Sonostar is a California-based company dedicated to the worldwide sale and distribution of high-quality PVC hub connectors and DIY Dome Kits used for the building and repairing of PVC geodesic domes and structures.
Kits and connectors from Sonostar have been used around the world to erect a wide variety of practical, highly functional geodesic structures, including:
In urban or suburban areas, our geodesic hub connectors and dome kits can be used to build durable, lightweight protective swimming pool enclosures and covered outdoor eating areas. Other uses include observatories, aviaries, greenhouses, garages, pet enclosures, and barns.
Prefer art over architecture? Use our geodesic spheres to create decorative, spherical art that showcases your talent and leaves a lasting impression on your audience. The only limit to how you use our Geodesic dome kits and PVC dome hub connectors is your own creativity. Of course, we also remind you that common sense is required in terms of safety and function. While PVC is strong, it does have its limits, and you are responsible for the safety and liability of any structure you make.
Sonostar is based in the USA. All the parts are manufactured and shipped from Southern California. If you’re a do-it-yourselfer, all you need to order is the hubs. If you’re not, but you still want a dome and you know someone who can assemble it for you, then buy the full kit. It will have everything in it you need except for the cover. And stay tuned for the covers. We're going to be rolling out a very cool interactive program that allows you to design your own dome cover in 3D right on your browser. In your dome kit, we provide all of the nuts and bolts you need to assemble your dome. Just input the size you want your dome to be (either radius or diameter). Our geodesic dome and sphere calculators accommodate for the extra width that the hubs take, so you can rely on the numbers and trust the geometry.
At the conceptual level, domes are mathematically inspired structures that contain space, and how you make that container can take on a myriad of configurations. Geodesic domes are universally recognized for their structural efficiency and the symmetry that is so appealing to look at. We want your dome-building experience to be a good one, so we're always available to answer questions. We love seeing pictures of the finished structures from everyone who uses our kits, so be sure to keep your camera handy.
By Jon Dietz, Founder
It started out that I wanted to cover my swimming pool in the winter. I thought to myself, “Why not build a geodesic dome to keep the heat inside?” The research took almost a year, looking at all manner of domes and learning that there is a huge body of knowledge available today to help non-engineers to build basic domes.
Throughout the research, I kept an eye open for connectors that would take advantage of using PVC pipe. It is relatively lightweight, readily available almost everywhere, inexpensive, and incredibly strong. But surprisingly, PVC connectors for building domes were not available anywhere I looked. A friend in the plastics business recommended that I consider making an injection mold. To make the mold, I needed to hire an engineer to work up the specifications into a 3D design.
We wanted the parts to be efficient, but also to be specifically useful for building domes. Since every dome ultimately needs a cover, we made the center of the hub solid, so that whatever cover was used could be screwed into the hub without compromising the strength of the hub. We also wanted the hubs to be usable in both large and small domes, so we initially opted for a 10-degree curvature that would make for a top and bottom side. In small domes, the flex of the PVC pipe would be sufficient to make up the difference. In large domes, the flex would work just the other way around. We chose to start with a hub that would fit 1/2" schedule 40 PVC - probably the most common plastic piping in the world.
Our engineer was able to run the design through a stress-load test that showed us that our hub would withstand at least 100 LBS of angular force on each arm, which is more than enough for a dome where the total load is equally distributed throughout the entire frame.
3D printed prototypes were produced, and after some corrections were made, we had molds built, and produced a production run of the 5-Star and 6-Star hubs. To make the 4-Star connectors, we used a band saw to slice off two arms of the 6 Star hubs.
Once we had the hubs in hand, we were ready to build a dome. It was decided that a 24’ diameter Frequency 4 dome would be a good first project. We determined the six different sizes of struts needed to make the dome (using a calculator we found on the web), remembering to subtract 2.28” from each length to account for the hub width. ½” schedule 40 PVC pipe can be ordered in 20’ lengths, so we ordered 50 pieces and set to work cutting. A Frequency 4 Dome takes 250 pieces of pipe + 65 6-Star hubs, 6 5-Star hubs, and 20 4-Star hubs. It was a huge time saver to use a circular saw, and color-coding the cut pipes with colored electrical tape proved very practical.
Next, we found a big grassy area to start building, and we staged all of the parts where we could easily access them. Since we knew the Dome would be 12’ high, be made sure we had a ladder that could reach the top. Using PVC welding cement, the pieces quickly came together, and within a few hours, the dome was erected.
What to cover it with? Coincidentally, the military uses a 24’ freight parachute that I was able to buy online at a military surplus website. It was a little tricky to position it in the wind, but once it was on, it was easy to tie down. As we built our PVC dome, we couldn't help but think that others might be thinking of building PVC domes, so we started planning a website where others could find and purchase the hubs.
After a few years and hundreds of dome kits sold all over the world, we made some changes to the molds. First, we made a 4-star mold for the base hubs that was stronger than the 6-Star hubs that had two legs cut off. It gave the dome a much more finished look. Second, we found that almost everyone preferred to connect the hubs to the struts with nuts and bolts, as opposed to glue and welding cement, so we built bolt holes for each arm into the molds and started including stainless steel nuts and bolts with every kit.
We got a lot of customer feedback asking us to consider making hub connectors to fit thicker PVC pipe, so the domes could be made bigger and stronger. Once again, we experimented with some models using 3-D printing and found that we could make hubs that fit both 1" PVC pipe on the inside of the arms, and 1 1/2" PVC pipe that fit around the arms on the outside. Once again, we had a complete set of injection molds made, and we put them up for sale on the website. They were an instant hit.
The tests for these showed a 5-fold increase in strength, and they gave users the opportunity to build much bolder designs. We called these new connectors 'Megahubs', because they were so much larger than the 1/2" hubs.
Our company today sells over half our dome kits overseas, demonstrating that imagination and creativity are truly universal. Our R & D department is excited about creating new and useful accessories for our domes that extend their functions. Although we've been in business over 10 years, it seems like we're still just getting started.