Eric wrote:First time I see geomag structures with spheres that big!
Well done!
Originally, I bought the spheres of 30mm and more for different Large/Giant Stick sets intended for toddlers. For obvious reasons, these sets come with lightweight hollow tin spheres. But I like the shiny silver spheres better.
Eric wrote:Unbelievable it doesn't collapse without geomag pro-L.
It depends a lot on the build and the angles at which the forces act. Lateral forces are always critical, and the larger the sphere, the shallower the calotta that enters the rim of the rods.
With this build, the acute angles lead to steep rods between the layers. The weight of a sphere is supported by one or two rods, and the pull force of the middle layer corner spheres is distributed on three rods.
Also, you can initially build the corner elements as Triangular Bipyramids, and remove the cross-bar when the work is done.
I hope that you find spheres of appropriate size (22-35mm), so you can try this build yourself.
PRO-L is a good hint. Usually, I don't use these, because the magnetic strength is not that much more, and the slightly higher weight almost compensates that. But with large spheres, the PRO-L might be helpful.
I only have 20 of the 50mm spheres, but I'll definitely try to build an Order-2 or Order-3 version with PRO-L rods and 45mm Spheres. A Masterbox of 144 would even be enough rods for Order-4.
