I am building a new bath cabinet that will be 61 inches long, 20 inches deep and about 35 inches tall. It will have a granite top and built of 7/8 inch thick poplar rails and stiles for the front (face frame style) and 3/4 inch maple ply for the ends and back and bottom. I want to put bun feet on it as shown here:

http://www.tablelegs.com/Bun-Feet/Co...nyBunFeet.aspx

My concern is that having a bun foot on each corner will not give adequate support for the entire length of the cabinet resulting in its sagging in the middle due to weight. If I were to put a third bun foot in the middle of the front length it would likely get in the way and people would continually kick it. Does anyone have any thoughts about how to design the supporting frame to carry the load using only four bun feet (one at each of the four cabinet corners)? In addition to a full length bottom panel of 3/4 inch ply I was thinking of installing a wide (and 7/8 inch thick) poplar web frame under the entire cab and installing the bun feet tenons through that and into the 3/4 inch ply bottom as well. Thanks for your comments.