# How to split a tube obtained through sweep

Hi,
I am trying to model a 3D tubular structure composed by different elements with different materials (see attached mages). I first generated a 3D free form line, I used the function “around curve” to have a circular section perpendicular to the spline and then “sweep rail 1” to sweep the circle along the spline. I also add some thickness to the surface with the function “offset surface”. Now I would like to separate my tube in parts with different lengths (see figures), so I can assign them different materials. How can I do that?
FYI the original spline (i.e. the rail of the sweeping) is a 3D curve so my tube doesn’t lie on any of the cartesian planes.
Please let me know if you can help me!
Thank you,
Mary1

Hi Mary, I hope this isnt a stupid answer, but the 2 lower surfaces look like simple curve extrusions . While the top one looks to be a tubular solid . Could these be built as individual parts and then give them the material you need?

maybe before doing that part, run the `Split` command on the single surface… then choose the Isocurve option and set the direction. (the surface will split where ever you click the cursor)

after splitting up the surface, then use offsetSurface for thickness… (you should be able to offset all the segments in one go)

edit… assuming you’re going for something like this… a pipe that’s been divided into smaller individual sections:

Hi markintheozarks,
thank you for your prompt reply. You are right, in the figure they look as extrusions (the figure is just a simplification). However, In reality the axis of the cylinders is not a straight line, it is curved. This is why I decided to use the sweep rail 1.

I have just found out that I can create a cutting surface perpendicular to the axis of the spline by:

• set cplane perpendicular to the curve
• set cplane elevation
• drawing a rectangle on the new plane
• split tube using the rectangle as cutting object.

However, the split is not working. it seems that the tube is cut in another direction. I am attaching the file for your reference.

tube_split.3dm (267.5 KB)

Jeff,
this is exactly what I want to do

• when I use the command split, how do I set the direction?
• is there a way to set a predefined height instead of clicking a random point with the cursor?
• I assume at this point I don’t need a cutting surface (see my first reply to markintheozarks). Is this correct?
Thank you so much!
Maria

[quote=“mary1, post:5, topic:23159, full:true”]

• when I use the command split, how do I set the direction?[/quote]
i’m on a mac so i can’t exactly help there… someone else will have to… but there should be a toggle option for the direction in the command line after choosing Isocurve in the split command.

[quote]

• is there a way to set a predefined height instead of clicking a random point with the cursor?[/quote]

if you use the command `Divide` on the surface seam or the original curve-- divide by amount of segments or length per segment… a group of points will be placed along the curve… you can then snap to these points when splitting.

[quote]

• I assume at this point I don’t need a cutting surface (see my first reply to markintheozarks). Is this correct?[/quote]

you could use one and it’s possible to get them in there properly but probably more confusing…
if the tube wasn’t easy to reconstruct then using cutting surfaces might be better but in this case, better to just start over.

Mary1,
When you use the split command and go for the “Split by Isocurve” option you can use the “U” or “V” keys in the command line to change the direction of your splitting line.

It worked perfectly!
thank you so much to all of you for your help!