Setting up normals on a bevelled curve

Hello,

I'm trying to set up normals on a model similar to archway shown in the blog post about the normals editor. I'll use that image as an example:

In order for the top of the arch to be flattened, the normals I've drawn in yellow must be flat on the y-axis, but have different x vales to keep the curve on the top smooth.

Problem is - since the 'face' normal tool only does one face at a time - if I used it one by one on each face along the curve, while it would flatten the top it would also mess up the normals keeping the curve smooth.

Can anyone explain how to set up normals so that they're flattened in one axis without changing the other axises?

EDIT: I seem to have found a way to do it by setting up a mesh with the bevels removed and copying the normals over. But if anyone has an easier way to do this, I'd love to know, because it's a bit fiddly and unreliable.

Hello and welcome!

Yeah, right now it is the best way, unfortunately
But we'll think about something like "align by X axis" or so

Well, there's another way - by adding a loopcut and copying its normals, so there's no need to switch between objects/meshes :)