Tools

Preparing the Blank cont'd.

The front of the mouth is drawn on the bottom of the plane 3/8" in front of the line drawn previously at 3" - in other words, at 2-5/8". 

Note:  Now that I'm done building it, I can see this was a mistake to make the mouth quite this wide.  Doing it again, I would simply continue the line made from the front line of the iron assembly, something closer to 1/4".

The front of the mouth is drawn at 75 degrees, and is carried to 1-1/8" above the bottom, where it intersects a 55 degree line that defines the front of the opening in the plane: