I'm in the same boat, I own an atlas mill and have one arbor also . I bought a piece of 4140 16" x 2" . Ill be doing some turning on my logan , taper to morse number2 , then about 10" of arbor turned to 1 1/4" . The second will be 7/8" plus about ten spacers to fit , ill buy some thin ones to do gang mill . The one reason I bought it is to cut gears for my big drill press . The table and head lifts both need gears , ill make up a half dozen and sell a few to pay for the rest. Original gear from Rockwell is over $400.00 one gear . I'll eBay them for $100 free ship . Seems I remember seeing a #9 on eBay arbors for sale .