1. Start with a simple revolution. I put the large sphere centered on the origin to simplify later feature creation.
2. The key to my solution is a "rectangular" array along a path taking advantage of a rather obscure option to orient the feature in the direction of the path. I will make copies of the original revolution along a path. The yellow construction lines determine the desired positions of the copies. I then construct a path to tie them together. The distance along the path between each position must be identical. The angle that the path intersects the positions determines the angle of the copies. The start point of the path relative to the original revolution is somewhat arbitrary but must be maintained for each copy.
3. The rectangular pattern command uses the sketch as the direction. Notice the orientation is also set to Direction1. The spacing between instances is set to the sum of the curve arc length and straight segment length that comprise the path between the first and second occurrence. To understand what is happening, imagine the original revolution feature sweeping along the path as if it was on a guide rail. Dropping off a copy of itself each time it passes the specified distance.Â
4. The spheres of the third occurrence are hidden by the first and second occurrence. So all we see of it is the center connecting link.
5. Lastly I add a simple circular array about the X Axis to finish the model. I had to select both the original revolution and the rectangular array as source features for the circular array.
This is not a very efficient solution for this particular model but I use this command quite frequently when modeling attachment chain for packaging equipment. In those cases the path is just the centerline of the chain around the sprockets but the methodology is the same. Here the chain pitch is ridiculously long and the links are turned sideways.
I want to add that the path sketch does not have to be smooth. It can be comprised of simple line segments:
I would never understand why people love to complicate things when they could be very simple. To quote Leonardo, who said this 500 years ago: "Simplicity is the ultimate sophistication"
I believe you have missed the point of this challenge. The only goal is to create the model with the least number of features. The results are often very convoluted and complicated.
I also came up with a simple and efficient solution with 4 features.
Most everybody else did too.
It won't win and more importantly nobody will learn anything new.
The benefit of these challenges is we often learn new ways of doing things that do produce simpler and more efficient models when applied in the real world. Sometimes even learning how to do things that we didn't even think were possible before.
In a Feature-Based CAD software the challenge is to create a model efficiently using features which will not fell apart when go back and edit any dimension. It is NEVER about the least number of features. It is just the opposite. You should have a simple sketch whenever possible and use the features to define your model completely, not with hard to manage sketches which consumes lots of time to create and they are very hard to edit. Inventor is not the greatest software, but it is powerful enough once you correctly understand the principle of solid modeling.Â
As Bob said "you have missed the point of this challenge".
Your advice for more features and simple sketches is how real models should be made. This is a discussion for puzzles and riddles.
I find the main advantage of these puzzles to be the thinking and planning process. A side effect is learning new tools, and obscure functions for well known tools.
Why would anyone assemble a jig saw puzzle? Total waste of time when they can just look at the pretty picture on the box. But for people that enjoy puzzles it's an enjoyable activity.
Bogdan M wrote:
First try. Three revolves and I patterned two of them.
First revolve.
Second revolve and pattern.
Third revolve and pattern
Bogdan M also wrote:
Second try.
Two features, one body.
First revolve
Second revolve
Pattern the second revolve
He also wrote:
I used the sketch dimensions for the pattern. As I said in my solution post, the pattern is dimension table-driven.
How was done:
First feature:
- simple revolve of the central part.
Second feature:
I hope this will clarify more who was done.
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