Nashbar came out with a new headset press that does 1-1/2" headsets, and so their old 1-1/8" headset presses are on sale for $50. Plus at this time you get an additional 10% off, so $46. Plus shipping of course.
I swear I don't work for Nashbar. I'm just trying to make all of them go away because I am too broke to buy one, and the temptation is killing me.
Or you could just do the threaded rod or long bolt and washers and nuts trick.
Yeah, I'm all about the homemade $3 version. If you had trouble keeping it aligned, throw another washer in that's the same outer diameter as the inner diameter of the cup. This will keep it centered on the rod.