Sorry about not responding sooner - still trying to come up with an illustration of some examples. An integrated chair leg/ chair back is an example. With the feet of the chair outside the outline of the front and the back of the chair seat, the mortises need to be angled
| | / +------+ / \ +----------+ / \
The ASCII diagram below, though the angles are too extreme, shows a rear leg part being mortised before being shaped on the bandsaw.
Mortising Chisel & Bit / / / / / / / / +--------------+-+------------+-+---------------------+ | | +-----------------------------------------------------+ chair leg chair back bottom
Make sense? Trying to convey 3-D info in 2-D when angles other than 90 degrees gets tricky.
charlie b