Folding Chair-Height Stool with Fold-Down Backrest (STL)

A real chair-height folding stool you can print on a 220 x 220 mm bed. Seat height 42 cm, folds down to 22 x 21.5 x 16 cm, designed and stress-checked for a 250 lb (113 kg) adult with a 2x impact margin.

How it works: two leg frames hinge at the seat ends and each has a knee, so the legs reach chair height from bed-sized parts. All locks are gravity-operated - pawls drop into the hip hinges and hooks drop over the knees when you stand it up. Turn it upside down and every lock falls open, so it folds in seconds. Detents click the frames into the open and folded positions.

Contoured seat: raised back, flat sitting area, and the front and side edges slope away so nothing presses into your legs whatever your size.

Optional fold-down backrest: slides into the back of the seat, held by one drop-in pin. It folds forward onto the seat for carrying, or comes off completely.

Includes 16 STL files, a parts list with print counts, recommended settings (PETG, 5 walls, 40% gyroid) and assembly steps. Pins can be printed or swapped for steel rod / M5 bolts.

License: print it and sell the prints freely; do not share, distribute or sell the files.

Printer: any 220 x 220 x 250 mm bed (Ender-3 size). Material: PETG recommended, about 2 kg total. 0.2 mm layers, 5 walls, 5 top/bottom layers, 40% gyroid. All parts print without supports except the seat (tree supports from build plate under the contoured top). Pins at 100% infill or use steel. Parts: seat, 2 upper legs, 2 lower legs, 4 hooks, 2 pawls, pins and cotters; backrest add-on: bracket, backrest, hinge pin, lock pin. Inspect pins before each use.

Also on Cults3D: https://cults3d.com/en/3d-model/home/folding-chair-height-stool-with-fold-down-backrest-250-lb