New Dome Designs

[Scott J Becker]

After 40 years of dabbling, I have some designs to contribute.

I've written a program to calculate and visualize new designs. The input is data arrays that define the strut endpoints with angle up, angle of rotation, and how many times to repeat around the circle. It's a bit tedious but you always have all points on a sphere, and exactly a hemisphere with a flat bottom.

The result is absolute freedom to divide a hemisphere any way you can imagine. I've worked up some designs that are not based on platonic solids and not based on the icosahedron.

The first group is based on the octahedron and includes my take on 2F - 5F tessellations (with 2-5 unique strut lengths). I'm unsure if any match any standard designs as I worked in a vacuum. I've included three other designs that do not use standard tessellation, but add more choices of the number of base triangles.

The second group are variations based on simply starting with a hexagon on top instead of a pentagon that all icosahedron based domes have. The unique domes have a pattern the is repeated six times around the circumference because of the top hexagon.

The last group is the same but has a heptagon top (7 sided).

These non-platonic, odd-tessellated designs have higher numbers of unique strut lengths. But they also have connector rows that are much more even in spacing and height from the ground, as well as more even angular height spacing between rows.

One of my design goals was to have variations for a shallow dome to use as a roof on buildings with straight walls.

Another trick is a few variations that allow building multiple domes adjacent to each other, connected by perfectly vertical archways. (Stacked, for lack of a better word.)

I've placed all the designs I'm sharing in the public domain for all to use freely. I can also quickly create more custom designs by request to satisfy specific requirements.

  FB_IMG_1714568624847.jpg

  FB_IMG_1714298877369.jpg

  FB_IMG_1714298892033.jpg

  FB_IMG_1714298846923.jpg

  FB_IMG_1714298720628.jpg

  Domes, Custom.pdf

  Dome_Roof.pdf

[Dx G]

Hi Scott,

 Generous of you to make that available.   I assume you are referring to spherical coordinates? I see an advantage of achieving a flat truncation, since this is often a speed bump with certain polyhedra.  As to other advantages, a few questions:

1) It would be helpful to have all angles - face, axial, central and dihedral - for each design.  In addition, data on diameter vs elevation of various horizontal "cuts" through the structure are also useful to builders along with volume and surface areas.

2) Having designs with the smallest possible number of strut and panel sizes is a plus.  Having some routine which sorts through options and points to designs with minimal variation in components is also useful.

3) What language or system is the calculator written in?

thx

Dx G

[Scott J Becker]

The numbers in the PDF are strut factors. I think the angles can be calculated from them using trig. It's been a long time since I did that. I can probably add that to the program.

I'm not familiar with those terms. I did this in a vacuum, I've found that I tend to be more creative when I don't study what everyone else is doing. Of course I don't mind learning if it makes it more useful to people.

I've labeled the strut factors and put total counts on the right so for each design you can see how clean or messy the build is.

I also put the longest strut at the bottom so you can quickly determine the diameter that can be built from 8' lumber, etc.

It also exports a CAD file (DXF) with struts on layer 1 and triangle faces on layer 2. So that would allow the triangle calculations.

The calculator is written in "Processing" which uses Java. It mimics the Arduino IDE and is designed to generate interactive graphical displays.

    Scott

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[Scott J Becker]

Here's a DXF for one of them:

[NASEHI]

Hi, my dear friend
I translate with google
Tell me how to calculate a gneid with a diameter of 9 meters according to your method
I am a retired teacher
And I want to spend my time doing this
Thank you for the advice you will give.

‫‪Dx G‬‏ <‪yipp...@gmail.com‬‏> در تاریخ پنجشنبه ۲ مه ۲۰۲۴ ساعت ۱:۴۰ نوشت:‬

[Scott J Becker]

First you divide your diameter by 2 to get the radius:

9 meters diameter / 2 = 4.5 meters radius.

Then you multiply the radius by each Strut Factor, in the design you want to build:

0.3640528 X 4.5 meters = 1.6382 meters (or 1638.2 mm)

The number to the right is the count of struts needed.

As you look at the strut list, the first is starting at ground level.
The ones with  ---- next to them are horizontal.
////\\\\ and /\/\/\/\ are slanted.
And  ||||  are vertical.

I hope this helps.

    Scott

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[Paul Kranz]

Scott: I am a 47-year dome dabbler myself. I have often thought about a business that helps people understand the dome option to building.

Intuitively, this would be best communicated by the number of triangles to enclose whatever the space required.

You have a spreadsheet (attached) which tells you the most economical way (fewest triangles) to enclose the space and quote the prospective client a price based upon the number of triangles.

To keep things simple, figures should be based upon no triangle having an edge of greater than 8-feet to accommodate 2 X 4's and plywood standard offerings for minimal waste and lightness.

You could also offer a high and low spherical profile options if the would-be customer needed more height or a second floor or with or without riser walls.

Part of the sale would be your digital generation of what the dome would look like (I would make a model myself).

Then after you made the sale, you could worry about how to make each triangle with the tool you've come up with.

Paul sends...

[Scott J Becker]

Cool idea. I've been focusing on the strut factors but recently added triangle generation.

The main reason was for superior visuals, but now I can add a triangle count and even

triangle details. I do have CAD output.

I haven't generated greater than hemisphere domes yet but I can.

    Scott

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