Somehow, I knew I would not offend you, I was just trying to show trex that he should not take things too literally.
On your bearing project, motorcycles avoid this problem by using a smaller diameter tube than the inside of the hub. You can slide it to one side to get a drift onto the far bearing.
I'm sure you have considered this, but you have to make sure that the spacer does not allow the bearings to be pre-loaded toward each other. The easy way around this is to let one of the bearings "float" in the hub.
Another piece of useless info. In England, al fasteners on bicycles and a lot of motorcycle fasteners used a standard "bicycle" thread. This is 26 tpi, regardless of the diameter. Could this be your axle thread? I have only seen this on the free wheel on peds.