A gift i sent to myself and a few friends online. I bought for myself a couple of these https://ugearsmodels.com/horse-mechanoid.html managed to make it work on the second assembly.

It's a nifty 200-piece puzzle, but needed basically the first to understand the tolerances and how resistant the whole model is, i should be able to fix the first with what i have, i don't know if it is worth it, it's basically "a statue" due to me not using sandpaper on the gears themselves and "just following the instructions". The second, as you can see, totally works because i understood where the tolerances are too low and worked with some sandpaper to make them wider.

For anybody interested in building it... basically the problem with the model is that the tips of the teeth of the gears are too close to the "valleys" (being italian i have no clue if those are the proper english terms)so either one should sandpaper the valleys (but that would increas the risk of shearing) or do like me and sandpaper the tips of each tooth of the gears. It does not take much, really, less than a fraction of millimeter, when the gears stop having the black color of the laser cutting you have already taken away enough material for it not to lock.

Also it's very important to remove all the burs in every part that needs to be mobile and use lots of wax on both sides of whatever is going to be moving and touching, not just the axles and the valleys.

😂

This second model is slathered in wax and while at first it might feel like you just locked the model 15 to 30 seconds of microwave melts the wax and makes it seep in the wood, resulting in "perfect" mobility and "lubrication".

Well... as perfect as this thing will ever get.

Given how tight this thing is once assembled and how impossible it is to make further lubrication... i just decided to go with the "nuclear" option described above and making sure it will stay lubricated for a while.

model is "Horse-Mechanoid" by uGears
https://ugearsmodels.com/horse-mechanoid.html