Summary

Useful to aid taking a bearing using a Silva Baseplate compass and other similar models with a baseplate of 4mm x 60mm; Based on original design by TDX00

Post-Printing

I created the vertical line on the mirror by placing the mirror into the space with the reflected surface facing into the print and carefully marking a line on the backing of the mirror with a sharpie - ensuring this lined up with the makings on the upper edge of the print and the centre of the sighting window. Then removed the mirror and scored this line with a sharp knife. Glued the mirror the correct way round.

How I Designed This

This is a remix of the genius design by TDX00.
The modifications I have taken were to add notches to help lining up the object being sighted as lining the sighting window at the same angle as the baseplate. Also, to reduce parallax error I have (1) made the insertion point thicker thus reducing lateral movement and (2) placed a mark on the upper edge to facilitate a vertical line to be drawn on the mirror. This line should appear to go through the centre of the reflected image of the bezel as well as the object in the plane of the notches in the sighting window.

Silva Expedition Sighting Aid