Mastermind is a great game! I wanted to continue my learning of Fusion 360 and used this project to help. I am giving this to my nephew and niece as a Christmas gift.
You could modify the top and the clue drawer to do Super Mastermind (6 color in a guess, and I think 8 possible colors to guess from), which I may do eventually. (Contact me if you want me to figure out how to send you the fusion 360 files to try yourself). For now, you can up the challenge by printing extra colors, or just allowing one of the colors to be empty.
(A proper Super Mastermind should probably have everything scaled up a bit, so that you have room in the drawers to fit more pegs, and so that there are more total guesses allowed).
I used 0.15mm in my prints, but the resolution doesn't matter much. I print box.stl standing tall, the other models print with on their bottom (or in the case of peg.stl, on their top).
Also, I printed 16 of each color peg, 8 total colors -- two colors should be reserved for giving clues. Otherwise, you need to print more of those two colors if they can be included as part of the secret.
Easy to assemble!
The only post processing needed is to glue the top.stl to the box.stl. I used CA (super) glue, after lightly sanding both surfaces to ensure good contact.
When inserting the drawers into the box, you just push them in directly (no need to try to put them in one corner at a time). You may have a smidge easier time doing so before you do the gluing step above, but you should not find it impossible either way.
Overview and Background
How to play
Mastermind is a game of logical deduction, one player gives clues about his secret code that the other player makes guesses about until he discovers the secret. (You can see a game played out above -- black pegs indicate a guess has a color that is in the exact right spot, and white pegs indicate a guess has a color that is right, but in the wrong spot).
Children are introduced to this concept can help expand their reasoning. At first, just making random guesses might help them eventually solve the puzzle before 10 guesses are used. But as they see patterns in right and wrong choices, they can reduce their total number of guesses.
Lesson Plan and Activity
Suggested way to introduce play
I recommend bringing the difficulty down a good bit for the first game. Take away two of the colors and require a secret to not have any repeating colors. (This means we know already it's exactly one of each the remaining colors, and the guesser is really just guessing the order). If the children get used to this quickly, then jumping straight to 6 colors next makes sense.
Finally, I'd recommend introducing the "full" game where they are allowed to have multiple of the same color in a secret. (And as mentioned in the summary, true masters of the game can play with more than six colors)!
Children can also play in team pairs so they can help each other. Two secret clue givers can work together to ensure they do not make a mistake -- they can take turns placing the black peg and white peg clues, with the other having the responsibility to check their work. Two guessers can help each other spot patterns in their guesses to make a better next guess -- they can also take turns.
(And at an expert level, two children can play two copies of the game at the same time, where each is giving clues on one copy and guesses on the other).