How do I add another circle around a cylinder

[jweaver]

Excuse the title… I am not even sure I know how to ask the question.

There is something that I have never been able to work out… Say I had a cylinder like this:

And I wanted to add “lines” around its peremeter:

Perhaps because I wanted to do this:

What tool would I use to do it? The only way I know is using the Push Pull tool and the CTL key… But I can’t believe thats the only way… if it was an object with straight sides (i.e a cube) I could easily draw lines around it… But how do you do the same for a circle, or a curved face?

[Box]

There are tools that will do it for you, but the most basic method is to copy the edges.

[jweaver]

Move tool? Was it that simple? I tried that but ended up with the top face floating in mid air… As always, i over looked the obvious… I think I was moving the top face, not the line.

Thats really helpful… Thanks for showing me.

Cheers

Jon

[jweaver]

What I am on the subject, is there any way to do it if the sides of the cylinder are not uniform or more importantly parallel…

If it was an odd shape, then its exactly the same, so thats good:

But what if the sides wern’t parallel… Thing of a cone.

Any tools to help in this situation?

[Box]

You can copy any number of faces down and intersect them to create new edges.

or Thomthom’s Quad Face Tools will allow you to insert rings among other things. But you need to understand quads.

[jweaver]

The first solution looks fine… Again, I didn’t think of that… Using Intersection is a perfect way to do it…

Thanks again… Really helpful tips

Jon

[Box]

Don’t forget that the face doesn’t have to be flat, so you can intersect a curved face with a curved face and create a complex curve.

[jweaver]

Cheers… I have used the Intersect feature quite a lot to do just that… That said, I still find it a bit hit and miss as I can’t remember whether to do “with section” or “with model”, and often have to do it a few times until I get it right… But I get how that works.

That brings me to another question which I might have to ask sepereatly.

Jon

[jweaver]

Last question on this topic… After I followed the steps, all looked good… But when I click on the new circle its a collection of straight segments, rather than a circle:

Is there an easy way to convert this to a circle? I already have and use TigWeld which seems to do the job… Is this the best tool for this, or is there a better way?

[Box]

There are various welding tools available, Tig’s is one of the better. I personally use Curvizard mostly.
Since you are using 2017 you need to use a weld extension, weld is now native in 2020.2

[jweaver]

Cheers… So this is expected behavour? Nothing I am doing wrong? TigWeld fixes it easily, but I just wanted to check that there wasn’t a way to ‘preserve’ the circle…

Thanks again.
Jon

[Box]

Normal behavior, it happens with follow me too, curves become exploded.

[DaveR]

Eneroth Auto Weld could be useful here.

[john_mcclenahan]

@jweaver

Is there an easy way to convert this to a circle?

Another way is to use an extension called Lines to Arc. I find this the most elegant and quickest way. It works on Arcs as well as Circles.

So long as the edges are all equal length (i.e., not modified from circle or arc segments) it will turn the loose edges into a SU circle or arc object, which is often more useful than a Welded Curve object.

The Lines to Arc object is a real circle or arc, and therefore has, for example, a radius property, and also a centrepoint which you can find by the usual inferencing methods, by hovering over one of the vertices to display the centre.

I’m not sure if Eneroth AutoWeld does the same - I haven’t used it much, and don’t now remember - @DaveR may know.

It’s available from the SketchUcation Plugin Store at [Plugin] Exploded arc lines to arc • sketchUcation • 1

Yet another option is to use an extension to find the centre from two edges then redraw the circle using that as a centre point. Chris Fulmer’s Arc Centrepoint Finder will do that trick, from the Extension Warehouse Extension | SketchUp Extension Warehouse.

This one is useful if one or more of the edges has been modified, for example by drawing a line to somewhere on the segment, not an endpoint - perhaps a diameter from midpoint to midpoint across the circle.

You need to use the same number of segments as the original to have the circle exactly replace the edges you have.

[DaveR]

Lines to Arcs is a good one to have. Eneroth Auto Weld does take care of it in many cases, though. Auto Weld is also useful for things like welding edges after Follow Me to curves in profiles don’t get exploded.

[Box]

Many many options for many and varied reasons.

[RLGL]

@Box

Many many options for many and varied reasons

Yep, some of the weld extensions work some of the time but not all of them work all of the time.

[dezmo]

Just another “33rd” way to keep the circle:

[DaveR]

And yet another way with nothing but Move.

.

[jweaver]

All good tips… Thanks… I have installed many Plugins over the last few days and am gradually playing with them to see how useful they are.

I was playing with some of the suggestions. And ended up with this shape:

I Tigweld will not join the circle into 1 edge unless I delete the traingles radiating from it… Is there a tool which will handle this kind of situation?

AutoWeld is paid, and not something I use often enough to justify the cost… So are there any others that will handle this? Or is it an impossible task?