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.
This small turntable is needed when you need to photograph something or shoot a video in 360 degrees. For the assembly you will need an old CD-drive, a couple of pieces of plywood, a box for batteries, a switch, wires and other trifles.
It all started with the fact that I had a daughter :) Now she is 1.3 years old and she has already learned to deftly sit down to her daddy on her knees and read a book. Each child, like an adult, should have his own chair. Searches in children's shops were unsuccessful, the chairs are all plastic and large or with a hole for the pot. We needed a normal chair for sitting, for a very small girl.
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.