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

thingiverse

**If printing, scale up by 102.5% to account for aluminum shrinkage!** This design takes inspiration from harold's "Element to Boom Mount for Cushcraft A-3S Antenna," breaking it down into two sections (A - boom side, B - element side) so that it can be sand cast in aluminum. In addition to splitting the design into two halves, I've added a slight draft angle towards each part's flat surface and adjusted the curve of the element-side section to fit my existing elements perfectly (1 1/8 inch diameter). Dowel pins help align the two pattern halves securely together. Low infill is used for rapid printing, as these patterns are only intended for sand casting - a 5% infill is more than sufficient. The printed parts will fit your antenna exactly; to account for aluminum shrinkage, print them oversized (try scaling up by 102.5%). After printing, apply emulsion or a similar coating to smooth out ridges and make it easier to release the pattern from casting sand. -George, M1GEO