I would try something like an extra one eighth rib on the outside rim. It
is only four inches in diameter so that should do it. It will locate your
weld closer to the neutral axis of the disc.
I agree with one comment about overwelding. Can you shrink the assembly
on and just put a couple of locating tacks in???
I worked for a company that build wheels for ore trucks. Their original
design called for simply shrinking the rim onto the steel centerpiece. No
weld was required at all. Later designs had just a little bead to locate
the rim on the centerpiece. These were big wheels handling hundreds of tons
payload.
Your solution will end up being the combination of all the contributions
here.
Yes you are right about letting your assembly cool after welding. Warm to
the touch is OK.
Randy


"Terry" wrote in message
ups.com...
snip
I could add some ribs to the flange, but I would have to start out with
a thicker piece and take off a lot of material. How tall and how many
ribs would you recommend for an 1/8" thick flange. It is about 4"
diameter with a 1 1/8 center bore.

I don't have the option to weld first and then machine. My mill does
not have the Z travel to accomodate my hub.

Before I begin machining a new hub I will try the old hammer and dial
indicator trick to see if I can true up my flanges. Maybe I'll get
lucky this time! Thanks.