# How to split tubes

Has anyone got an easy way to split the attached tubes? I need individual tubes that split at the half way point between the 2 tubes. When the tubes are square on with each other it is easy as the split line is straight so you just use split or trim with a straight line BUT these are not straight on to each other. Boolean union produces one item (I need 2 individual items), Boolean difference and split don’t split it at the half way point between the 2 items. If I really get stuck I’ll take the outside surfaces only and do a boolean split, hide one half, use the split line to create a surface and then use that surface to cut the original tubes. This is only a test of what I am trying to do as the real thing has 6 tubes all running into the shape at different angles and centres so if there is an easy way, it will certainly save me a lot of headaches. Thanks for your help in advance.SplitTest.3dm (293.2 KB)

It is not clear (at least not to me) what it is exactly that you are trying to achieve. What is “the halfway point between the items”?

Could you Explode the result obtained by BooleanUnion and then rearrange it to your liking?

You can try “Intersecttwosets” and select each of the tubes. It will create curves where your tubes meet. Then use that line to split each tube separately. You may have to loft the open edge to create a closed polysurface.

Here’s the file:
SplitTest_Marc.3dm (498.1 KB)

Very basic stuff. What I did and suggest you use:
-Work in shaded or wireframe mode so you see what is going on.
-Explode the two tubes
-Select on inside surface and trim the other inside surface. Select the now trimmed inside surface and trim the remaining inside surface
-Do the same trimming operations with the two outside surfaces.
-Join the surfaces back.
-You can join the two tubes together and you’ll have one object, as if the tubes were welded together, or you can create a surface, using Loft between the edges of the inside surfaces with the edges of the outside surface of one tube - and then repeat for the other tube, to keep two seperate objects.
-By working methodically, a pair of tubes at the time, you’ll be able to process as many tubes as you want.

Is this what you want? SplitTest DC.3dm (395.3 KB)

I intersected the two tubes.

I split the tubes using only two of the four intersection curves. The curves used where at the intersection of the outside surfaces, and at the intersection of the inside surfaces. The other two intersection curves were not used.

Unwanted split parts were deleted.

@davidcockey @Marc @ra_mull
Thanks Marc, David (and Ryan). You both arrived at the same result. I was hoping to avoid the loft or 2 rail sweep steps but I don’t see any other simpler way to go about it. Not that I have a problem with those procedures but when out of the 6 tubes I’ll be working with, any 1 tube is intersected by 3 others, so keeping track of where you are becomes a real challenge.
@menno Hopefully you can see what I was trying to achieve. Probably any of these methods would work but it seems there is no alternative to having to do 2 rail sweeps or lofts (see above).

Just in case any of you are wondering why I would need such a thing, I’m modelling some exhaust tubes and would like to try out the services of someone’s 6 axis laser tube cutter so that the pipe prep work will be already done. Obviously this will only be suitable for volume order jobs not one-offs.

In principle, if all your tubes are closed polysurfaces, you should be able to use BooleanSplit and delete the unwanted parts.

@Marc Not really because Boolean split produces the 8 bodies shown in the second screenshot whereas I need the 2 bodies produced in the first screenshot. I can’t any other method of arriving at this other than explode tubes, deal with the outside surfaces (various methods are possible), deal with the inside surfaces, then build surfaces between them (loft or sweep). As mentioned earlier, if the 2 tubes were intersecting each other at an angle but both in the same plane it would be just a matter of splitting each tube with a line or plane but unfortunately this isn’t the case.

Here’s the end result of the real thing and what I was trying to achieve.

Yep, you’re right, sorry.
I think that only a special function like “weldments” in SolidWorks would do this in some automated way.

If the pipes are linear, then a cplane set to the planar ends and Wirecut using the OD should work.