As if getting the Axis for a Non Linear Tube with constant radius is not difficult enough, there some cases where we need to get the axis of a Non Linear Tube that had non constant radius like this:
As you can see the radius is gradually decreases along the tube length.
Note: This step is for those HD2 license users
- Select the Extract icon
and select the circle edge with the largest radius. Choose Tangent continuity for Propagation type.
2. Select the Point icon
and select the extracted curve. Choose Ratio On curve length and enter 0.
3. Repeat Step 2. Enter 0.3 for the Ratio on curve length.
4. Select the Plane icon
. For Plane type, choose Through planar curve and select the extract curve.
5. Select the Line icon
. Line type: Point-Direction. Select the 1st point and select the previously created plane for Direction. For the End value, enter 20mm.
6. Repeat Step 5 with the 2nd Point.
7. Select the Isoparametric curve icon
Select the tube surface for Support. Select the 1st Point and Line for Point and Direction.
The 1st Isoparametric curve created should look like below
8.Repeat Step 7. Select the Tube surface for Support. Select the 2nd point and Line for the Point and Direction.
The 2nd Isoparametric curve should be created as shown.
9. Select the Sweep icon
. Profile type, select Line sweep. Subtype, select With reference surface. Select 1st isoparametric curve as Guide curve 1. Select the tube surface as Reference surface. Enter the Angle as 90deg and Length 1 as 30mm. Ensure the surface is pointing inward.
10. Repeat Step 9 with the 2nd isoparametric curve
11. Select the Intersection icon
. Select the two created sweep.
The Intersection curve generated is the center for the tube.
12. Hide all elements leaving only the Tube surface and the Intersection Curve to view them more clearly
