Area 51% wrote:All I need to know is how did you get the rectangular hole up the middle of the handle? .
I've been wondering that too. Immediately started thinking "how would I do that". First thing that came to mind was a two piece design with a routed rectangular slot, then glue the two pieces together.
Another option, commonly used to put square tanged files into a wood handle, is to burn it in. Drill a round hole into the handle, then take a similar sized piece of steel, heat it red hot, and burn it into the hole. I often use this method when I make tools.
Bob Dz...
Sonex B, Tri-gear
(technically within walking distance of Sonex)
N624DZ (reserved)
Plans exist to eliminate confusion, not create it.