Rods, Take-outs and Weights

Once the load-bearing component is selected, the software has to turn it into a buildable assembly: a rod of a given length and thread size, a stack of parts with known dimensions, and a weight. This article covers that stage.

Take-out

The take-out of a part is the dimension it contributes to the overall length of the assembly. The take-out of the assembly is the sum of its parts.

The software computes it in two variants:

• Without rod — used as the basis for working out how much rod is needed
• With minimum rod — the shortest the assembly can physically be

The Takeout List, on the second tab of the support datasheet, shows the breakdown part by part. It is the quickest way to see where the length of an assembly is going.

Rod length

The rod makes up the difference between the space available and the space the parts occupy:

The available height comes from the elevations you entered. The allowances cover the project’s minimum extra length, the engagement needed at each threaded connection, and a few part-specific additions.

If you have not entered elevations, the software cannot compute the available height and instead returns a nominal length based on the take-out and the thread size. It is a placeholder for a drawing, not a construction dimension.

Minimum rod length

Every thread size has a minimum manufacturable length, rising from 200 mm for small metrics to 500 mm for the largest. A short calculated length is raised to that minimum, which means the assembly ends up slightly longer than the geometry required.

An impossible geometry

If the structure elevation is below the pipe elevation, the software returns a rod length of zero. This is not a result — it means the elevations are the wrong way round or one of them is wrong. Check the input.

Splitting a rod

Above a threshold length the rod is supplied in sections joined by couplings, because a very long single rod is impractical to transport and install.

The process repeats until the remainder is short enough: a section is taken off, and the rest is reconsidered. Each split adds a coupling and two hex nuts to the bill of materials. On a double support, quantities double.

The last section is subject to the same minimum length rule as any rod, so a short remainder is raised to the minimum — again making the finished assembly slightly longer than calculated.

Turnbuckles

Turnbuckles are a practical solution for ease of installation and adjustment of long rigid hangers. Below a minimum rod length a turnbuckle does not fit, so short assemblies do not get one.

If you try to set a rigid hanger with a turnbuckle when the installation length is too short, the software will direct you to use a single rod solution. However, if you select a rigid hanger without a turnbuckle with a long installation length, it does not automatically select a turnbuckle for you. Instead, it will split rods with couplings as explained in the previous paragraph.

Weights

The software reports weights per part and per support.

The provided weights are the catalogue values corrected for the actual dimensions of the assemblies. Where a part has been made longer, taller or heavier-duty than standard, the real weight reflects it.

For rods, the weight is simply the linear weight of the thread size times the length.

The assembly weight is the sum of the real weights times their quantities, plus accessories and additional parts where the project includes them.

One case where weight becomes a load

Normally weight is an output. There is one exception: when the project’s load calculation mode is set to include accessories, the accessory weight is added to the operating load before the model is selected.

This is worth knowing because it changes the selection. The same support, with the same pipe load, may come out a size larger under that setting. If you are comparing two projects and the selections differ, check this setting first.

The bill of materials

Before the list is issued, identical parts are grouped and their quantities summed. Two parts count as identical when they share a reference, the same custom dimensions and the same special data.

Rods of different lengths do not group, because the length is part of the special data. A support with three rod sections of different lengths shows three lines, not one line with quantity three. That is intentional — they are different parts.