Your drawing is pretty simple.
For the sake of using fairly rounded numbers lets say that:
- the main shape has a radius of 92.5 @ 150,105
- the notches have a diameter of 6 an lay on an radius of 98.5
- the top notch is rotated 2.4° from straight up
- the left notch is spaced 90°
- the right notch is spaced 104°
- the roundings need to be with r=5
See attached file: test plate_Construct.dxf
On layer 1... I drew the construction lines.
Remark that I drew the spokes straight up and then copy-rotated them 2.4°
On layer 2... I drew the circles.
Thaw layer 2...
The double construction spokes help me with opening the circles.
For the sake of visualising this I made a copy of the circles on 3...
Freeze layer 2... and thaw layer 3...
The circles are openend with 'Break out Segment' (D2) with option Remove Segment active.
Hide the construction lines:
Freeze layer 1...
Activate 'Round' (RN) with option Trim active, radius 5.
Visualized on 4...(a copy of 3...)
Freeze layer 3... and thaw layer 4...
The places you point at matters for the preview and the result.
I already did 3 roundings of the 6.
Finaly you end up with 12 loose entities. (12 Arcs in this case)
Freeze layer 4... and thaw layer 5...
It is a good practice to convert them to a single closed contour.
'Select All' (TA) >> 'Polyline from Selection' (OC).
Select the created Poly, visual check if its simplex and complete.
Check if the closed nature in the Specific Properties is indeed 'Yes'.
If not the error would be where the poly ends.
Even if your CAM doesn't support polys it serves to use OC to check.
The explosion of a proper contour as poly is also flawless as single entities.
Regards,
CVH