# How can I scale curved surfaces radius but leave its width alone?

I have a curved set of faces, made by creating 2 circles, joining the objects and then joining the verts I needed while removing the others.

Unfortunately the resulting object has the wrong radius. See pic

Is there any way that I can scale it so that the radius changes, but the width of the faces remains the same? In effect what I want to do is tighten the curve so that lowest edge (in the top ortho view) is much closer to the top, as indicated by the yellow arrow.

Yes, so long as you know the center of the radius.

Place your cursor at the center of the circle. Change to cursor pivot with . key. Select your mesh. Use the push/pull operator, available from spacebar search, or from the mesh/transform menu. Move your mouse until you're happy, then LMB confirm.

• Many thanks for the idea. I may be getting this wrong but when I try the whole of the arc's radius changes where as I just want to reduce the size of the radius in the y axis moving the faces in the direction of the arrow. If I try and constrain the push pull to the y axis then the faces just move on y, with the exception of the top most edge which stays fixed and the object folds over on this. - i.imgur.com/snT4aPV.jpg .The faces do stay the same size, but its still, unfortunately not quite what I need.
– John
Jun 23, 2018 at 12:11
• Okay, then you don't want it be a circle anymore, but there are more dimensions to that, there's no single perfect operator for it, no exact answer to match your geometry. The easiest thing to do is to use proportional editing while translating both sides of the bottom in the direction of your arrow. Another option would be to recreate the shape with a 2D curve. Jun 23, 2018 at 16:24
• Sorry yes, thinking about this more I really need to make the internal radius more elliptical. Would it be possible to use weights? If I somehow assigned weights based on selecting the end I wish to move? I confess I have not used vertex weights and the info I have found suggests these are for armatures and skins, rather than mesh modelling. Would what I am thinking of be possible? Can I select a set of vertexes and then move them so those linked move depending on the distance from the ones select? Would that even work as an idea?
– John
Jun 23, 2018 at 20:22
• It is possible, and vertex weights are for anything you want (I sometimes use armature deforms as modelling techniques, as an example.) There is never anything wrong with trying out a new technique, it's how you grow, and there's no need to ask-- just try it out and see! However, in this case, I don't think using vertex weights will end up making it any easier for you; it's just a extra layer of abstraction. Jun 23, 2018 at 21:32

You can either go to edit mode use box select and resize it or press s then y. This will scale the mesh only in y-axis