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Re: Another ULTIMATE CHALLENGE
The mobius I made took a while. I am a Unigraphics user, and have been for 14 years (since version 7, I think). I probably had 20 hours into this design, over the course of 2 months (most were during lunch hours). This was a swept solid, through a series of the same profile. Here were the steps taken:
1. Make the 2d profile of the mobius cross section (in this case, it had 2 grooves in it to contain the 5/8" steel balls).
2. Save the profile created in step 1
3. Open a new part, draw a circle that will be the centerline through the mobius will flow. This circle was 7" in diameter, if I recall correctly.
4. Import the profile from step 1, placing it so that the center of the profile is on the 7" diameter line, at 0 degrees. I did this by moving my work coordinates to that point and importing the profile, instead of moving the profile (you'll see why I did this shortly). For reference purposes, the Z axis was pointing toward the center of the circle.
5. I moved my work coordinates up the path of the circle, at 45 degrees, and then rotated the work coordinates 22.5 degrees (360/16), from X to Y.
6. Import the same profile. This time, since the work coordinates have changed, the profile is 45 degrees up from the original profile, and X is rotated 22.5 degrees toward Y.
At that point, I kept repeating steps 5 and 6, until I got all of the way around to the zero point. By that time, I had 16 profiles along that 7" circle, and through the course of the circle they had rotated 180 degrees.
Once I got all of the profiles in place, I used them to define the swept solid. I think that the UG command is "Swept solid using curve", or something like that. Initially, I tried profiles at every 90 degrees and 60 degrees, but each of those would make the swept mobius freak out.
Once I got this procedure down, it was about an hour of CAD busywork to make the mobius strip become a solid. I found this out the hard way, since Woodie reviewed my design about 5-6 times, and would ask for tweaks here and there. Each time, I had to create a new profile and import each of the 16 copies at their unique locations and angles. For some reason, the profile would not keep its parametric ability once it was imported into the mobius file.
There... if you followed that, you deserve a cookie.
Andy
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