This Instructable describes the process and the tools used to realise a 3D design using a FDM/FFF printing process that can be applied to puzzle creation.
Having made a variety of puzzles, I decided to make one that was both cubic and difficult.
Each piece is made up from a number of uniform squares creating unique shapes.
Sizes for the shapes consist of a minimum of 5 squares to a maximum of 15 squares.
The orientation and layout of the pieces ensure that they interlock together.
No clips or pegs are required to hold the pieces in places which means that the puzzle can be assembled and disassembled as many times as required.
The puzzle consists of 24 pieces that make up a 6 x 6 x 6 cube with only one solution, the purpose being to connect the interlocking pieces in the correct configuration to complete the cube.
It is difficult (but possible), to find the solution using only logic or trial and error.
The puzzle was designed with the aid of BlocksCAD
Step 1: Creation
I create each piece one at a time by the combination of the cubic object.
Starting with the first layer, I manipulate the shapes to fit as I go ensuring that each piece interlocks with its neighbours.
To aid the process I colour each shape to make it distinctive and therefore see each individual element.
One critical factor in the whole process is the orientation of the shape in relation to how it will be 3D printed.
All the pieces will be printed in on go and will be orientated in such a way that no supports will be required nor any overhangs be present.
In the example the shape made of 9 cubes as positioned clearly has a 1 cube overhang.
But this cube within the shape would require a support if orientated in this manner.
Therefore, the shape will be rotated along the X axis by 90 degrees as in the second example.
There is now no overhang and therefore no requirement for a support.
Each shape has to meet this requirement.
Step 2: Interlocking
Each piece has to interlock at a point or points either on the specific shape and its neighbours in such a way that the pieces can actually be assembled.
The example illustrates 3 shapes and how they will inter lock with their neighbours.
The purple and the and gold shape overlap each other at two points.
The green shape then overlaps both the purple and gold shapes. At two points over the gold shape and one point over the purple shape, whilst at the same time clasping the overhang of the purple shape.
Once assembled each of these pieces and their neighbours will be held by surface friction due to shape tolerance and surface finish.
Step 3: Interlocked Cube
All of the individual elements are placed until the entire cube is completely formed.
The cube is not hollow and is fully formed of visible external elements and invisible internal elements.
Although, the vast majority of the elements are externally visible even if it is only by their ends.
Step 4: Unlocking the Cube
Now that the cube has been completely assembled it needs to be disassembled and each piece orientated to lay flat with no overhangs.
Once this is complete the OBJ file can be created.
Step 5: Printing
Using Cura the OBJ file is loaded and and preferences adjusted prior to printing.
Resolution 0.15 mm with 3 layer wall count, 20% Tri Hex infill and Brim.
With these parameters:
25% of full size will take ~1h:1m, size 55.8mm x 40.8mm x 7.5mm
These parameters are subject to filament, printer or other preferences.
Once the puzzle is printed the pieces are separated from the brim.
Some post processing in the form of sanding may be required depending upon print quality and the filament used.
Then comes the fun and satisfaction of putting it all together to complete the puzzle.
Step 6: Over to You
These are the tools and processes I adopted to realise this design during its inception.
Hope you found this instructive and will attempt to design your own puzzles.
Step 7: Updates
I have since made some minor improvements to the original design.
You can view and download the new design here: Cubic Puzzle 24 piece 6 x 6 x 6