Build a cradle jig out of ply (see image for a sample, bare bone design, not to scale) to hold the round stock with the jig's top as the registration platform for the DF500's fence. Depending on your design and shop set-up, it should take 30 mins to an hour to build one.
You need two lines for placement and registration. The vertical lines are marked on the jig's top. The horizontal placement lines are marked on the round leg (presumably centered with the cutter, so just one long line can be drawn). Use the milled flats (which represent the center line of the cutter) on the machine to set the fence height.