I next made a supporting frame with 1/4 hole for the bracket to engage. This frame supports the block upright to be sanded such that the center of the pivot is 5 1/2" (half the 11" diameter) from the face of the block. The block is then attached with 2-sided tape and the fence is adjusted such that the block is well supported by the edge of the table. (I don't trust the 2-sided tape that much!)
I just barely touch the face of the block to the sanding disk as to take off small increments at a time. I feed the block into the sanding disk against the motion of the disk; remove the block support and block from the hinge pin; bring it to the back; reassemble and repeat.See photo.