I agree with both Jonathan and Jazz

how ever cut3d is quite a crap program

I am doing a trial in MDF of the 3D model as I'm typing this reply

for my model I have chosen 10mm cut depth it did suggest 18mm on the scale but I chose 10 mm as I'm not after a deep cut
The model is 400x350x10mm.

I could chose to cut a silhouette cut out in cut3d but it left a big piece of material in the shape of a island near a shoulder so I've gone for a square cut out (in cut3d) you can't chose to cut a oval or round shame

I am doing a roughing pass with a 6mm single flute cutter and in cut3d this only allows you one cutter for this operation

so I'm in the roughing pass part of the program and after that the finishing pass program and then the cut out and then the preview the roughing pass has three passes at 3 mm and then one at 0.50 and then the finishing pass (two) at 45 degrees to the rough cuts

and then I have chosen to do a cut out but I will stop it at 11 mm

cut3d is quite limited as the only tools you have is the ones with in the set stages and that's it.

The CNC machine is cutting on pass three and is at a depth of 9 mm the finishing cutter is only a 6 mm ball as that's the smallest ball cutter I have a the moment

and as I said it's only a MDF test, I'm waiting for my Oak timber to arrive so I can glue it up plane it and start making the coffee table

I plan to have the model carved into the legs as well (on two different plains) but we will see how a test goes first

James