Oversize bearing bore

[bigj2]

I finish bored a customer supplied machine headstock made from a iron casting and bored a 11.5 inch diameter, 10 inches deep, precision bore oversize by .0015. In the past I have used cast iron sleeves that I pressed in and machined, I have also used electro less nickel plating. This is a large awkward part that I have to fix by boring; I do not have jig grinding capabilities so chrome is not an option. Any suggestions or recommendations?

 

[derekkarp]

I don't know if this would work in your application, but I've knurled oversize bores to get a press fit. Keep in mind the contact area is dramatically decreased, and your bore might not hold your bearing anymore. Use a straight knurl. The bad thing is cast iron doesn't knurl too well, but you can give it shot anyways. If the knurl doesn't work, you'll just have to sleeve it anyways. Hope it helps.
-Derek

 

[tripleZ]

Never tried something that big to be honest. But when we used to rebuild our OD grinder bearing race housings in house, we'd generally take the stock model, bore it about 1/4" per side oversize, grind a 1/4" walled sleeve of quality hardened tool steel for an interference fit, then freeze the sleeve and press it in. From there we would jig grind the housing to size and perpendicular to the face (you'd be boring at this point). I did this to take advantage of the hardened tool steel which was much better for wear than the old cast housing. This held up much better than chrome plating as well. Whether it would work for something like this I have no idea.