Creating a pattern of slightly varying but similar features can be very time consuming.
Examples
- Concentric circular features
- Holes descending in size
- Patterns with progressively increasing spacing
My favorite solution would be to add a function or special variable to the parameter formula system. The function would return the index within a pattern. When the pattern instances were calculated, each instance would get a different index value, and any parameter involving the index function would vary. For the case of nested patterns, it might be helpful if the index function took a parameter to specify which pattern's index to return. For example index(0) would return the index for the lowest level, most recent, pattern, index(1) would return the index within the parent pattern and so on. If index were called from outside a pattern it would return 0, so everything should always work.
So if I wanted 5 holes from 5 to 10 mm, I would sketch a circle and dimension it as "5 mm + index(0) * 1 mm", extrude it and pattern it 5 times. If I wanted varying spacing, I would use the index function in the spacing field of the pattern. In theory you could even use the index function in the quantity field of a sub pattern.
I can imagine that this might be quite a tall order, I have no idea about the internals of Inventor. But on the surface of it, it would be a change with a small footprint and an incredible amount of flexibility. Perhaps there is some other way to reach the same goal. Either way, I hope it's something you'll consider.
