Project ForgeCircular arc on a part profile is being machined on a vertical CNC milling machine. CNC part program using metric units with absolute dimensions is listed below: N60 G01 X30 Y55 Z-5 F50 N70 G02 X50 Y35 R20 N80 G01 Z5 The coordinates of the centre of the circular arc are:
- A(30, 55)
- B(50, 55)
- C(50, 35)
- (30, 35)
Explanation
The arc runs from (30,55) to (50,35) with radius 20 (clockwise, G02). The midpoint of the chord is (40,45); the chord length is √(20²+20²)≈28.28, so the perpendicular offset from the midpoint to the center is √(20²-14.14²)≈14.14. This gives two candidate centers, (50,55) and (30,35); applying the clockwise (G02) sense with Z moving into the part selects (30,35) as the arc center.
Source: GATE ME 2017 Session 1 (ME-1) (2017)
This question is part of a 15-day revision cycle — sign in and Project Forge will bring it back the day before you'd forget it.