Array parameter inside dynamic block

[lukasz.sztybrych]

Hello All
I have interesting challenge for all expert on this forum.
Have dynamic block (perforated panel) with holes inside.
Need to make chained array always in the centre of the panel.
Another words I need this little 45x45 squares to be always in the middle of big polyline (unfolded panel)
Problem I have is to centralize array into another object. Preferably without using LISP

[Libbya]

As you've probably noticed, the problem with keeping it centered is that the array switches between an even number and an odd number of items.  For the even number, the center is the midpoint between two objects and for the odd number it is the center of the middle object.  That means that each time a single item is added, the array needs to shift.  This can be accomplished using a double lookup or block properties table, but only for a limited number of arrayed items as you need to define the array position for each number of arrayed items.  Is there a workable limit?

[Libbya]

There is another option if you can have an increment for the main stretch parameters that is equal to the column offset.  Let me know if an increment is workable and I'll show you how.  

[lukasz.sztybrych]

Hello
Just to clarify what I want to achieve. While stretching object, chained array needs to stay always in centre

Distance A=B
Distance C=D

Distance B≠ C

Distance A≠ D

I know how to do it in lookup, but I want to apply this block for different panels (having different perforation) therefore I would like to find a way to make it as general as possible.
There're limits 1300mmW x 3000mmH and creating lookup block with increments of 50mm is a hassle

[Libbya]

It was clear that you wanted A=B, C=D.  

If you cannot set the main governing parameters to an increment that matches the column offset, then I think you will find that you are relegated to either using (2) double lookups (one for horiz, one for vert, and yup, it would be a hassle) or abandoning the concept.  The bright side is that you'd only need to set up the lookup tables once and then it would all be automatic.  

[Libbya]

Here's a step-by-step screencast that shows how to do it.  Personally I think that the hassle of filling out the double lookup tables is relatively insignificant.  Of the 25 minutes that it took to make the screencast I probably spent 2 minutes filling out the tables.  Granted I only filled out the height to 1/2 the table and the width to 1/4 the table so it would take an additional ~5 minutes to fully complete the tables.  That's not a big time commitment compared to the rest of it.  Anyway, hope that helps.  Let me know if you get stuck.