Calculating Conduit Elbow lengths?

Revit
1

Curious why the “Conduit Length” parameter is different from the total lengths of an elbow’s curves.

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Any insights?

PS: total lengths of an elbow’s curves agrees with what gets calculated in Revit’s Conduit Run length.

3

You will need to use the Element.Location node to get the cures and isCurve lengths. Then do the Math.Sum. The script I have here is to give me the selected conduit and conduit fitting total length.

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4

I did similar.

But what the heck is the “Conduit Length” parameter in Revit for?

BTW: To round your numbers to 1/16" use:
Math.Round(n*16*12,0)/(16*12);

5

But when I divided the “Conduit Length” parameter values by 3.2366, I got the geometry curve sums. WTF?

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6

Assuming you’re using the OOTB Conduit PVC Elbow:

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Conduit Length controls the straightline component of the fitting.

The conduit length parameter reports in inches, but curve.length node reports in feet. Try multiplying the straight line lengths by 12, you’ll match up to the conduit length parameter.

7

So I my question is what are you trying to accomplish? The script I utilize is for fabrication efforts and for general inquiry. This is the information I am most interested in. This again depends on what I have selected. A entire run or just a section of pipe that will be fabricated. The Move Distances get copied to the clipboard so I can past that into the move command.

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9

We have accomplished getting the elbow lengths with Dynamo. But my question was what the hell is the “Conduit Length” read-only parameter on elbows, and why is it 3.2366542 times the actual length in my example?

Answer via Robert_Younger: The parameter is in inches and it is only used for the straight part of the elbow.

size_lookup(Conduit Size Lookup, "CLgt", 1.25 * Nominal Diameter + 1 95/256", Nominal Diameter)

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New question: Why the hell do we have an inches unit parameter when Revit uses feet as its internal unit?

10

Sounds like a units issue (1m = 3.2 ft)

11

New question: Why the hell do we have an inches unit parameter when Revit uses feet as its internal unit?

  • Pipe Size / Duct Size are parameter types that generally report back in a smaller unit size for convenience. You’ll see the disparity most easily in something like an Air Terminal family, the faceplate will measure in-family in feet, but the duct connector in inches.

  • Retrieving parameter data (GetParameterByName) is a different workflow than extracting geometry values (Curve.Length). Retrieving parameter data will give you values that match your project units. Geometry information generated in Dynamo will use Dynamo’s internal units (which I believe are always feet in this case, metric users correct me if I’m wrong?)

12

Thank you for the concept.
Any ideas why “CW.Element.Location” doesn’t work?

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I use this version of CW and it works on my end.
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15

We have also played around using dynamo to create conduit lengths based upon a conduit ID. I have found adding a Length parameter to Conduit Fittings to match that of the Conduit. Allows for a easier way to accomplish this. The parameter in our fitting look like this.
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16

Check this Post: about similar topic for pipe fittings [Compliance with POMI method of measurement]

This Premise may also help :small_red_triangle_down: :small_red_triangle_down:
Fitting Length VOL5.dyn (227.9 KB)

Also check this amazing topic by Jeremy from the Building Coder [ contains code snippets in Python and C# ]

https://thebuildingcoder.typepad.com/blog/2024/09/mep-cable-tray-bend-and-tee-analysis-1.html