# Make a Geodesic Dome From Steel Tubing

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Here on the Kibbutz, we are celebrating 50 years since the founding. We have a group that shares a workspace for woodworking and metalworking. We decided to donate our time and build.. a Geodesic Dome!

Interested in making a Geodesic Dome Greenhouse? https://amzn.to/2Aiqg4i

I also highly recommend this book about making domes cheaply: https://amzn.to/2n7CXFC

I'm not going to give exact measurements here since it is likely that you'll want to build a dome of your own size. There are all sorts of dome calculators online. We used this one:

http://www.domerama.com/calculators/3v-geodesic-do...

## Step 1: Dome Types

There are different types of domes and we are making one of the simpler ones: 3V 3/8.

## Step 2: Cut Your Tubing to Length and Crush the Ends

We cut the two lengths of tubing necessary and crushed the ends using a hydraulic press.

## Step 3: Drill Holes

You'll have to drill many, many holes.

## Step 4: Drill Away!

If you have a drill press this will go much faster. We didn't, but we did have a drill mounted to a stand, which did help make this go faster. First we drilled small pilot holes and then we drilled our the final size. We are using M8 bolts and the holes fit these semi-loosely. Don't push down hard as you will likely snap or dull your bit. Let the bit do the work.

## Step 5: Drilling All Done

As you can see the ends are pointy and we can't have kids slicing open their feet while climbing on this.

## Step 6: Use a Grinder to Make the Pointy Ends Rounded

We cut off the ends of the pointy bits and rounded everything off. No we didn't do this safely and yes I've gotten a lot of shit about this all around the internet. I'm ok with that as it's a good learning experience!

## Step 8: Bend the Ends to 15-20 Degrees

Each end was bent so that when we bolt them together they will lay more or less flat.

## Step 10: Lay the Circle Out on the Ground.

You'll get a feel for how big it is going to be. Ours was 6m in diameter, and 2.5m in height.

## Step 11: Build the Top First

We built the top first and worked our way down.

## Step 13: Rest of the Owl

And there you go! You now have an awesome Geodesic Dome!

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## 15 Discussions

Looks so cool. I remember my childhood playground having one of those. Was it expensive to build?

My dad (a "mid-century modern" architect and follower of Buckminster Fuller) had my uncle (a contractor) build us kids one of these in the 1960s. We were the coolest kids in the neighborhood! They just had to teach us to be careful of the bolts, since they could scratch us or tear our clothes. I'm not sure if Dad and Uncle Jack ever figured out how to deal with those, but we still loved it. We made it into a tent with old sheets and read for hours inside. My mom probably had hoped I would get some exercise using it, but what can I say? I was a bookworm. Congrats on giving your kids something unique to play on!

Ya, those connections are the thing I worry the most about. They can definitely give a kid a good scratch. But, well, what is a childhood without some good scars?

Unlike drilling wood, high pressure is required to allow the bit to bite into the metal. Light pressure allows the cutting edge to slide over the metal, with high friction, heat, and rapid dulling of the bit. With common (low carbon) steels, and aluminum, curley-Q helixes of material will be produced at proper feed rate. Also, note that drill RPM goes down as diameter goes up. Slower (400-600) often makes the hole faster. For 1/8th inch pilot holes, full speed {1200-1800 RPM) and lighter pressure as you come through the back side will minimize breakage. Lastly, cutting oil will prolong bit life and allow higher speeds, typically holes larger than 5/16ths.

I wish I had known this at the beginning of the project. I don't have much experience with working with metal and drilling the holes was a huge headache.

How do you determine the size of the EMT conduit as the dome plans increases in size? Does the covering choice determine the safe conduit size and if so how do I calculate the Min. safe cost. Thanks