> Can someone point me to a source of 6061-T6 SQUARE tubing for boom material? <http://www.metalsupermarkets.com/> They have 6061-T6 square tubing. In general <http://www.onlinemetals.com/> and <www.smallparts.com> are often handy to check. Amazon.com also has a Industrial and Scientific category. Michael Taylor, VE3TIX