Everyone who wants to participate can build their own capsules. Please post your pictures, drawings, instructions and experiences here as inspiration for others.
Capsules with light are better, but not needed.
Tube dimensions (verified by measurement): Outside diameter: 100 mm Inside diameter (the tube is corrugated): 90-92mm
|Diameter||75 mm||90 mm||85 mm||also depends on capsule's sides, if soft, thicker may be better|
|Length||100 mm||220 mm||180 mm||too short might cause it to turn and get stuck, too long will not get around corners. (rounded and narrowed ends can be longer)|
|Weight||-10 t||550 g||250 g||large weights need to be tested more on long tubes going up|
The ends of the capsule should be round or narrowed, so it can easily glide around bends. Take a look at how commercial capsules look like for inspiration: http://commons.wikimedia.org/wiki/File:Rohrpostbuechse.jpg
Be aware! There will be massive force at the front and the back of your capsule, as it will most likely hit something hard like the floor, the end of a tube or something other..
Do NOT buy commercial capsules. They won't fit!
A capsule made by cutting a ring out of a 85mm 1.5l PET water bottle and putting the ends back together worked really well in experiments.
At the largest diameter a ring of felt or the soft side of velcro should be applied to ease the gliding through the pipes and provide a better airtight seal between tube wall and capsule.
Capsule Ideas: Multicolor glowing capsules, capsules with e-paper displays, encrypted capsules (with puzzles or locks).
... once printed, assembled or bought.