[0-#1003] Y0 Z[0-#1004] F250 (Position, remove '0-' to do internal)
G2 X[0-#1003] Y0 I#1003 F500 (Do Arc)
#1010 = [#1010 + #1001] (Increment counter)
M99
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