Pump/ motor shaft coupling

Getting ready to build up a power unit After rummaging around finding a 3 hp motor with the valve block still attached after pluging it in to see if it ran I started searching through my pumps I found several so disassembled a couple to see which one might be good both were. I search and search and could not find the correct shaft coupling for the motor to the pump I had selected. Then I remembered the reason why so many of these units fail was due to the couplings.
So I took some measurements
Attachment 30685
then drew it up
Attachment 30686
Then to find a hard enough piece of stock to make the coupling out of the closest thing I could come up with to be near hard enough was a 7/8" grade 8 bolt
Attachment 30687
After turning it down
Attachment 30688
I milled the ends to fit the pump on 1 end and the motor on the other then thought one things these coupling do is the can wobble of center since nothing held them true except for the slits and tang being 90° to each other
on 1 end I recessed the slot by counter boring the coupling just a little and for the other end I found that PVC nonconductive flex conduit was just about .2
020" undersize in bore I pressed it over the coupling and the motor shaft the pump end has the recess so both ends are now held centered
Attachment 30689
Assembled and ready for a tank to mount it in
Attachment 30690