boring for crankshaft

[brickyParticipant @bricky]

The shaft has three cranks and is supported in bearings.The crankcase has two 7mm cross walls to support the mid bearings.Before milling out the waste ,I would like advice on wether to drill and bore from the solid or after milling the pockets between the walls. If there is enough height on my SX3 I will do it on the mill if not I will line bore on the lathe.

[Peter Cook 6Participant @petercook6]

I have never done this – so am no expert. However I would have thought that milling out the waste would stand a significant chance of distorting the cross walls sufficiently to obviate the accuracy of line boring. I would probably rough drill in solid to minimise any distortion of the walls, mill out the pockets then finish line bore the bearings.

But someone will be along shortly to  give you a proper answer!

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