Inside Of An Elipse

In Woodsmith No. 5, you stated that the inside edge of an eliptical frame isn't really a true elipse. The method you used to determine the inside line of the frame was to use a compass set at running the pointed end around the outside line so that the pencil end scribes the inside line exactly parallel. But if the compass is twisted as it follows the elipse (which is almost impossible to prevent), the inside line won't be parallel with the elipse.

I think there may be a better way — using the "funny face" marking tool. This tool is simply a triangular piece of wood with two guide posts and a marking pin. To

mark the location for the posts and the marking pin, draw a "T" on the face of the tool, see drawing. (Be sure the two lines of the "T" are perpendicular to each other.) Then drill small holes and insert two nails with their points cut off equidistant from the downstroke of the "T".

To position the marking pin, simply mark the final width of the frame on the down stroke of the "T" (measuring from the cross-bar line), and insert a small finish nail so that only the very point of the nail penetrates through the wood.

To use the tool, the two posts are pressed against the outside edge of the frame as the tool is guided around the elipse. Then the marking pin scribes a line equidistant from the elipse.

Edwin B. Tichenor Pelahatchie, Mississippi

0 0

Post a comment