I have used my drillpress for a drum sander all the time but, not the way they show it!
I bought a set of cheap drum sanders at Ace hardware. They have a rubber insert and different grits of sleeves that fit into the chuck like a regulat drill bit.
I also use flapwheels and for smaller diameters I have a 5/15 steel rod that I put in like a drill bit and wrap sand paper around it and go at it on smaller things.
Now of course, I have my new Ridgid osculating drum sander and it is the CATS MEOW!!!
Rog