I recently changed my perspective on mortising. I love using Paul’s technique, but I had trouble achieving a perfectly perpendicular mortise when mortising from a side view.
Even a few degrees off makes a big difference when assembling a large frame. When I had some junk on my workbench that I was too lazy to move I stood at the end of my table and started chopping a mortise. I found that I could see the angle of my mortise very easily and accurately when looking along the length of the workpiece rather than chopping from a side view. Does anyone else do this? I plan on continuing it because my eyes can see the angle of my mortise so much better.
All of my first mortise holes were angled. It was very frustrating particularly on a through mortise.
It’s really funny because I found out that standing behind it works better for me almost the same way you did.
I had used a clamp to hold the workpiece in place and the clamp was in my way. Rather than move the clamp I repositioned my body and it was like a light went off. I thought wow this is a good perspective. I have chopped most of my mortise holes that way every since. I feel sure after chopping 1000’s of mortise holes we will probably be able to chop them standing on our heads.