The 3d-printed spherical frame (truncated icosahedron) used to hold modules together for soldering. Please note scale might not be 100% accurate based on your printer settings, module tolerance, etc. You might need to print few iterations and modify as needed.
Standard Tesselated Geometry -
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10/20/2018 at 23:50
3D-print a soldering fixture to hold modules together
We 3d-printed a shell model of half truncated icosahedron (soccer ball) shape to use as soldering fixture. Holes in the fixture are used to hold modules in place using M2 screws while being soldered.
Solder the first half of the sphere
Solder the first half (10 modules). Start by doing the upper ring and attaching five modules to the fixture using M2 screws. Solder main joins (array ports) then remove the modules from the fixture and solder remaining joints from the other side (internal side). Put this back on fixture and attach the next five modules and solder them similarly.
Alternatively, you can also solder all ten modules from the outside, then remove the shell from the fixture and solder the internal joints.
Solder the second half of the sphere and join the two halves together
Repeat step 2 by soldering the second half of the sphere. After that, put the two halves together and solder them from the outside and the inside. Try to get as many solder joint as possible. Particularly important are array joints (the ones in the middle of the module side) as you really need to solder all of them to get full connectivity. You can skip some power (corner) joints if they're hard to reach. This really requires some ninja soldering skills but it gets easier with training and better with patience.
We messed up dimensions a bit in the 3d-printed fixture and ended up with small displacements and alignment errors between modules. Solder surface tension helps you a bit in bridging these miss-alignments but you really need to be patient with such project and pay attention to dimensions because geometrical alignment is key. Once finished assembling the modules, you can add whatever connectors/wires you want (e.g., for power).