magudaman wrote:.... I am also going to be machining the shaft down on the MAC to 5/8in and adding a 3/8in keyway (looks smaller currently. I'll have to look a bit closer but that bolt hole on the shaft look pretty large, and I hope 5/8in will work. .
You are probably aware that 3/4" ( 19.05mm) is an standard for industrial motor drives, which means there are lots of sprockets, hubs, clutches and adaptors etc available for that size.