a 1/2" cutter is weaker and will leave cusps along the floor
Tools to use:-
Roughing----Ø1.5" cutter with R0.25" corner Bullmill to rough the slot
( once up the middle, then along the walls ) XY offset=0.010", Z offset=0.010"
Finishing----Ø1.0" cutter with R0.25" corner bullmill to finish the floors, stay away from the walls. Multipasses ON, XY offset=0.020" Z offset=0.0"
Ø1.0" cutter with R0.25" corner bullmill to finish the walls. Multipasses OFF, XY offset=0.0" Z offset=0.0"
to get wireframe- Xform translate the chained shape using "Join" to Z-6"
to get surfaces - draft the chains in the Z- direction for 6"
to get a solid - extrude the chained shape you have, make the arrow point in the Z- direction, and accept, set distace to 6", and accept
Your WCS and toolplanes should be "Front view"
and the geometry you select for a 2D_Contour will be the top "join" wireframe lines you created.
All up you should only have 3 - 4 operations in total for the slot