Step 2: Making hubs

The hubs are the most difficult, time consuming, and critical part of the dome. The hub design consists of PVC tabs, bolted together to make a strong and flexible connector between the struts.

The use of schedule 40 pipe is important. Class 200 cannot handle the stress of holding the dome together without breaking. Schedule 40 is flexible enough to allow the dome to be built without bending precise angles, but strong enough to keep from breaking.

You need to make:
10      4-way hubs
6        5-way hubs
10      6-way hubs

You will need:
130    4" pieces of 1" schedule 40 PVC
130    couplings
26      1/4" x 2" hex-head bolts
26      1/4 hex nuts
52      1/4 washers

<p>I see the dome is 8' high but how wide is it?</p>
<p>16' as the radius id 8'</p>
<p>Another way to simplify this is to buy the hubs. That way you can make even more complex 4v and 5v geodesic models. We sell hubs at www.sonostarhub.com</p>
<p>yeah...for a freakin small fortune...lol</p>
<p>Hi, I live in India, and the guys here are having trouble understanding what type of PVC pipe you used to make the struts, Is is C-PVC, or E-PVC, could you please help me out here?</p>
<p>you list 30' of pvc but that's just for the hubs.</p><p>I'm calculating at least 270 feet for the struts.</p>
<p>What would You say about open dome?</p><p>http://www.polidomes.com/portfolio/mobile-event-center/</p>
<p>What would You say about open dome?</p><p>http://www.polidomes.com/portfolio/mobile-event-center/</p>
<p>What would You say about open dome?</p><p>http://www.polidomes.com/portfolio/mobile-event-center/</p>
do you think this idea could be used with metal conduit ?
<p>I know it's been a while since you posted, but I found a site you might like to look at. </p><p><a href="http://www.desertdomes.com/index.html" rel="nofollow">http://www.desertdomes.com/index.html</a></p><p>He has posted info about making a dome with conduit.</p>
cool!! thank you.
Yes...<br> <br> http://www.buylifetime.com/products/blt/pid-101310.aspx<br> <br> Of course it somewhat removes the DIY element... :)
<p>You could save money by making a coupling on the end of the pipe by heating the end then forcing another pipe lubed with something into the end about 1 inch or so. There's an ible' that teaches you how to do this but I don't remember the name.</p>
Just what I have been looking for. I want to construct a dome for 6 laying hens to be moved around the grassy yard. I am 88 but still garden and build things. Will cover it with chicken wire with tiewraps. I may use schedule 40 for the ground rounds and thin 200 for the rest struts.
Party dome, <a href="http://en.wikipedia.org/wiki/Buckminster_Fuller">Bucky</a> would be proud!<br> <br>
I want to build one for a movable chicken coop for about 6 laying hens for eggs to move around the grassy yard with a small roost and house for nest and comfort I am 88 but very active in the garden. Will tiewrap chicken wire for cover. Just what I was looking for. Thanks a lot.
Nice, but where's the door?
You could do this much simpler if instead of building hubs you just heat formed all the ends of the pipes flat and drilled a hole.
could you elaborate on this process further?
Take your pipe and heat the end above a flame or a heat gun, Do it outside for good ventilation. Right when the pipe starts to turn color, remove it from the heat and squish the end in a clamp or a vise for like 15 seconds, then dip it in cold water. That crimps it flat. Then, drill a hole through the flattened end. Now, instead of making brackets, all you need to do is line up the holes in the flattened ends of each set of five pipes and stick a bolt through it and tighten. Much faster and simpler, not to mention cheaper and easier to store, because there are no hubs whatsoever.
Great dome - I like the prefab nature of it, doing the work up front for easy deployment in the field. Love pvc as a lazy-man's material, cheap and easy to work with. It looks pretty sturdy too - nice job.
wow thanks a good way to do this is goon crag list or free cycle and find some PVC also construction sites different lengths and sizes can be used could i make it fold up with hinges so i can throw in a long bag
Nice dome. I built a similar small dome about 5 ft high from 3.33 ft lengths of 1 inch PVC conduit. To make the hubs I softened the ends with a propane torch and then flattened the ends at a slight angle to account for the dome curvature. Then I drilled the holes and connected together like you did with a bolt. Its been setting outside for over ten years doing various garden jobs. I think I will do an instructable inspired by yours.
something doesn't add up you say you need 30' of schedule 40 PVC. but you say that you need 130 4&quot; pieces. 130 x 4 = 520 520/12= 43 1/3' . or am i reading something wrong. thanks in advance
Thank You! This just solved a riddle I was trying to figure out! Going to build this in a couple weeks!
That's pretty sick! Well done.

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