I present to your attention a homemade 3d printer. Assembled from plywood, aluminum, plastic and Arduino. This printer is unique in that its kinematics is peeped from Ultimaker, but done with quality modifications.
Almost all toys bought for the daughter do not cause the child's interest, which can not be said about developing toys made by themselves. Below is a photo of the simplest developing mat, which the wife made for a couple of evenings from old buttons.