Creating a Compound Radius

How can I blend a radius on the top of this surface ? - I have drawn an arc and attempted to use the follow-me tool to drag it around the top but that does not seem to work ?

It’s usually easier to use FollowMe by preselecting the path before you start the FollowMe tool, then clicking the profile face you want to follow that path, which should be in the same context.

What size is your model? SU doesn’t work well with very short edges.

If you can upload your model, not just an image, someone can help you more quickly and without having to guess what’s wrong.

I addition to what @john_mcclenahan noted about technique and size (which we can’t estimate from an image) you will have problems because the profile is not perpendicular to the starting segment of the arc you want it to follow. This situation will usually cause issues with the ends of the extrusion not starting or ending where you expected.

Thanks John;

It’s small, all my projects will be small as I am using sketchup for re-engineering small parts.

I have attached the model, all of the vertical ‘pillars’ need a compound blended radius on them.

base-4A.skp (1.2 MB)

You really should be working at a larger size for this kind of stuff. Either scale up by 1000 and use meters as if they were millimeters or use “The Dave Method”.

Is this what you are looking for?

Yes, that’s exactly what I am looking for, how did you do it ??

I’'m heading for bed - after midnight in UK - but you are in some of the best hands on the forum.

Why does the middle column in your model not have an arc but just edges at the top, and unsoftened vertical faces?

@john_mcclenahan - well actually the top of all 3 pillars should be the same compound radius

Yes, it looks as if it ought to be. Just wondered how they got to be different.

Easiest thing is probably to delete the old column, and redraw it properly.

What radius should they have? They are have different widths.

Hmm, well they should all be 3mm wide, but it has taken me 1/2 day to get this far and no doubt with the undoing and testing to try and get things to work I have inadvertently changed some dimensions.

But these are not critical dimensions, ideally they would all be 3mm wide :slight_smile:

It would help if you increase Display Precision. They you could see the variations. It would be easier to do the rounding if your model is more precisely drawn.

What version of SketchUp are you using? Please complete your profile.

1 Like

I’ll pick up from after you have either fixed up the model’s inconsistencies or decided to live with them.

The key tricks to creating the corner using just built-in tools are:

  1. Make a component of your model so that you can apply “the Dave method” to work on a scaled up copy. As is, it is too small and you are going to encounter issues with SketchUp’s handling of small edges.

  2. Open the component for edit, copy the curve at the top of the column, close the component and then do edit->paste in place to get a copy outside the component. This lets you do additional manipulations without pulling the other geometry along.

  3. Rotate the curve around the red axis so that it stands upright atop the column. Copy this, open the component for edit, and again do paste in place to put it inside the component. You can draw an edge across the bottom of the curve and then push pull it across to the other side to create the curved top part.

  4. Draw a sphere outside the component. Erase three quarters of the sphere to create the rounded corner. In my experience that’s easier and less error-prone than trying to do a follow-me for just a quadrant. Move the quarter sphere into place on the component without opening it, and then rotate and scale as needed to make it align with the vertical and horizontal curves on the column. Then cut the adjusted quarter sphere, open the component for edit, and paste in place.

  5. You will no doubt need to clean up some internal faces and or stray edges before SketchUp will consider the component to be a solid.