Is this possible for a Dynamic Block? Connected Rectangles

[david.robsonU3BUN]

Hi Everyone,

I've looked at dynamic blocks in the past (mostly doing the usual tutorials creating dynamic door blocks etc) but have never found myself in a position where I'd need to use them frequently. Until now....

I'm producing a lot of 'frame' arrangements that are based around standard components. Previously, I've been using the array command to create the frames at a set spacing, and then manually adding the end frame afterwards. This works fine for straight line arrangements, but for curves can get a bit more involved in checking the spacings (and will usually involve drawing them in by hand afterwards)

If I know the amount of range of rotation for each connector, along with the maximum/minimum extension length for each rods, could this be done automatically with a dynamic block? Maybe even to the point of 'tracing' what would have been the array curve with your cursor to create the end arrangement?

I've attached a simplified file to try and help visualize what I'm trying to do - any pointers as to where I should even begin with this would be much appreciated! 

[j.palmeL29YX]

First I try to understand what you want to achieve. One of my questions: What is "the closest constrained length"? 

Here two examples: 

>>Video<< 

In the lower example the end cap overlaps the last element of the array. I don't believe that this is what you want. 

In the upper example the last array instance disappears in the moment when the endcap will touch it. 

But for both variants I'm not sure if I'm on the right way ... 

[david.robsonU3BUN]

The upper example is definitely closer - the connectors themselves have a maximum length of 1.2 and a minimum of 0.4, so after they reach the 1.2 another would be added, and if it's less than 0.4 would disappear altogether 

[j.palmeL29YX]

Here my next attempt:  

I did not yet find a solution 😞 how to suppress the visibility of the right most segment automatically when the length of the connector is smaller than 0.4. My suggestion: manually switch its visibility on and off as you need. (Well, you will not know exactly when the value 0.4 is reached, but I hope this is not an urgent request). 

[j.palmeL29YX]

First: I hoped to read an answer or a commentary to my suggestion (post #4) how to handle the linear array. 

But regardless of that:
I don't understand your both "arc" sketches.
As I read the left: 

- The (mid)point (0) of the rectangle is constrained to the arc, okay.
- The point (1) of the rectangle is constrained to the lower connector (2). But in which distance?
- The upper connector doesn't meet neither the left nor the right point of the both upper points on the rectangle. ???

The right-hand sketch:

- I understand how the connector(s) have to meet the rectangle(s).
But:
- you have drawn a connector length of about 1.02550991 😉 . Didn't you want a length of 1.2, only the last connector may be smaller?
- Do you urgently need the angle of 90° between the rectangle and the connector? If so, you will ever get an angle between the symmetry line of the rectangle and the line to the center of the arc. In the shown example 5.0198..°. Its value depends on the length of the connector and the radius of the arc. 

What do you really want to achieve?
A suggestion which makes more sense for me, if the 90° between rectangle and connector are not urgently necessary. I could image a geometry as shown here:

>>Video<<

You can change the radius of the arc and also the length of the connector (if needed).
This is not a finally solution of your problem, it is only a first step for me and I hope your answer will help me to understand what you want to get.