Element to Boom Casting Pattern for Cushcraft A-3S A3S Antenna

If casting, print at 102.5% size, to allow for aluminium shrinkage!

This design is inspired by haro1d's "Element to Boom Mount for Cushcraft A-3S Antenna", split into two parts (A - boom side, B - element side) so that it could be sand cast in aluminium.

Besides splitting into two halves, I have added a slight draft angle toward the flat surface of each part and made the element-side curve better fit the elements I had (1 1/8 inch dia).

Dowel pins to align two pattern halves.

Low infill for speed of print. These are only used as patterns in sand casting - 5% infill is plenty strong enough! The patterns fit the antenna exactly - you'll need to print oversized (suggest 102.5%) to allow for Aluminium shrinkage.

Paint the print with emulsion or similar to smooth ridges in 3D print and to ease pattern release from casting sand.

George, M1GEO.