smoke detector dynamic block

[victorctti]

hello again, today I have a very specific problem, I am developing a dynamic smoke detector block that has a square area of maximum 81m² with dimensions 9x9, this square/rectangle needs to be within a circle of 6.3m in ray. And apart from this rule of maximum area in a 9x9 square and being inside a circle of radius 6.3, the block itself can have any area and dimension that meets these rules. The problem is that I've already managed to make the rectangle with a different shape but that maintains the area using constraining because using constraining I can set its maximum and minimum value in order to respect the limit of the circle, but this maximum and minimum value become completely useless after changing the area and honestly the way things are maybe with vba I can get some results, but even using this tool I foresee great difficulties. If anyone could help me I would be most grateful.

[j.palmeL29YX]

Attached an attempt, where you find a rectangle inside of a circle.

In the property panel you can choose an area and the rectangle adjusts its dimension accordingly.
But:
Your text above is not completely to understand:
If you have a circle with a radius of 6.3, then you can never draw an inside rectangle with an area of 81. The largest rectangle can get an area of 79.38... with an edge length of 8.9095...
Or if you need urgently a 9x9 rectangle, then you need a circle of at least 6.364.... .
Or I misunderstand completely your issue ... (?)

Please clarify your request. 

[victorctti]

In reality, the dimensions and area are an exception generated by the safety standards of my country

[victorctti]

And look, I don't want to be boring, but could you show a video on how to do it? I have a previous version of AutoCAD and I can't open your file and if I convert the file it's broken and I can't see how it works.

[j.palmeL29YX]

First: The most important information for us - which AutoCAD version do you use? (A "previous version" doesn't help us to help you).

Next: Your image doesn't explain what you really want. Do you need only the three rectangles 8x10, 6x11 and 4x12? What is with the 9x9? And what is the circle for? If the circle has to touch the corners of the rectangles you would need three different radii:

area 48 -> r 6.326..

area 66 -> r 6.265..

area 80 -> r 6.403..

Do you want these three different circles? It is easy to implement that, but we must know if you need).
Tell us please how the block should work in use. Which values are important for you? The dimensions given in your picture are contradictory. 

[j.palmeL29YX · Accepted solution]

... could you show a video on how to do it? 

Your first post above I understood as follows: 

- you have a circle with a defined radius (your example 6.3)

- You need an inscribed rectangle inside the circle with  any (free to choose) area. The dimensions of the rectangle must be adjusted automatically. 

The following image shows my thoughts how I'd solve that: 

We must calculate the needed dimensions of the rectangle based on the known values for D and Area. 

The following video shows a way how to implement this in a dynamic block. 

A resulting dwg file (in ACAD 2007 format) is attached. 

In the meantime I (think to) know, you need some rectangles with discrete given dimensions. 

For these situation I will show a suggestion solution in a later video. 

[j.palmeL29YX]

An other interpretation of your issue: 

[timothy_crouse]

I find blocks like these interesting and frustrating at the same time.  I assume (we all know what that does  :)) this block will be used in construction drawings plan sets.  Take note that there are two things that can slow plan set down as they grow in size.  The use of arrays and numerous blocks that require math to keep them in-tact.    A couple examples.  A data center with arrays of rows of cabinets can get laggy but when you blow the arrays away and use groups or blocks of cabinet groups the drawing performance increases.

Regarding parametric blocks.  I once had a D-Size sheet with 14 wall section details.  The details included steel beam blocks constructed from many parametric and geometric constraints.  I eventually had to explode the details and re-insert them as a new re-defined block without all the constraints due to the drastic screen lag that was occurring.  

I think if you keep an eye on the drawing size and try to keep the memory footprint small you will have no problem.  I realize that is a general comment.

That my 2 cents even though you didn't ask.  I hope it saves you some trouble.

Best Regards

-Tim C.