Join non coplanar 3D strings

[tingleyr]

Is there a way of joining 3D srings that are not coplanar, I have a series of cable runs that duck and dive all over the place and want to join them such that i can extrude the diameter of the cable.

This can be done by opening a CAD drawing in another proprietary softaware package very easily, however this cannot be re-imported back to AutoCAD

[jaberwok]

If they contain only straight segments you can use 3dpolylines but you will need to trace over the existing ones as they cannot be joined.

[tingleyr]

Unfortunately the path does not just contain straights. Because I am showing cable runs through a tunnel, the diameter of the cables limits the curvature to 3500mm.

[jaberwok]

Sorry then, the answer is no.
The nearest you can come is to select 2 or 3 (possibly more) runs which can be made effectively co-planar by creating a suitable UCS and joining those runs into a single (2d) polyline.

Apologies in advance if this is too basic -
Obviously runs that zigzag across a floor can be polylines but, by creating a suitable UCS, runs that zigzag across a wall can also be made co-planar and can then be made into polylines.

[mmccarter]

This is a task which our company frequently need to perform. As jaberwock said already, this can not be done in AutoCAD.

The closest solution I have found is a routine called "pedit3d". If you google for this you should be able to find it. I can't remember how much the routine costs, but it's not much.

The routine works by doing what jaberwock said. You select the lines/polylines/arcs/arcs on non planar UCS etc that you want to join and then the routine traces over the top of them in the current layer. This obviously creates a copy which is joined, so the first thing to do after running the command is to erase previous so you are left with just the joined line.
NOTE: As AutoCAD can not join arcs to anything non planar it creates short chord segments of straight lines. The length of these can be altered but I find the default settings are generally ok. This does create problems if you want to use your joined line as a path for extrusion as there are so many vertices along where arcs used to be.
NOTE 2: This routine comes from Germany I believe and sets the units for angles to radians and then back to your previous setting again. Beware that sometimes your units will not revert back and rotating things suddenly goes haywire!

I've never considered trying to join such entities in another program such as Microstation or Rhino. I'll give this a try when I get a chance and report back here.

[tingleyr]

I was not going to mention other software, but as you have Microstation will join non coplanar elements only you are then committed to use that platform to extrude the element. Don't know what happens to them if you saved it as AutoCAD