Sweep profile not going along the path fully...

[prajwal]

I am trying to sweep a profile throughout the helical sweep path which is a series of 3d sketches. The sweet prifile sweeps correctly to the first 3d sketch profile but whin I select the second line the preview is gone and Inventor gives me an error saying the sweep cannot be done. Any ideas on how I can have the sweep done throughout the helical structure.Attached is the ipt file.

[JavaLodge]

I looked at your file and I couldn't get it to work either.  In a file of my own I tried to make a sweep out of two 3d sketches and it worked.  I think your problem is that the ends of the sweeps aren't coincedent with each other.  If they are coincedent Inventor will recognize all of the 3d sketches as one path and will automatically select them all for you.  Hope this helps.

[glenn-chun · Accepted solution]

Hi prajwal,

To resolve the sweep issue make the path tangent-continuous (G1).  I will show you one way to make your constant-pitch, variable-radius helix smooth.  The attached part is your original part with the following steps added.

1. Create a revolution surface from a profile that uses the variable radii.  I added a sketch fillet between two adjacent lines in the profile.  I used a radius of 10 inches for each fillet, but you might want to change it to a smaller value if you want each "transition area" in the final result smaller.

2. Create a coil surface from a linear profile.  The line starts from the helical axis and its length is a little longer than the largest radius among the variable radii.

3. Create a 3D Intersection Curve between the coil surface and the revolution surface.  This is the new sweep path which is tangent continuous.

4. Make your sweep profile (SweepPattern) fully constrained.

5. Redefine the workplane for the sweep profile by selecting the start point and the start curve of the new sweep path.

6. Make sure to project the start point of the sweep path into the sweep profile and constrain the sweep profile to the projected point.  This is very important to make sweep work properly.

7. Sweep the profile along the path.  You probably want to use the pull-direction sweep instead of the regular sweep.  The pull-direction of the sweep is the direction of the helical axis.  In your case, the X-axis is the helical axis, so select the YZ Plane as a Guide Surface.

Hope this helps,

Glenn

Autodesk ShapeManager Development

[prajwal]

Thank you so much GlenChun for the illustration of the process. I would definately make the radius smaller and the 3d intersection method makes it work smoothely. Exactly what I was looking for.