I have a not quite cylindrical tube - it's effectively a bit squashed. From this I have to cut a hole. Effectively it's a square wrapped around the outside of the tube. It wraps around an angle of nearly 90 degrees. The edges of the hole need to be perpendicular to the surface. If the tube were made of wood, the hole would be cut with a router such that the cutter is always at right angles to the surface.

I can project a shape onto the surface (modifying the shape until the hole outline is correct) but there seems no easy way to cut it at right angles to the surface as the inner projection is akin to a straight extrusion.

Any suggestions as to how to do this? If the shapes of the tube and the whole were geometrically easy I could do this by applying some simple maths to make a vaguely pyramidic shaped cutter to subtract from the cylinder but they aren't.

I'm using Shark Fx 9 btw.

Thanks Tim. Once I had worked out that the imprint option is achieved by holding down the Option/Alt button this worked great. There seems to be a bug in that you can offset a face through the back of the item (maybe it's a feature ;) ) if you set the offset distance greater than the thickness of the object that you are cutting a hole through. But it, like the other imprint faces can easily be cleaned up.

I was about to try creating a surface with the cut-outs already in place and then using the offset surface and draft surface commands to make up all the surfaces of the object prior to stitching together but this solution seems a tad easier since I can project the desired shape.


Roland