Tween plane between two curves. This is ideal for making cutting planes for pipes that meet together at an angle. I created 3 versions of the macro.
Temporarily turn off the History recording and automatic deletion of the unnecessary helper objects (this is the most straight-forward version which most people will like to use):
! _History _Record=_No _Enter _Circle _AroundCurve _Pause _Pause 70 _Enter _SelLast _EnterEnd _SelLast _SetObjectName temp_object _Pause _SelLast _PlanarSrf _EnterEnd _SelLast _SetObjectName temp_object _SelNone _Circle _AroundCurve _Pause _Pause 70 _Enter _SelLast _EnterEnd _SelLast _SetObjectName temp_object _Pause _SelLast _PlanarSrf _EnterEnd _SelLast _SetObjectName temp_object _SelNone _Pause _SelNone _TweenSurfaces _Multipause _EnterEnd _History _Record=_Yes _Enter -_SelName temp_object _delete
Temporarily turn off the History recording (deleting the unnecessary resulting curves will not bring the pop-up warning for breaking the History):
! _History _Record=_No _Enter _Circle _AroundCurve _Pause _Pause 70 _Enter _SelLast _EnterEnd _Pause _SelLast _PlanarSrf _EnterEnd _SelNone _Circle _AroundCurve _Pause _Pause 70 _Enter _SelLast _EnterEnd _Pause _SelLast _PlanarSrf _EnterEnd _Pause _SelNone _TweenSurfaces _Multipause _EnterEnd _History _Record=_Yes _Enter
Keep the History recording (deleting the unnecessary resulting curves will bring the pop-up warning for breaking the History):
! _Circle _AroundCurve _Pause _Pause 70 _Enter _SelLast _PlanarSrf _SelLast _HistoryPurge _Pause _EnterEnd _SelNone _Circle _AroundCurve _Pause _Pause 70 _Enter _SelLast _PlanarSrf _SelLast _HistoryPurge _EnterEnd _Pause _SelNone _TweenSurfaces _Multipause _EnterEnd
P.S. I set a value of 70 mm, because I usually work with pipes up to 45 mm diameter. However, you can change the size to any other value according to your liking.