LISP TO MAKE Y BRANCH DUCTING

[smallƑish]

Is that possible to do it by automated process by lisp ?

my usual drawing  process added as step by step as dwg file attached the same,.

[pendean]

May I ask why you would not create once then use often a BLOCK (or possibly a dynamic block) for this very critical has-parameters-that-must-be-met-based-on-duct-sizing portion?

[smallƑish]

Most of the lines are drawn by the result of equations, Hence making a dynamic block will also require calculations. to adjust the stretch points.

[pendean]

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@smallƑish wrote:

Most of the lines are drawn by the result of equations, Hence making a dynamic block will also require calculations. to adjust the stretch points.

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Exactly, since precision and accuracy is important, as you cannot build just any duct connection in the real world and expect it to work, we all do that all day long all the time.

Is asking for a LISP from others without providing these limitations and parameters etc help you draft accurately for a contractor beneficial to you?

And if I may ask, would a version of AutoCAD like MEP or MECH be better at creating "concept" drawings if that is all you wish to create?

[smallƑish]

I believe, I have explained all those calculation and user given datas, are included in the same DWG file by step by step for easy understanding.

[Kent1Cooper]

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@smallƑish wrote:

I believe, I have explained all those calculation and user given datas, are included in the same DWG file by step by step for easy understanding.

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Sort of....

I think the red line near the top of the sequence should be drawn after Filleting lines 2 & 3 with the radius of 1/4 of the branch duct width.  It happens in the example that the end of line 2 is in the right place to begin with, but surely that won't always be the case.

I don't think you need step 4.  Just Fillet lines 2 & 3, then Offset the resulting Arc by the branch duct width.  There's no need to mark out that position and then Fillet it with the other side of the branch duct.  You might need to Trim or Extend the other side of the branch duct to the larger Arc, but that's no more work than marking the location with a Line that you then need to Erase.

Lower down you talk about Offsetting the red line, but it isn't red [any more?], so it's not really clear whether you mean the one that was originally red, but I think you mean the new one that's yellow.

If the duct divider point is supposed to be at the calculated distance to the right of line 2, it's close, but not the same.  Is that supposed to be rounded to the nearest multiple of some value?

Step 8 talks about the subduct length, but there's no indication of what that is.  Should that be subduct width?  And I assume the "redline length" that should be subtracted from it should be the yellow line length.

[Sea-Haven]

My $0.05 I would drag over in sequence this gets all the lines in order, the perp widths and so on then draw the shape.

[smallƑish]

A similar code and its working GIF are attached for reference (But it is TEE connection, not a YEE) . found the code from the internet only, No idea about the writer.

[leeminardi]

Here's an approach that uses the Parametric features of AutoCAD.  Could you  add some clarification to Steps 8 and 9 as they were not clear to me so I did not include them?

[smallƑish]

There was a confusing factor in the explanation of steps 8 and 9, so  Modified steps 8 and 9 with 2 additional explanations Steps 8A,8B, 9A, and 9B. Please find attached dwg.

[smallƑish]

Added answers in Blue.

Sort of....

I think the red line near the top of the sequence should be drawn after Filleting lines 2 & 3 with the radius of 1/4 of the branch duct width.  It happens in the example that the end of line 2 is in the right place to begin with, but surely that won't always be the case.

Yes, it differs depending situation.

I don't think you need step 4.  Just Fillet lines 2 & 3, then Offset the resulting Arc by the branch duct width.  There's no need to mark out that position and then Fillet it with the other side of the branch duct.  You might need to Trim or Extend the other side of the branch duct to the larger Arc, but that's no more work than marking the location with a Line that you then need to Erase.

Yes, I have explained it for easy understanding.

Lower down you talk about Offsetting the red line, but it isn't red [any more?], so it's not really clear whether you mean the one that was originally red, but I think you mean the new one that's yellow.

Yes, that was a mistake in the color. Supposed to be red. Updated the file. 

If the duct divider point is supposed to be at the calculated distance to the right of line 2, it's close, but not the same.  Is that supposed to be rounded to the nearest multiple of some value?

Yes, rounding off to the very next could be preferable.

Step 8 talks about the subduct length, but there's no indication of what that is.  Should that be subduct width?  And I assume the "redline length" that should be subtracted from it should be the yellow line length.

Explanation updated with 8A,8B,9A,9B

[leeminardi]

Here's a revised version using parametric constraints including the clarification in steps 8A and 9A.  I've done limited tesing but it appears to work satisfactorily for reasonable values for the various paramters!  Try it out.

[smallƑish]

I respect your hard work. modifying your file with the required drafting task is getting very complicated for me, Maybe I'm very now for the specialization part.

[smallƑish]

Found the branch is working properly (3rd my request part in GIF) with the existing code. only the Sub duct line is balanced. Is that possible to automate? 
Working GIF and Lisps are attached for better understanding.