9-piece board burr set (21 puzzles)

This is a 15-piece set I've created to build and solve 21 9-piece board burr puzzles of increasing difficulty.

The idea is to use 3 same-colour pieces for each one of the 3 axes, to bring down the difficulty.

Here is a PDF with all 21 puzzles and instructions.

Here is the BurrTools file with all the solutions (each puzzle has the specific BurrTools solution listed, so it's easy to find).

If the puzzles are too hard, you can use BurrTools to assemble them and then solve the puzzle as a disassembly.

I hope you enjoy them!

Carlos