Agree the reduced side angle iron is OK for fence.. Clean out the back rail screw holes and use almost that long screws. back rail should end rest perhaps .015 off the chuck top and be able to raise to perhaps 3/32 away..You have to be able to wheel skim it with a grinding wheel when in place...Have special wrench that is shorter than standard length because you don't want to over tighten. two finger tight is a good rule.starting center and working out....put a screw in the holes when not using back rail. Place work all about the chuck not only at front center on the rail..yes have some lay-downs so you can get work away from rail so to use all about the chuck.
You can split the angle with a parting wheel easy enough..down feed on the grind side and go across..watch that end to se that you don't go into chuck..at about .020 left you can break off the waste..
Saying there is a .003 chuck center hump is not very meaning full. Is that the chuck flatness or the travel of the machine long travel.
I like to plate check a chuck to see the bottom is flat, If it is out of flat how so. Bowed concave or convex.
A little bottom bow convex an the hold downs will make to straight on the bottom so might let that go.
Bowed concave bottom and the hold down won’t make it flat so would grind the bottom...
shim each long end and check for flat is an Ok way to check. and then put a same shim under the middle and have some idea about the top..consider the weight might make a few tenths from unsupported weight with shims outboard.
But is the grinder capable of grinding anything flat? For this proof /test I tale a long straight parallel, lay it long ways , shim up the ends Zero-Zero and run an indicator along long travel..Do the sane for cross travel. Simply indicating the chuck mounting pad can give some idea about the grinder's grinding ability once it was check with a straight edge for being flat.
Grinding a chuck is likely the toughest grinder job.. heat makes them swell and once burned they are never the same..I tell new grinder hands to develop a feel for grinding before grinding a chuck..Even if you have to pay a grinder hand to do it, that might be worth it.
46 h to k very open wheel is the ticket//Some even use a 36 h to k very open wheel. Wet/Coolant grinding only, with a pause at both ends to let the chuck have time to cool.
looking on the youtube you often see a guy skimming a chuck..a few tenths or a few thousandths to make it look easy..It is not easy and a good way to mess up a chuck with trying to make a quick job of it.
