Hi @JvanReij
There are many ways in which it is possible to reverse engineer a part. The most appropriate will almost certainly depend upon the part you are working with.
The key to successful reverse engineering is to view the mesh as your guide, not your master. For example, if you measure the radius of an arc as 4.90567 is it likely that the original designer used that value? Probably not. Much more likely he or she designed it to be 5mm. The idea is to get the part as close as possible to what the original designer had in mind. Try to look at the part from the original designer's point of view. If you were designing the part from scratch, with nothing to go on, how would you model it? A few minutes spent looking at the part, and trying to work out how you would design it, is time very well spent.
If I understand correctly, you want to end up with a solid model that you can edit easily. If the parts are reasonably prismatic (made up of boxes, spheres, cones etc.) this should be fairly easy with PowerShape alone. Using the various primitive commands, create the basic building blocks of the shape, and then use Boolean commands to add or subtract material to create the finished shape. Wherever possible, use commands such as 'fillet' and 'hole' only once you have the basic shape defined. This makes the final model much more robust.
For more complex shapes (but ones that are still prismatic) I typically begin by cutting sections through the mesh. These can then be 'perfected' (often completely re-drawn) to create a parametric sketch (with dimensions and named parameters) that can be used to create extruded or revolved shapes. Changing the dimensions of the sketch will update the solid and re-run the history.
If, for some reason, it is not possible, or not feasible, to create a full parametric solid model, there are still lots of ways in which you can change 'dumb' solids in PowerShape, using an array of Direct Modelling tools.
Jon Hunwick
