Here the first cut is done on the chair leg, I marked the profile edge with a black marker, if you cut into it you will have to start over again with a jig, so be careful. It is a good idea to also mark on your leg post which side is the top of the leg, it is easy to get confused when you take it out and put it back for the next cut.
Here you can see the second cut, the leg was turned 90 degrees for this cut, move the jig from the left to the right while you are cutting, it takes quite a few passes before it is done. I am using a 1/8" thick cutter and the pin is the same diameter, there is a tiny space between the cutter and the pin, they are not touching and shouldn't. You basically cut until the pin glides smoothly against your jig profile. Of course a normal drill press moves up and down so you have to find a way to keep it locked on the height that you want.
Here you can see the leg after the first two cuts.
Now we need to move the leg to the other side of the jig for the last two cuts, to cut the back profile of the knee. you can see one of the flat sides are facing you.
The cut finished.
Turn the leg again 90 degrees for the last cut, your last flat side on the wood will face you.
Next I put the leg in a lathe to turn the feet, you can do this by hand too, I only turned it flat, the curve from the bottom will be done by hand.
The cutting on all four legs are finished, now there still is a lot of hand finishing left to do, at the moment they are square, but we want them nice and round.