No experience of doing this, but for such a small amount, would lappng / sanding work? I'm thinking fine emery paper on a surface plate or similar. Would be interested to hear thoughts from the more knowledgeable.

Rob

As the crankcase halves need a central hole boring for the crankshaft bearing and about 8 holes on a PCD to hold the two halves together you would need to set the castings up for that so may as well skim the mating faces on the mill anyway and get all the holes perpendicular to the face.

Dougie, I'm assuming the protruding bearing housing and cam housings mean you can't get the castings back far enough into the 4-jaw to be able to do them in the lathe though as above you would still need to setup again on the mill for the bolt holes so may as well do it all in one sitting.

Apart from someone saying they decided about teh De Dion instead that thread is about teh Hubbard from the same supplier.

I don't recall seeing any build threads on the De Dion.