Follow me not filling my curved catenary dome

SketchUp
1

Hi All,
I have drawn a 2D catenary shape in AutoCAD and imported it into SketchUp. I then exploded the shape and drew a few lines and a circle for the follow me process (I scaled my model up by 100 before using this function to avoid a hole forming at its peak). After using follow me, the shape has no thickness (i.e. it is hollow). Please help. I need to print this on a 3D printer. Any advice for 3D printing?

Please note, I am new to SketchUp and may be doing a rookie error.

Kind Regards
Rich

Caternary Dome (before using follow me).skp (193.1 KB)

1215×808 116 KB

2

It’s still a scale issue, scale up another ten and it works fine.
The segments of your arc are 1.9mm, so when they become almost horizontal the vertices are getting so close together the become coincident to Su.

1 Like
3

Check the length of your edges, there are many less than 1mm in that model. The missing ones are much smaller probably.

724×502 54.3 KB

4

Wait, how small is this thing you plan on printing?

If this is scaled up 100 times - and the edges are still less than 1mm - this thing would be tiny. What printer would be able to print so small?

5

Sorry this is the true scale. 110mm in diameter

6

I scaled it up 10,000 times before using the follow me function and it still has no thickness. What am I doing wrong? haha

Caternary Dome (before using follow me) 2nd try.skp (1.1 MB)

7

Here it is scale by 10. Shows full thickness.

1 Like
8

haha, yes that’s exactly what I did. Maybe there is a setting wrong on my SketchUp and thus it is not showing the thickness, like yours does. Any ideas of why mine may not be showing up like yours?

9

Your original post image show a half ‘dome’ perhaps you just aren’t selecting both halves of the circle like I show.

10

I was just taking a section through the dome to show you guys that it was hollow. When I do follow me it looks perfect, but when I take a section, its hollow.

11

Yessss, sketchup is a surface modeller. If a hollow watertight shape is made into a group it will be seen as a solid, but it is always hollow.

12

Oh, sorry my bad. Will this be fine to print on a 3D printer then?

Thank you so much for your help! Really appreciate it!

13

Yes, basically if it is called a solid it will print as a solid.
There are other criteria for good printing, but that is another issue.

14

Yes, as long as the mesh is a manifold - basically, every edge is connected to exactly two other faces you are good to go.

You can use this extension I wrote to aid in checking your model:
https://extensions.sketchup.com/en/content/solid-inspector²

It’s not 100% correct all the time, but mostly.