maxh3
Mechanical
- Dec 10, 2010
- 77
I'm working on a beach chair model and the fabric will attach to the frame with lacing to a zig-zag bent wire welded to the inside of the frame. See here for an example of a chair that uses this kind of fabric attachment.
It's kind of hard to see the zig-zag bent metal wire that's welded to the frame, but look closely.
I thought long and hard for a good way to model this, and I was able to do so on flat chair segments all on one plane. I created a sketch for a sweep path by offsetting the sketch used for sweeping the aluminum tubing of the frame. Then I did a surface sweep with a line segment perpendicular to the sweep path sketch and choosing "twist-along-path" in the options, to create a helical shaped surface. Then I did a surface sweep along the same path with a circle to create a tube shaped surface. Then under sketch tools I used an "Intersection Curve" to create a helical curve along the path of the frame of the chair, from the intersection of the two surface sweeps. This process is illustrated here:
I was able to then create a new sketch on the plane of that chair piece (foot rest) by using the "Convert Entities" sketch tool on the helical curve I previously generated. It looks kind of like a sine wave following the offset path of the tubing frame of the chair. I then swept a circle along this to create my zig-zag bent wire welded to the frame of the chair (see attached pic; the fabric doesn't yet have grommets or lacing...)
However, now I need to do this on a part of the chair that's not flat/planar. How can I do it? Can I somehow do the same process to create a helical curve along the required path, then project that onto a curved surface to create a 3d sketch all on the curved surface? Or is there some other way to generate the curve, such as equation driven?
It's kind of hard to see the zig-zag bent metal wire that's welded to the frame, but look closely.
I thought long and hard for a good way to model this, and I was able to do so on flat chair segments all on one plane. I created a sketch for a sweep path by offsetting the sketch used for sweeping the aluminum tubing of the frame. Then I did a surface sweep with a line segment perpendicular to the sweep path sketch and choosing "twist-along-path" in the options, to create a helical shaped surface. Then I did a surface sweep along the same path with a circle to create a tube shaped surface. Then under sketch tools I used an "Intersection Curve" to create a helical curve along the path of the frame of the chair, from the intersection of the two surface sweeps. This process is illustrated here:
I was able to then create a new sketch on the plane of that chair piece (foot rest) by using the "Convert Entities" sketch tool on the helical curve I previously generated. It looks kind of like a sine wave following the offset path of the tubing frame of the chair. I then swept a circle along this to create my zig-zag bent wire welded to the frame of the chair (see attached pic; the fabric doesn't yet have grommets or lacing...)
However, now I need to do this on a part of the chair that's not flat/planar. How can I do it? Can I somehow do the same process to create a helical curve along the required path, then project that onto a curved surface to create a 3d sketch all on the curved surface? Or is there some other way to generate the curve, such as equation driven?