1. Another "Aha!" puzzle “Blockhead”
Bill Cutler won the Grand Prize at the 1986 Hikimi Wooden Puzzle Competition.
Four blocks in a box
Tip them out and then try to put them back!
It’s harder than it looks
This one can be made on the table saw without the use of jigs

2. The “Blockhead” Puzzle
- The four blocks are not quite cubical
- Square on the top
- One side vertical
- Two sides sloping OUT at 5 degrees
- One side sloping IN at 10 degrees

3. The “Blockhead” Puzzle
The sides of the box are undercut by 5 degrees
The box opening is 81mm square (to accommodate the 40mm blocks)

4. The “Blockhead” Puzzle
The sides of the box are undercut by 5 degrees, then mitred at 45 degrees for the corners. A 6mm plywood base to finish

5. The “Blockhead” Puzzle
The stock for the blocks is 40mm thick, then cut at 5 degree and 10 degree angles, giving a width of 40mm on the top
Some trial cuts may be needed to get the 40mm width just right

6. “Blockhead” Puzzle
The "stick" is clamped to the sliding beam, the mitre gauge is set to 0 degrees for the first cut (maybe trimming the wood after the previous block)
The stick is advanced to meet the guide block (fixed to the rip-fence with double sided tape)
The mitre gauge is set to 5 degrees for the second cut
Then the process is repeated. Note that there is a danger of getting both "right handed" and "left handed" blocks (the puzzle would then be impossible!)

7. “Blockhead” Puzzle
The "stick" is clamped to the sliding beam, the mitre gauge is set to 0 degrees for the first cut (maybe trimming the wood after the previous block)
The stick is advanced to meet the guide block (fixed to the rip-fence with double sided tape)
The mitre gauge is set to 5 degrees for the second cut
Then the process is repeated. Note that there is a danger of getting both "right handed" and "left handed" blocks (the puzzle would then be impossible!)

8. A puzzle that needs a complex jig
Nob's "never-ending" puzzle (Nob Yoshigahara – famous puzzle maker)
A cube, sliced in half by an oblique plane

9. Nob's never-ending puzzle
The two half-cubes can be glued together in an L-shape, 16 different ways

10. Nob's never-ending puzzle
Eight of the possible 16 pieces form "Nob's Never-Ending Puzzle"

11. Nob's never-ending puzzle
They can be assembled into many interesting shapes (with some difficulty)

12. Nob's never-ending puzzle
Actually only 11 shapes can be made (and some need to be supported)

13. Nob's puzzle – making the pieces
Making a small cube (just 40mm on a side) and then slicing it across would be difficult, inaccurate and even dangerous
Better to cut a small piece away from a big piece

14. TS200C Table Saw with "Sliding Beam"
The part of the table to the left of the saw blade can slide to and fro 600 mm on rollers. Jigs can be fixed to the T-section slot

15. Nob's puzzle – making the pieces
Jig mounted on the sliding beam has a bar at 90 degrees and a V-groove at 82 degrees
The bolt head engages with the T-slot

16. Nob's puzzle – making the pieces
Square section stock, 40mm x 40mm, ripped on the table saw

17. Nob's puzzle – making the pieces
The saw cuts part way through the jig. The stock is held in the V-groove, offset by 8 degrees.
Note the end stop - a plastic "corner join" block and a bolt

18. Nob's puzzle – making the pieces
When the cut is finished, the small half cube must not be free to move – it might jam between the rotating blade and the end-stop
A plywood hold-down plate is used, secured with three screws.
This anchors the half-cube at the end of the cut. There is not much contact area – the plate is the most secure method

19. The sequence of making the pieces
First trim a number of pieces straight across, using the 90 degree guide
Then, using the V-groove:
- slide a long piece up to the end-stop - secure it with the plate and screws - cut through, thereby making a half-cube - set aside the long piece for later trimming