(Hi, John. Your email bounced. I tried to send you the FEM report.)

"John2005" wrote in message
ups.com...
The highest bending stress seems to occur right where the 2mm shaft
comes out of the 3/16" OD portion. With the .1875" long roller, the
maximum bending stress is 84,130.45 PSI, but with the .243" long roller
the maximum bending stress is reduced to 27,034.99 which surprised me.
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The magnitude is a bit surprising, but that it reduces stress is quite
reasonable. Stress distribution along the beam span is parabolic for uniform
loads, highest at mid-span and 0 at the supports.
******

The question now becomes, will the pressed on 3/16" OD center portion
act fairly close to a stepped shaft made from one solid piece as
modeled by the program ?
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My gut feel is to just go with it, but I don't have the investment and
responsibility you do. Anything you can do to smooth the transition between
the two should help. A fillet of silver solder, for example, will help
minimize the localized stress where they come together.