Elmer's Fancy (original scale)

[Fabrickator]

I started the "Fancy" this past weekend as my first ever engine. The column turned out perfect. I made the close fitting crank plug and when I was making the Drill Jig for the steam holes, I could not figure out what the one hole (3/16" near the crank plug) is for? I completed the jig accurately as shown but that hole kind of left me wondering if I'm missing something in his instructions.

The way I read it is you lay the edge of the jig against the 3/16" boss on the plug. Then pivoting off the 1/8" pin, drill the 1/16" exhaust hole, then flip the jig and repeat it for the intake hole. I did notice that the distance from the center lines of the crankshaft and rod pin measure up to the correct 1/4" stroke with the jig in place. So that would lead me to believe that I do use the edge of the jig to locate the ports.

Any clarification on the purpose of the 3/16" hole would be appreciated before I drill my ports. :confused

Rick

 

[Fabrickator]

The hole in question is not 3/16" as I noted, but 3/32".

 

[weez]

The 3/32" hole is used when drilling the port hole in the cylinder. The piston and rod assembly is slid into the bore, the drilling jig is placed over the pivot pin, and a 3/32" pin is put through the 3/32" hole in the jig and the hole in the end of the piston rod. This holds the drill jig on the centerline of the cylinder. Then the 1/16" hole is drilled through the jig into the cylinder.

 

[Fabrickator]

I guess I didn't read far enough ahead on the plans. Thanks!