Blending Surfaces For file

I have this file and I’m trying to get these grooves to fade into this upper surface. Can someone tell me how I would do this?

VolKnob4.3dm (627.1 KB)

Here is the file

Several different methods:

Quickest is first step is to explode the polysurface and work with only one of the curved strip. Use MatchSrf with Match Edges by Closet Points option to match edge of the curved strip to the cap. Then use ArrayPolar to create the other strips.

An alternative is to rebuild the curved strips so that they blend into the cap. Revise the edge curves for one strip so that they have the desired continuity with the cap surface. Then use Sweep 2 or NetworkSrf to create the strip.

What is the match edges by closest point option? I’m fairly new to rhino.

Are you talking about doing it like this?

I got it! Thank you so so so so much! You have made my day!