Calculate your material

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Catherine Griffin
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1 Calculate your material This guide will show you how to calculate your material for a 3V Geodesic dome. Written By: Eric Schimelpfenig 2017 sketchup.dozuki.com Page 1 of 8

2 INTRODUCTION The following steps will walk you through how to calculate your material for cutting your pipes. In our case we used off the shelf hubs and a spreadsheet that we baked up to make the cutting process really easy sketchup.dozuki.com Page 2 of 8

Step 1 Cutting Guide To make all of your cuts you need to calculate each cut in your dome. Every dome size and tessellation is different.

Follow along with this guide by downloading our SketchUp model of this dome here.

Most formulae for geodesic domes assume that you have a wire structure like this. The distance they calculate is from point to point.

3 Step 1 Cutting Guide To make all of your cuts you need to calculate each cut in your dome. Every dome size and tessellation is different. In the following steps we'll learn how you can easily calculate your pipe cuts for your dome. We even have a handy spreadsheet that will do all the hard math for you. Follow along with this guide by downloading our SketchUp model of this dome here. Step 2 Understanding the measurements From now on this instruction set is referring to a 3V geodome. Most formulae for geodesic domes assume that you have a wire structure like this. The distance they calculate is from point to point. The dome you're going to build will use hubs. When you insert the pipe into the hub, there a space between the end of the pipe and the theoretical intersection point dictated by the formula. To put more simply, hubs effectively make your pipes longer. If you don't account for this you will end up doing the math for a dome, and it will be larger than you anticipated sketchup.dozuki.com Page 3 of 8

This spreadsheet will allow you to calculate all of your cuts and material usage for any diameter 3V dome you'd like to

4 Step 3 Spreadsheet To help you figure out how to make all of your cuts we have created a spreadsheet that we used to build our domes. Get that spreadsheet here. This spreadsheet will allow you to calculate all of your cuts and material usage for any diameter 3V dome you'd like to build. This will let you easily figure out how many pipes, hubs and bolts you need. In the following steps we'll show you how to download and use our spreadsheet sketchup.dozuki.com Page 4 of 8

5 Step 4 Downloading the sheet Our example spreadsheet is not editable. To edit it you're going to need to copy it to your Google Drive account. To do that, open the sheet using this link: 3V Cut Sheet Go to "File" and click "Make a copy" This will put a copy of this spreadsheet into your Google Drive folder so you can edit it. You must be signed into your Google Account for this to work Once you do this you'll have your own copy that you can edit anyway you want. If you mess up formula in your sheet you can always come back here and make a new copy 2017 sketchup.dozuki.com Page 5 of 8

Step 5 The first number you're going to want to set is your diameter of your dome. This is the diameter around the base of the dome. Just punch in the number in feet and hit enter.

5" Step 6 Set dome count and waste Next we're going to set the number of domes you want to make, and the amount of waste you'll have. The amount of waste is a percentage.

6 Step 5 The first number you're going to want to set is your diameter of your dome. This is the diameter around the base of the dome. Just punch in the number in feet and hit enter. All entries should be decimal numbers. So if you wanted a ten and a half foot diameter dome you'd enter it as "10.5" Step 6 Set dome count and waste Next we're going to set the number of domes you want to make, and the amount of waste you'll have. The amount of waste is a percentage. This will take all hub, hardware, and pipe counts and add a little extra to your calculation. This way if you lose a few bolts, break a hub or miss cut a pipe you'll be covered. Enter your dome count as a whole number Enter your percentage waste as a whole number. Numbers from are acceptable sketchup.dozuki.com Page 6 of 8

7 Step 7 Set stock pipe size Next we need to set the length of pipe we'll be cutting. We used 10ft PVC pipe that was available at the hardware store. You can see our entered length is just shy of 1' at 119". We did this because some of the pipes have chipped ends, and this allows for your saw kerf if you're cuts are really close sketchup.dozuki.com Page 7 of 8

"Number of each length for one dome" tells you how many of each length you need. "Amount of pipe to order" tells you how many pipes you need for each individual length.

8 Step 8 Final Calculations Now that you have all of this information into your spreadsheet we can take a look at the cuts you need to make. Lengths A B and C correspond to the map that's below in the sheet. "Individual Lengths" tells you the length of each dome type you need. "Number of each length for one dome" tells you how many of each length you need. "Amount of pipe to order" tells you how many pipes you need for each individual length. "Yield per pipe" shows you how many pipes you'll get out of each length of pipe. "Waste per pipe" shows you how much waste you'll have in each pipe length. This can be a good one to pay attention to. Sometimes changing the size of your dome just a tiny bit can make it so you waste a lot less pipe (and save some money) This document was last generated on :22:26 PM sketchup.dozuki.com Page 8 of 8

Assembly Time: 4 hours for one person 2 hours for two people. These instructions can be downloaded at

Assembly Time: 4 hours for one person 2 hours for two people. These instructions can be downloaded at Large 51/2x12ft Dome Assembly Instructions You will need: A wrench or drill with a 7/16 socket for tightening the bolts Rubber coated knit gloves ($3 gloves at Walmart or any Hardware store) At least 15