1. Sorry, the file "prictice" created in version of FreeCAD 0.16. I replaced it in my previous post to "helix-BSpline" which created in v0.17.
2. When I test sweep tools, diameter of pattern in sketch for sweep is adapted to configuration of helix (BSpline), I set diameter to 0,15.
3. By my result:
I create helix by FCSpring macro
which is BSpline. In some variations of the BSpline created by this macro "Utility to sweep" from "Part" tool causing either Input error "TCollection_InddexedDataMap::FindFromKey" or crach of FreeCAD if "Frenet" option is disable. Model which causing crash created in v0.16. Position of the sketch, which is revolved is set through "Base" section of object properties.
Behavior of the model the same for v0.17. (add file "error" with BSpline generated FCSpring which call error, file "crash" contain BSpline, which cause crash). With "Frenet" is enable, this tool worked whell even if the diameter of circle admits an intersection.
With this it is clear. It needs a message on bugtracker.
4 chrisb said that he got some results with sweep from "PartDesign". My attempts to repeat it are unsuccessful. Even more, I can not reach
the result with "sweep tool" when i use v0.17
a) If I create spring in v0.17 whith new body mechanism, "sweep tool" message error "Link go out of the allowed space" in result. (add file "v0.17")
b) Tool "Sweep a selected sketch..." say "TopoDS::Wire" (file v0.17")
In this regard, I have questions:
a) Is It some wrong in BSpline which generated by FCSpring macro
b) How possible make any sweep ("sweep tool", or "sweep a selected cketch...") with such BSpline in v0.17?
PS in version 0,17 position of sketch setup by "Attachmen" section of ObjectProperties. When the file reopen sketch lost given orientations for some reasons.
Sorry, for my english.