Hi all,

Was hoping someone could help me with this problem I've been battling with for a couple of days. I have a 3D sketch with a helix (created by converting entities). The axis of the helix is vertical (the Y axis), the line is sitting on the top plane along the Z axis. I have an arc connecting the two but if I make the arc tangent to both the helix and the line then the sketch is over-constrained. If I remove the relation between the helical spline and the spline from which it was created, then I can have the arc tangent to both the line and the helix, but the helix is under-constrained. Any ideas on how to tackle this? I'm pretty sure that an arc that is tangent to both is logical and ought to be possible. I've attached a picture of the sketch and the part itself.

Thanks,

Francis

To do as you described, an arc tangent to both line and helix, the line cannot be on the same plane as arc and the helix endpoint. Create a 3DSketch, insert a line parallel to a plane perpendicular to the helix axis, insert a 3 point arc connecting the end of line to end of helix. Then make tangent relations between the arc, helix, and line. To get the arc endpoint coincident with the helix endpoint, you may need to use Convert Entity on the helix. The correct solution will have a line offset down a little from the helix endpoint and the arc will be at an angle matching the helix angle.

See attached.