The following is a quick synopsis of Bus Driver's home made drive pulley for the cub 22 mower. The details of fabrication are general in description but I'm sure he will add more as time allows:
(quoting Bus Driver)
Questions continue about non-stock pulleys for the #22 mower. I made this using a Woods #1506 Hub and two pulleys BK40H for the 4" size. The BK40H is a Browning number, Grainger sells them. For a price much lees than the Browning, jackssmallengines.com in Maryland sells a pulley with that number, made in China, steel pulley, the Browning is cast iron. Same part number, Jack's brand of pulley is SST and seems to be well made. Jack's communicates poorly, is often very slow to ship, charges against your card quickly even if they ship slowly.
The spacer between the pulleys is 3/8" thick. The spacer must have a center hole SLIGHTLY larger than the bushing hole in the pulley.
I used four 5/16" bolts to hold the assembly together. Placement of the bolts must be done carefully as the available space really limits bolt size and placement. A lathe is amost mandatory for fabricating a quality assembly.
The Woods bushing flange is toward the tractor and that bushing must not project beyond the end of the PTO shaft. Shorter than standard bolts might be required for bushing removal. Anyone working on one of these will eventually understand my comments above. This still is not a low-cost pulley and it does take some time to fabricate.
The 4 1/2" size would use pulley #BK47H.
Great job Bus Driver!