I plan on building shelving using 3/4" pipe and fittings. The general design is a 2 shelf system -180 degrees from each other around a center pole at different heights. I plan on bolting the center pole to a plywood base. Each shelf will hold between 5 and 100 lbs. I want to make sure its stable. I think as long as the base extends longer than the shelves on each side I should be ok - am I right. Attached is a basic concept.