The recommended action to take is to create a spline out of the entities and then convert it into lines and arcs. 

Convert entities to splines

1. In AlphaCAM click the Geometry tab.
2. Click Splines > Create Splines
3. Select the entities to convert to a spline
4. Set the following parameters to Convert Entities to Splines.
   1. Through: Existing Geometry
   2. Tolerance: 0.01
   3. Tick Delete Original
5. Click OK (The entities will turn brown if it successfully creates a spline)
6. Click Splines > Convert Splines to Lines/Arcs
7. Set the following parameters to Convert Splines to Lines/Arcs.
   1. Tolerance: 0.01
   2. Maximum Radius for Arcs: 10000
   3. Tick Delete Original
   4. Tick Join Resulting Lines/Arcs
   5. Do not tick Preserve Layer
   6. Do not tick Set Element Z levels
8.  Select the spline > right-click on the spline (The entities will turn blue if it successfully converted to lines/arcs.)