[Matt Reiland]

Originally Posted by Rod

The bars are 3/8" solid stainless steel. My thought is that are more likely to spring than to bend.

Wow, that is an incredible amount of weight to be putting into the base!! 3 rows of solid steel bar plus what looks to be large blocks of aluminum to hold them? Add in the weight of about 12ft of chain and you should be at about 75 lbs.
Have you considered aluminum tube maybe 1/8" wall 1" dia?

All the 1/4" in the base is a little heavy for a first robot, you could build the whole thing out of 80/20 and still be a bunch lighter. Just my 2 cents but I have yet to see a robot that has that much weight to burn unless you plan on having no manipulator.?

It does look nice and clean in inventor, great job on that.