1. Used two metal parallel arms of the same length. This makes possible a wider range of size variations since the router tray can be moved along a longer distance in relation to the template. Furthermore, lifting the router is easier when moving the stylus to a new position.
The earlier version of this router pantograph is found here:
2. One problem noted in the original set up is the tendency for the stylus to twist and spring when the router bit encounters resistance. Wider metal rails solved that problem.
3. I thought of a more secure method of holding the workpiece. The work piece is locked in place with the use of printers quoins between two boards which are held down with clamps.
The maximum useful distance between the boards is 9 inches. Maximum effective workpiece height is 8 inches when locked using the quoins.
4. The master letters or template are position in a transparent folder taped and clamped to the table.
Upon the suggestion of my contact Armand, I tried using hardwood. Splinter were still present, however, after some sanding, it looked better than my first trials on ordinary plywood. I plan to try out design variations later and possibly the 3D effect.
-- Ed "Real happiness is one that you share."