Problem with "project to surface" on radially asymmetric models

[mauro.antonioli]

Hi all,

I'm having issues in with the "project to surface" command. I design my own handles and usually I create them through the revolve command like the following one:

Usually I also add coiled material on the surface to allow more "grip". To do so, I create a coil starting from the base of the handle, then use the "project to surface" command to project the coil on the surface and finally I use the "sweep" command to model the shape of the coil around the external surface:

Model the coilProject the coil to surfaceSweep the coil onto the surface 

Up until now it worked flawlessly but today I wanted to do the same with a new handle, which is NOT obtained by revolving a shape around the center axis. The new handle is lofted  from different shapes (the base is a circle, then it transforms into a slotted figure) so the main difference with respect to all my previous ones is that its design is lacking "radial symmetry". Here's an example of how it looks like after having created the coil around it:

 

Now, if I try to create a new sketch and project to surface the coil this is what I get:

The projected curve is limited to the purplish short segment you can see at the center of the handle. I tried to play with the options of the project to surface command but I haven't been able to find a way to solve this. I think it has something to do with the indications of the projection type being set to "closest point" but I don't understand why the projected line I get is one on the "farest" position of the surface from the coil. 

To better understand what I mean, take a look at the following image: I re-created the same issue by breaking down the model in the center as a parallelepiped. As you can see, the projected line on the model surface can be seen (in red) only on one of the four faces and not even the first one that the line "encounters" along its path.

Can anyone explain whether this is an actual issue of the "project to surface" command or just the way it behaves when it comes to project lines "around" other models?

Thank you all in advance for the help.

Mauro

[HughesTooling]

Lot easier to help if you export your f3d file and attach. Anyway you will be better off using sweep in the patch workspace to create your helix then extrude\revolve set to intersect.

Then extrude include to create the path.

Note the swept surfaces are not as segmented if you use a surface edge as a path. See attached f3d file.

Mark

[HughesTooling · Accepted solution]

Here's another example to show why you should use a surface edge rather than project to surface. The surface edge is more accurate than the spline created by project so you don't get segmentation. Used a pipe in this example to create the helical grip.

Mark

[mauro.antonioli]

Hi Marc,

first of all, thank you for your reply. Secondly, you're absolutely right:

(1) I would have been a lot easier if I had added the Fusion file, I'll remember it next time.

(2) Your solution is much easier and more effective than mine; unfortunately, I'm not that familiar with surface modeling as I should be! It's something I've procrastinated far too much and I feel like it's about time I start digging more into it.

Thanks again.

Mauro