Driveshaft Adaptor

This is a post for a friend curious as to how I hooked up my new lawnmower engine to the existing drive shaft, and the related machining steps.

Step 1:

We start with a piece of iron given to me by Dad. 

I think this is a piece of steel scrap from a tandem anhydrous ammonia tank setup that failed.

Step 2:

Deck off the top for a known flat surface.  Also drill 4 holes with appropriate spacing for the existing driveshaft.

Step 3:

Bolt it down to the rotary table.

Step 4: 

Rough out the outside diameter.

Step 5:

Outside diameter finished

Step 6:

Cut a shallow relief for the backside protrusion on the existing driveshaft hub.

Step 7:

Drill and countersink the 4 holes that will connect to the hub on the new engine.

Step 8:

Here's the finished piece front and back

And this is how it all bolted together in sequence:

A:  Engine with keyed stub shaft 

B:  Install hub

C:  Install the adaptor

D:  Install the old drive shaft