Solid Sweep not consistant

I have just discovered the Solid Sweep function as a variant of Cut Sweep. This is supposed to simulate the action of milling cutters etc by sweeping a tool solid through a solid body.

I created a rectangular prism as the target and a simple cylinder as the tool. I then swept the tool on a straight line at an angle, so it was going sideways and down through the target. It should produce a slot with a curved bottom, but all it did was create a flat bottomed slot using the silhouette profile of the tool centreline.

I then added a fillet to the tool end, turning an end mill into a bull nose. The curved bottom of the slot duely appeared. This fillet can be minute and still work, but with a sharp edge, it fails.

Anyone seen this, any ideas?

Colin

SolidworksParts And Features