1. "Cryptex Style" Maze Coin Puzzle
Dalton Area Woodturners Guild
October 27, 2015
Jared Bruckner

2. Outline How I got into coin puzzles
The components of the "Cryptex Style" Maze Coin Puzzle
What I plan to do tonight
Transform a 2D maze into rings
Make the rings
Make the maze block
Make the backbone
Make the pin/coin holder
Make the top and base
Put it all together
Completed Puzzle
Modifications

3. How I Got Into Coin Puzzles
Mike Peace, "Shopmade Threading Jig," American Woodturner April 2013 pp30–34.
John Barkley, All Screwed UP! – Turned puzzles and boxes featuring chased threads, ISBN
Focus on coin puzzles
Designing coin puzzles that did not require threads
James W. Follette, New Wood Puzzle Designs – A guide to the Construction of Both New and Historic Puzzles, ISBN
Bruce Viney, Green Slidey puzzle
Homemade Puzzles
Too easy – Too hard – Just right

4. The Components of the Maze Coin Puzzle Box
Maze block
Top
Bottom
Backbone
Pin/Coin holder
Rings
Pin

5. Transform a 2D Maze Into Rings
Pin
Top

6. Maze & Resulting Rings 1 2 3 4 5 6 7 8 9 10 1 Pin Top Ring 2 Ring 3
Top
Bottom 1 2 7 3 4 5 6 8 9 10
Ring 2
Ring 3 1 2 7 3 4 5 6 8 9 10
Ring 4 1 2 7 3 4 5 6 8 9 10 1 2 7 3 4 5 6 8 9 10
Ring 5

7. Make the Backbone Choose wood 2” by 2” by 4” straight grain and dry.
Cut ¼” slot in the middle of 4” length about ½” deep.
Insert ¼” by 4” by “depth of slot+” piece of wood to fill slot tightly. Trim to fit flat.
Mount in chuck and turn to 1½” round, from chuck out.
Place a spacer in the chuck, reverse ends, and turn the end that was in the chuck to 1¾” round and 3/16” wide. Turn the rest of the end that was in the chuck to 1½” round.
Drill a 1⅛” hole down the middle of the piece.
Alternately, turn between centers before drilling hole in center, but leaving the ¼” slot cut in step 2 empty. Or you might cut the ¼” slot on the bandsaw after completing the other steps – use a jig.

8. Make the Rings
Choose material. 6 pieces ¾” by 2¼” or larger – should fit chuck jaws. I use 3 light and 3 dark colored pieces. If you wish to preserve grain match, mark before cutting.
Place between centers and turn round. If you wish to preserve grain match interchange the 2 blocks on both ends before turning round.
Mark the outside edges with a straight line, and number the disks. 1,2,3,4,5,6 with 1 being the top and 6 being the bottom. To preserve grain match care must be taken here.
Pre-drill the disks to make rings (mark each disk’s position in chuck)
Disks 2-4: 1⅛” hole thru and 1¾” hole ¼” deep
Mark ring 2-4 where stops and cutouts go using 2 colors and slide 8.
Drill ¼” holes inside and tangent to 1¾” hole where there’s a cutout.
Drill ⅛” holes inside and tangent to 1¾” hole where there’s a stop.
Glue ⅛” dowels in each stop hole letting them extend on top and bottom of ring.
When glue is dry, sand top and bottom of rings flush smooth.
Remount rings 2-4 and drill 1½” hole thru each.

9. Make the Maze Block
Using scrap wood about 2½” by 2½” by 4½” - mount in chuck and turn 1½” round from the chuck out making a 4” protrusion. Mark position in chuck.
Using another scrap, about a 2” cube
Square one end and turn a tenon. Make sure the center is marked by the center in the tailstock.
Mount with the tenon in the chuck, square the end, and drill a 1½” diameter hole deep enough so when placed on the end of the previously made piece less than 3” of the 1 ½ round is left between the two pieces.
Mount the first piece in the chuck and wax the protrusion.
Glue the rings in order from 2 to 4 and use the second piece and the tailstock to press the rings together.
When the glue has set you might remove it and place in a clamp to finish drying.

10. Make the Pin/Coin Holder
Choose wood 1½” by 1½” by 4”, straight grain & dry.
Mark center of one end and mount in chuck.
Bring up revolving center in tailstock.
Turn to 1⅛” from chuck out.
Sand and make sure Pin/Coin holder fits well.
Part off near chuck.

11. Make the Top and Base
Mount the Top disk in the chuck, using a spacer, with the bottom out and
Drill a ¼” hole centered on a 1¾” circle anywhere on the circle and about ½” deep
Drill a 1½” hole ½” deep centered.
Drill a 1⅛” hole leaving at least ⅛” of wood
Drill a ⅞” hole all the way through
Carefully turn the 1⅛” hole to leave about 1/16” of wood
Sand
Remount with the top out and sand.
Mount the Bottom disk in the chuck with the top out and
Drill a 1⅛” hole ½” deep
Remount with the bottom out and
Do whatever decoration you want on the bottom

12. Fitting & Finish Turning (1)
Jam chuck the Top and Bottom and turn to desired diameter (about 2½”), shape and sand.
Using the jig used to glue the rings together, turn the ring block to the desired diameter (about 2”) and sand. Take care that the jig is positioned in the chuck correctly and that the protrusion is turning dead on.
Carve a hole in the top for the pin to sit in if this was not done when the Top was made.
Size the length of the backbone by marking the backbone where the ring block and top currently meet it and remove the distance between the two marks from the backbone’s length. I suggest using a 1⅛” round dowel inside the backbone on the chuck end with the top of the backbone in the chuck when parting off. Sand the bottom end of the backbone. Final fitting may be done by sanding using the ring block as a jig to sand the top of the backnone – be careful not to sand too much on the ringblock.

13. Fitting & Finish Turning (2)
Check the length of the ringblock around the edges and sand to make square.
Mark the pin position on the coin/pin holder by inserting the backbone into the ringblock and the coin/pin holder into the backbone without the top and marking where the pin should go - ⅛” from the ringblock.
Size the length of the coin/pin holder by placing the coin/pin holder in the hole in the Bottom and marking where the bottom of the ringblock meets the coin/pin holder (Not where the backbone meet the coin/pin holder) and where the coin/pin holder meets the Bottom. Remove the distance between the two marks from the length of the coin/pin holder.
Drill a 1” hole in the top of the coin/pin holder about 1/32” deep. Enlarge the hole slightly and turn it deeper so the $1 coin fits somewhat loosely. This helps remove the center hole made by the drill bit.
Drill a ⅛” hole for the pin. Pin should extend a little over ¼” from the coin/pin holder. Make pin and check fit, but do not glue yet.

14. Putting it All Together
Check that the puzzle works by running the coin/pin holder, with the pin inserted (not glued) through the maze block. Modify pin if needed.
First glue the top to the backbone with the maze block in place. You might want to wax the top end on the maze block. Make sure that the maze block turns smoothly.
When the glue has set, wax the bottom of the backbone and glue the coin/pin holder in the bottom using the rest of the puzzle as a gig to get the coin/pin holder straight. The pin does not need to be in place yet.
Last, glue the pin into the coin/pin holder. I use thin CA glue and saturate the pin good.

15. Completed (Dumbbell) Puzzles

16. Other “Cryptex Style” Puzzles