# Full Version: looking for some advice on creating a triangulated tower

From: metric tensor (METRIC_TENSOR) [#1]
19 Oct 2017
To: ALL

I created this triangulated tower in OpenSCAD, I am wondering how to best go about it in MOI. It will the spine for a spacecraft I am designing. The triangulation in the image is not quite correct as the triangles should meet on the outside of the cylinder wall, not the middle.

Thanks!

Image Attachments:
spine.PNG

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From: bemfarmer [#2]
20 Oct 2017
To: ALL

Consider the large central tube to be divided into 3 arcs, 1/3rd the circumference each, and, in a sense, to be equivalent to 3 of the smaller tubes.

A module consists of 2 of the smaller tubes, with the 3rd tube the central 1/3rd.
Each pair of tubes has a zigzag bent metal tube welded between them, for a total of 3 zigzag tubes.
Place 3 modules in a hexagon arrangement, rejoining the center1/3 arc sections, and add 3 more zigzag tubes between adjoining modules.

Instead, one module, with a 4th zigzag tube hanging to one side at the hex angle, can be circular arrayed with 3 copies.

https://www.dxengineering.com/parts/tow-ame25-b3?seid=dxese1&cm_mmc=pla-google-_-shopping-_-dxese1-_-american-tower-company&gclid=CjwKCAjwmqHPBRBQEiwAOvbR84OqvR3y3VfEc4VSQNJk4njGJ1xbLMwu2SO4X3HHlPqw4rz74OxHHxoC8QYQAvD_BwE

Engineering analysis of strength is something else.

- Brian

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From: Michael Gibson [#3]
20 Oct 2017
To: ALL

Hi metric tensor, do the triangles follow a specific algorithm for how they're supposed to be arranged? Like at a certain angle or something like that?

For making the long vertical cylinders, I'd probably draw a larger circle in the middle, then a smaller circle off to the side and use Transform > Array > Circular to copy it, then extrude those up.

For the triangles if you can get points placed where the triangles are supposed to go, you could then draw lines between them, and when you have a big set of lines you can draw a circle down on the xy plane away from them, then select the circle and use Construct > Sweep and select all the lines as the rail curves and that will make tubes around all the lines.

It looks like a repeating pattern so you can probably make one layer of the triangle tubes and then replicate it using Transform > Array > Dir.

- Michael

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From: Barry-H [#4]
20 Oct 2017
To: ALL

Hi,
I have attached a sample drawing that might help.
Basically start with the central tube and one perimeter tube create the triangular shape you want (extend lines to allow for trimming of triangular tubes to the main vertical tubes) draw a circle for the size of the struts then sweep the triangles.
Hope this helps.
Barry

Attachments:
Tower.zip

Image Attachments:
Tower.png

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From: metric tensor (METRIC_TENSOR) [#5]
20 Oct 2017
To: ALL

Thanks everyone, the education begins :)

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From: bemfarmer [#6]
20 Oct 2017
To: ALL

Assuming the same triangular pattern of struts, the perimeter struts will have to be longer than the struts connecting to the larger center tube.
This will be embarrassing when the astronauts weld or bolt in the wrong lengths:-)
Unless the robotic welders can tell the difference.
I'd like to see the engineering specs.
- B

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From: metric tensor (METRIC_TENSOR) [#7]
20 Oct 2017
To: ALL

Fortunately in my computer game you get the ship pre-assembled. The FEA analysis will have to wait until I retire :)

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