Well, these tenons are 8″ long, 7/8″ thick and 11″ wide in oak. These are practical steps for low budget making and without table saws and crosscuts or radial arm saws. It took me 13 minutes per side which is less than 1/2 and hour per tenon. The are accurate to within a very small fraction of 1mm. They should be within 21mm and measured all surfaces within 20.79mm.
1 Set a guide to run the circular saw along
2 Run the saw to the exact depth you need. In my case 21mm.
3 Make successive cuts across face of tenon to same depth
4 Using a 1″ chisel, remove the bulk of the waste down to the depth of the saw cuts
5 Level as you go with a number 78
6 Pare down to just above the saw cut depth with a paring chisel
7 With the bevel down and so you can reach the last row, remove the last section
8 Use the number 78 rebate plane to perfect the depth in the corner
9 Clean up the whole face with smoothing plane taking care to stay to the saw-cut depth lines
10 Trim the shoulders with a shoulder plane if you have one otherwise the 78 works fine too, just make sure it’s sharp
11 My finished tenon