Thanks Graham/Craig
The beginning of this thread reminds me of my own purchase; you stating being a “sucker for a nice set of castings”. I find myself with too many projects and not enough time to pursue them all.
There is no such thing as too many casting sets
Think of the enjoyment to be had fondling them dreaming of the hours of workshop fun they represent.
I felt it was important to go for that original factory look and feel for the connecting rod so it took a while to find a suitable piece of stock
The end was milled flat and a piece for the end cap cut off. The end of the bar was then remilled square. You will notice that I did not put the bolt holes in - this is because the two holes are very small and the holes constitute long holes this means that there is a good chance the drill will wander
Much easier to use the mill to accurately cut the holes in the cap and avoid any wandering. The holes can then be tapped and the cap attached bolts (and superglue just in case such little bolts try unscrewing with the vibration
).
The rod can now be set up and the little end drilled and reamed and the big end bored. I have chosen to make the big end 13.5mm this just misses the bolt holes which have been spaced at 16.4mm apart (chosen so that the corners of the bolt doesn't overhang the sides of the rod). While the rod is still in the vice the two sides can have a little taken off to taken the top end down to the 6.35mm thickness while leaving a little more on the big end to support round the crank pin.
The two sides are tapered by making two buttons to go into the two holes, then drilling and tapping two holes in a piece of scrap which had been bolted onto Tgs bed having offset one of the holes by 1.6mm to provide the required taper once clamped up
Both sides were then milled, first once side then flip it over for the other side (actually there was a bit more flipping to make sure everything is cut centrally ).
At this point I started feeling tired
and while I looked into mounting up the connecting rod for little end milling and spotted that the end of the rod was going to hit the scale
so a bit more thinking was required so I decided better of it. I did have a quick check of the con rod on the engine
Jo