How modeling a complex object into a shape draw by a sharp line? After hours of tutorials, and the first help of Carlo, I'm looking in a way to force an object, like a "bone" (so not exactly a regular cylindre, with a lot of meshs) to shape itself into a sharpe path of 3 or 4 points (path converting in meshs after alt+C, let s call it "a guide"). 
So the idea is to use this guide like a tool to shape the bone object linked and without deformation (like a solid object) as you can see :



So to begin with... it s difficult : because it s not a bezier item, it s a complexe cylindre. So I can t use "bevel object"  with an object like that... 

After this step, I think there are two possibility to see the problem :

1) You can superpose pieces of the bone if they split on an exact point of the guide (so exactly on the point between two lines). I will know how I have to "cut the bone" (so remove littles triangles) to shape it exactly like the guide (with boolean union modifier for exemple!), but like it s an object more like a triangle long bone object, one of its faces is large and have to be always at the bottom part of the modeling...

So 2) No superpositions but a complexe serie of movements (spin, translation,..) of the pieces on after the other to touch themselves in a "solid" mode, to force the large face to be always at the bottom... 
Like that the little triangles removed will be much more smaller +++



I know it s very difficult to have the 2) option. S I think the first one with boolean modifier will be more than enought (but if you have an idea of course..).

Thank you so much for your time and help in this difficult modeling!!!!!
I think i found something, not really easy.  

Create an armature, enter Edit mode, make it flat and subdivide the bone (W, subdivide and choose the number)
  

In pose mode (Ctrl+Tab), rotate and scale your bones to fit the shape you need
  

Select all your bones and store the pose in the pose library, we'll use it later. Now cancel the rotation of your bones and apply the pose as the rest pose.
  

Now add a cube, in edit mode, move the faces to fit the armature and add an edge loops for each bone joint. back in object mode, parent the mesh to the armature (select mesh 1st then armature, Ctrl+P, choose automatic weights)
  

Now select your bone object (the thing that you'll cut) duplicate it with Shift+D, move the duplicate to the armature and parent it to the 1st bone (select the mesh then the bone, Ctrl+P, choose bone). Do as much duplicates as you have bones and parent them the same way.
  

Now select all your bones (armature) and apply the pose your stored earlier and clear the scale (menu or Alt+S)
  

If the cube mesh needs it, correct the vertex groups. This should be simple with a lowpoly mesh and few bones.
  

Now apply the armature modifier on the cube and in edit mode separate the elements (select and P). Add faces to close them.
  

Now you have 3 cubes usable as booleans to cut the 3 bone objects where you need. You can easily move the bone objects along their local coordinates for minor adjustments.