Cura - Closing off top and bottom of Open item

General Software
1

SO I have a part that is essentially a tube with compound curves. While one end is open it does have a large flange so I made that the print surface.

However, Cura either wants to close both ends off completely or not at all. Here you can see the original drawing, note that you can see all the way through.

Open_both_Sides.jpg
Open_both_Sides.jpg960×1010 132 KB

When I get it into Cura - in Ghost view you can see the flange at the bottom
Ghost_No_top.jpg
Ghost_No_top.jpg921×701 128 KB

So with Bottom and top >0 I get a solid closure over both open ends even though the drawing has no top at all or solid bottom
Solid flange and firewall_1.jpg
Solid flange and firewall_1.jpg921×701 128 KB

Solid flange and firewall_2.jpg
Solid flange and firewall_2.jpg921×701 145 KB

Ok fair enough, set top and bottom to 0 so now when I show the layers I do not get the flange that IS in the drawing. So, I either get a roof that can not be printed and a solid layer on the bottom where it should be just a flange OR I get a no flange at all on the bottom.

So what dumb noob mistake am I making! :slight_smile:

No_Flange.jpg
No_Flange.jpg921×701 146 KB

2

I am not an expert with Cura but I do a fair amount of CAD work.
In your second picture it looks like your model is just a single surface shell.
I would think you need to complete the model so that it includes the outside, inside and end surfaces, and defines the wall thickness you want. This would all be done in your CAD program before you even get to Cura.
With thinish walls I try to always make the thickness a multiple of the nozzle diameter. Seems to be easier for the slicer to deal with.