We gave up long ago trying to force fit those nice precision bearings on non-precision shafting. We now bite the bullet and order precision shafting (slightly undersized) from McMaster-Carr (see "Keyed Shafting"). The more force you apply in assembling these two parts, the greater the odds that you will have to dis-assemble these two parts at the worst possible time.
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A lathe, some emery cloth, and time ................