Usage Description - Brute forcing a hex perforation

[big_red_frog]

This thread is to answer a question raised on my halo helmet project on the technique used to generate the perforated visor.

https://fusion360.autodesk.com/projects/halo-4-helmet-keyshot-render

"- quick question! How did you go about creating that honeycomb cutout on the visor portion? When I've tried to accomplish this on a curved surface, like the visor, I create a sketch on a plane, but the cuts are then not normal to the curved surface. How are you doing it? I'd love to hear"

The hex perforation was an attempt ( successful ) to 3d print a visor which could be seen through and adhere to the specific dimensions of the helmet itself.

The Hex shape is chosen as it will print vertically with little to no supports, the structure is self supporting, and the opening / closing of the hex shape doesnt tax the ability of the printing process to build out.

I was actually quick stunned when the first attempt printed so cleanly, and it solved the need.

http://www.thingiverse.com/thing:165110

I am however more proud of the vac form version which is described here...

http://projects.hackaday.com/project/254/log/377

Anyway, back to the technique.

If I was to do this again, having spent a little more time with the pattern commands I would likely leverage those now, with a circular pattern of a vertical set of two columns of interlocked hex. I would be happy for someone to tell me there is a “magic” way!

However, in this case I am afraid to say I brute forced it 😞

All images are taken from the current model, where I had enough of the construction work still present. So it will look a bit odd, I worked with just one half and mirrored the final result, and you see many of the artifacts of the completed process, I haven’t recreated from scratch. So all the hex holes are already in place.

This was basically achieved by :-

1)      Start with the visor model, which is solid

2)      Draw a circle of the approx. dimension as a rough guide

3)      Draw a set of lines in the same plane that divide the effort into 4 steps, using the top view, so they track the main shape of the visor itself rather than the cirle. ( the circle was a red herring )

4)      Make vertical construction planes on each segment of the line.

5)      Establish a sketch on the first front plane, and construct your hex pattern with the desired gap.

6)      Select and extrude the hex’s as a Boolean cut into the visor ( note this image shows the second set, but you have to start with the first before proceeding to… )

7)      Copy the hex pattern sketch to the next line segment vertical construction plane. ( you can see all the hex templates already in place here, but you would be progressing through, because you have to build on the previous punch out result… )

😎      Using the “look at” function align the view directly to the sketch of interest, then manually align the sketch to get a satisfactory coincident with the previously punched out holes, this is the brute force bit. You can see how it doesn’t line up with the other sketches, it needs to line up with the punched holes in the visor to the left.

9)      Repeat the extrude and move on. You may have to change your original construction planes if things don’t look good enough, tweaking the implied distortions around the curves horizontally. Its an iterative process. And as the shape changes you only extrude those hex’s that you need.

Well that turned out to be more text than expected, and I will now hide somewhere while someone tells me what I should of done…