A Marking and Cutting Gauge
This design is taken from a Woodjoy Tools gauge I have admired. I guess imitation is a sincere form of flattery. I made all the parts with the exception of the VERITAS knob. The blade is an ex-spade bit, V-edged so that it can cut in either direction. The construction is brass, Tasmanian Blackwood (top) and Jarrah (below). The fence is reversible to mark curved edges. The face is 3".
The knife is secured by a brass machine screw from the front end of the arm. You can just see this in one of the pictures below. The other end of the screw is filed flat. Further, the knife is also held within a mortise so that there can be no sideways movement. Incidentally, since the picture was taken I have lowered the angle of the V so that there is a greater slicing action from the blade. The higher angle tends to tear a little.
I shaped the brass end, cut and fitted it to the arm flush to the end of the mortise, then removed this to cut the mortise for the knife. After a dry fit I epoxied the brass end, pinned it with brass rod (1/3 of the way in from each side - not all the way through), and drilled and tapped the thread for the knife holding screw.
The other feature is the tenon that keeps the fence square to the sliding arm. This can just be seen at the rear of the knob.
Regards from Perth