Tapering Train Rail

[@MOTOMINING]

Maybe it doesn't matter, but I'm thinking you've produced a slightly concave surface by doing it this way.

[@RuudAlthuizen]

Putting the taper in the fixture, by raising the part on one side would have helped. (Coming from an armchair “machinist”).

[@Regal4555]

If the part is level, and the spindle is square, there is no concave surface. The taper was done in program.

[@MrSmithDotShop]

Good catch. The concave is about 0.006", well within the tolerance. The customer didn't feel that would be an issue as the edges and crown will be ground into the rail following installation. Milling off the excess simply saves a lot of grinding later. If this was to be the final shape we would have fixtured it so that it could be milled perfectly flat.

[@shanerorko8076]

​@Regal4555 what were you saying?

[@MrSmithDotShop]

I'm saying I'm stupid... it is concave at the leading edge but once the centerline of the tool pass over it is square to the tool. I did offset the cut by 0.0347" to address the leading edge. The 0.006" came from me looking at the leading edge in CAD with concave on in my head. Simulation confirmed it was flat.