When I saw the "Kinetic Gear Toy" , Alex Fox did, I had to try it. I didn't have 4 mm BB so I used 1/8". Cutting the pieces was quick and easy. I had some 1/8" dowel so decided to use it for the pins. Well that didn't work, the dowel was too soft, too small and just kept breaking. So I re-drilled the holes to 5/32" and used bamboo skewer for the pins. Then came the gluing. First I tried "Contact Cement" because it was stated that it was the closest thing to what Alex uses. I could not get it to hold. The gears that needed to stay stationary on the pins,,, didn't. Then I use Titebond II, and it would not hold. Keep in mind there is a very small gluing surface to glue the top gears to the pegs. So I purchased some "Gorilla Super Glue" and it appeared to work,,,, well almost...... turn your sound off, I may have said something I shouldn't have.... Oh, well It is worn out from me gluing, sanding, re-gluing. Going to take a break and try again with 1/4" BB and 1/4" dowels. Still I have had fun trying...
https://imgur.com/U2UHURj
OOPPPSSSSSSS!