How to cut out a recess?

Hello could someone give me a quick steer please on how to cut out a recess in a ring? I’ve managed to make a channel ring. I want to inlay a strip of flexible material in the channel and then glue the ends of the material into a recess at either end to secure them and hide their ends.

So far I’ve made a channel that goes most of the way around the ring, leaving a solid section at the bottom.

Can anyone advise how to go about cutting the recesses please? The recesses need to project say 3 mm into the solid section either side. I presume I need to create a cutter and extrude it and use Boolean to cut away the solid? I’m not too sure how to do this on the curve so the curve matches?

Or there may be an easier method?

I attach screenshots of the channel ring so far.

Many thanks for any suggestions.


Hi Diane - it is probably fairly simple but I’d need to know more about what exactly you’re trying to do and where on the ring.


Hi Diane,

I’m not clear what you mean by this part of your request. If you are looking for a smooth curve where the flexible material goes under the surface, something like this:

then may I point out that this will leave you with a knife edge at the edge indicated - this would be a vulnerable point in the finished ring.

If your flexible material can accommodate it, I’d look at making the recess closer to perpendicular from the surface: this would be stronger and easier to manufacture. I would do something like this:

(This is a simple circular ring and I’ve spaced out the elements to show them more clearly - in reality of course they have to be co-located.)

  1. Start with some 2D construction aids to set the various radii and recess ends.
  2. Create a tube to form the body of the ring.
  3. Create another tube to start to define the material to be removed to form the channel.
  4. Split this tube close to where the channel ends (within the confines of the two boxes in the next step). Delete the unwanted part and Cap the ends of the wanted part to make a solid.
  5. Create two boxes where the recesses need to be cut out. One way is to loft 2d outlines.
  6. Take the ring and use boolean difference to remove the channel and the recesses.

HTH (if not, then post your .3dm file and give more detail and someone will try and do better!)