Mach III offers a variety of catalog models for shaft-to-shaft coupling.  Those catalog models provide shaft attachment with a keyway and set screw. 

For this application, the customer wanted to attach the coupling half to the shaft using a keyless frictional locking device.  Mach III outfitted a catalog model through shaft pilot mount clutch, C5A2R-STH, with a custom designed coupling. 

Keyless Frictional Locking Device

Would a custom design make your assembly process easier? Mach III has custom adapters and couplings options for many catalog models.