Pekka it's quite a bit of support in reality (pics don't show it as well) the shears are 9" long and made of zamak ZA-2, which is stronger than CI. There will be 1/4" 1" x 9" steel underneath. We're talking 9" x 7/8" total thickness along the way for the front shear.
Also under the 3" wide center section, you're looking at about an inch of upper section thickness bearing on the way.
By contrast the Gingery has 2-1/4" wide center section, and no support wings, and is cast in aluminum. So, 2-1/4" of support along the ways.
I just judged it was sufficient. And a heck of a lot more support that the Gingery, on what is basically the same size lathe. The rear shear was made thicker because it lacks width, but the front shear section is pretty wide so I didn't think it needed more support. Also I wanted to be able to tap and bolt nto the reaar shear -- that was already do-able in the front, past the sliding edge. There is 7 pounds of material in that casting, and I didn't want to pour more than I felt necessary with the crucible topped up as it was.
In other news.....here's the back of the apron in case anybody is interested. the points are from vents pushed up in the sand, and as you can see there isn't any shrink cavity, so should machine easily.
