Array with set start and end points and variable spacing in between

[Anonymous]

I need to create an array of rods going through a wooden plank, in elevation.

1.  the start and end rods must always be 100mm from the ends of the plank

2.  when you stretch the array out, it must automatically space the rods equally between a minimum of 300mm and a maximum of 650mm spacing

Please help.

Thanks

[Libbya]

Post the block.

[Anonymous]

Here is a quick dwg

[Libbya · Accepted solution]

Here's a working block.  The way it works is that there is a visibility for each additional rod.  A double lookup switches to the next visibility state when the distance gets long enough.  If you want the change to occur at a different length, you can change the range values on the double-lookup.

[Anonymous]

You da real MVP!

Thank you very much for this!  I will take some time today to decipher the method so that I can apply it in future.

Thank you very much for your help.

[Imui]

Hi,
What happened with "The whole structure must be able to stretch smaller to 600mm and larger to 2700mm"

[Anonymous]

If you open the block in regular model space, it has only one stretch grip, and as you stretch it the timber plank stretches up to a max of 2.7 and the rods increase as per the original spec.

[Libbya · Accepted solution]

I found one small error.  I used an end parenthesis instead of an end bracket for the range value at 2700 on the double lookup input table.  Because of that it was reverting to the 2-rod state when stretched all the way to its limit at 2700.  Here's an updated version.  

[Libbya]

I'd mention one other thing.  Your specification of varying the 'array' between 350-650mm can't work for the overall range between 650-700.  In that range, the length is too long for a single space and too short to be divided into two. 

[Anonymous]

That is fine, I understand and that doesn't affect the design.

[Anonymous]

WOW I don't know how to thank you for this! Thank you

[Anonymous]

This looks like  very helpful technic.  I need to create a glass balustrade with the post not exceeding 1200mm centre to centre but still array and divide evenly.  I tried to deconstruct your block but could not work out how the visibility and lookup is controlled by the stretch action.  Are there constraints somewhere that is hidden away?

[j.palmeL29YX · Accepted solution]

Attached another proposal. This without the "600-2700 limitation".

cadder

[KDaly23]

I know this is a really old post but is there anyway someone could explain how this block works? Ive been messing with it and for the life of me cant understand it. 

Trying to create something that works just like this!

[Libbya]

Which block?

The block I posted works using a double lookup.  One table has the linear parameter added with range values to determine the row of the table.  The other table switches the visibility state based on the row determined by the first table.  

The block that jpalme posted uses a nested array (created using the ARRAY command) with formulas inserted into the array properties. 

[j.palmeL29YX · Accepted solution]

The attached dwg shows two examples how you can solve such issues. It uses constraint parameters and formulas for the properties of the array (have a look in the Parameter Manager). 

[KDaly23]

Yeah that second block you attatched there @j.palmeL29YX is what im looking for. 

I think im stuck on the array part. 

The constraint parameters make sense to me I believe but im not sure Im following on how to set up the array. Notably there is that gray dimension constraint that appears when you click on it (noted as: Rotated Dimension (dynamic) )

[KDaly23]

At a very basic level this is what I am trying to achieve. 

Thanks for all the help! Im trying my best to learn how this works!!!

[j.palmeL29YX]

---

@KDaly23 wrote:

there is that gray dimension constraint ... (noted as: Rotated Dimension (dynamic) )

---

This dimension was created with the DCLINEAR command. It is the difference between the startpoint of the Horizontal Constraint Parameter (Length-Overall) and the startpoint of the array. You need it to get (to calculate) the correct current length of the array's length. If your array begins at the startpoint of the "length_overall" you don't need it. Also you would not need the User Parameter "Length" and in the formulas for Number and Step you can substitute it by the Length_overall Parameter. 

If this answer doesnt help you wait plese until after the weekend, then I can show you a video what to do.

[KDaly23]

I think that makes sense. However a video would help a lot in seeing how to actually implement it.

No worries/rush on it, thank you so much for the help!