All require an elevation template - which I would expect to make on paper, by securing the paper horizontally along the wall(s) and following the ceiling/wall join above with a hanging weight. Or similar.
Method 1: Somehow transfer the elevation template to the big CNC software system, along with the profile of the picture rail. A second pass will be required to make the rebate on the back for the picture rail hooks to hook over,
Method 2: Physically mount the elevation template on a suitable piece of soft(ish) wood. Follow it manually on the bandsaw. Set up a series of router or spindle-moulder cuts to create the picture rail profile and the rear rebate.
Method 3: Use a genius idea from the woodworking members.
Looking forward to replies.
The Bassman (Sam Wise)
A good way of templating a curve like this is with hot glue and cardboard. Prop/tape/wedge a big bit up against the wall, then hot glue on strips to build up the curve. You only have to trim the ends to get a good match and can keep on snipping and rearranging till it fits well.
A similar way is to use pointy strips and just pick up key points, then use a thin batten on nails in a bit of ply to spring the same curve.
I can’t imagine the CNC method would give you the best surface finish. Not without a lot of post-processing anyway!
Using the spindle moudler would be tricky too. You’d need two passes for the up and down facing sides. And you’d be coming at it from the “wrong direction” IYSWIM. It would be a very wide spindle stack with a pretty shallow slope.
(You can’t come at it from the “right” direction because the piece has a concave curve)
You could consider doing it in fibrous plaster, which would be the traditional method. You’d need to make a rough oversize mould and then a copy of the profile (use the hot glue method in miniature or I think the space has a profile guage?) to make a scraper to bring the cast into shape.
Not quite sure how you’re going to hang pictures on a slope mind you!
