edge finish - ripples and ridges

[dsc]

Simply curious if it's possible to skim it or not, but I guess it's just not worth it at this point.

Another question I've got is slightly out of topic for this thread, but I'll go ahead and ask anyway. I have a bearing housing which seems to be the correct diameter if measured across x axis, but 0.1mm smaller when measured across y axis. What would cause such an error? runout on a lathe? it simply seems elliptical rather than round.

Regards,
dsc.

[Jonathan]

That's a clear example of trying to cut faster than the machine, or tool, is good for. The wavy lines could also be caused by severe resonance ... either way a finishing pass would have sorted it out.

I could skim the parts for you, but it's not a quick job unless they're quite small.

I have a bearing housing which seems to be the correct diameter if measured across x axis, but 0.1mm smaller when measured across y axis. What would cause such an error? runout on a lathe? it simply seems elliptical rather than round.

Backlash, or more precisely - greater backlash in one axis. Bearing housings should really be bored, not milled, since even if you have a rigid machine with zero backlash the pocket will end up something other than a circle. The bore doesn't have to be out by much for you to either just have a loose fit, or worse distort the outer ring of the bearing causing it to wear prematurely. If I'm cutting a part on the CNC Router which includes a bearing, then I generally either bore it completely on the lathe or if it's a big bearing mill the pocket to 0.5mm undersize and then bore it.

[dsc]

I would really only need skimming two parts as these are the plates where the the variable thickness adds to the overall depth of the whole construction and makes the side mounting holes move out of alignment.

As for the bearing housing, this was done on a lathe :O

Regards,
dsc.