Sweep1 around cylinder

I have a curve around a cylinder that I would like to use as the centerline of a channel for an engraving cut on a 4 axis cnc. The path I have drawn follows the curve of the cylinder. I would like to show a 3mm wide by 4.5mm deep channel in my model. I have tried to use a sweep1 curve (with plans to do a boolean difference) with a 3x4.5 box, but because of the rotation around the A axis, parts of the back doubles over itself in places. I have tried adding extra “boxes” along the path to try and keep its shape but no luck. Is there a better method than sweep1?

pivot post v4 002.3dm (266.2 KB)

Hello - the radii on the sweep path have to be less than half the width of the box…


Can you suggest another approach to solve this problem?

This is the general shape I want to achieve, just a smoother finish, with an infinite amount of cylinder in the path instead of the 80 I put in.

Maybe make a smaller cylinder (4.5mm smaller) and pull your curve to it. For each curve, create a 3mm diameter pipe and intersect that pipe with the cylinders. Loft between those results?

Thanks Peter, I will try that