Checkered Tetrominoes

thingiverse

Puzzle description: There are 10 different on-sided checkered terominoes which should be packed into a square or a rectangle with the correct checkerboard pattern. The first goal of the puzzle is to select nine of the ten tetrominoes and pack them into a 6x6 square. The tray contains a space for the spare tetromino. Note that a T-tetromino cannot remain as a spare tetromino, this can be shown with the usual parity argument. For eight different spare tetrominoes (except the T-tetromino) you have eight different tasks. Additional goals are * Fill a 5x8 rectangle with all tetrominoes. * Fill a 4x10 rectangle with all tetrominoes. * Difficult: Fill two 4x5 rectangles using all tetrominoes. If you can read German: Mehr Informationen gibt es in https://welt-der-geduldspiele.blogspot.com/search?q=3D-Druck Puzzle difficulty: The puzzle may look easy, but some tasks are difficult. The number of solutions varies from task to task. Printing instructions: The main color (usually gray or black) is used for the pieces and half of the caps. A second color is needed for half of the caps for the checkerboard pattern. The caps can easily be snapped onto the pieces. For the 10 pieces you need * 2 copies of the tetrominos L4, L4M (mirrored) and T4, printed in the main color; * 1 copy of the remaining parts I4, O4 , Z4 and Z4M, printed in the main color; * 18 caps printed in the main color, * 18 caps printed in the second color. A tray for the 6x6 checkerboard with space for a spare part also is provided. The tray was designed using PuzzleCAD: https://www.thingiverse.com/thing:3198014 Prints are fine with no supports. Snap the caps onto the different parts as in the picture. The caps are printed upside down, so the pieces will have a very flat surface. Be sure to use the correct checkerboard pattern for the pieces. I printed the puzzle in PLA at 0.1 mm layer height.