Projects

Wooden Gear Gizmo

Tabletop whirligig is a great 1-day gizmo project for any woodworker
By Rick Hutcheson

If you’ve always wanted to make a gizmo but have been intimidated by complicated clocks and automatons, this is the project for you. This gizmo has enough pieces and gears to make it a fun challenge, but you can probably complete it in a day and it doesn’t need any finicky adjustments. As a bonus, you’ll be amazed by the attention it gets from both kids and adults—people love to fiddle around with this fun machine.

Getting Started
• Print two sets of pattern pieces so you have one for reference as you build the machine.
• For the patterns that require multiple pieces, stack two layers of plywood and cut both pieces at the same time. This assures that the holes in the frames are aligned with each other. I secure the stack by nailing the pieces together in the waste area. You can also use double-stick carpet tape or hot glue on the edges, or wrap clear packaging tape around the stack.
• Cut the 1/4″ (6mm) dowel to length as shown in the Parts List.

 

Making the Gizmo
Step 1: Spray the patterns with temporary bond spray adhesive and apply them to the plywood.

Step 2: Drill all of the holes as indicated on the patterns and Parts List.


Step 3: Cut the pieces with #2/0 reverse blades. The tips and sides of each tooth are the important parts of the gears. These must be smooth, so I start at the base of the tooth to get a consistent, flowing cut.

Step 4: Remove the patterns. Mark each piece lightly with its part number. Use 180-grit sandpaper to sand all of the pieces.

 

 

 


Step 5: Glue spacer C1 onto the end of the short dowel (B). Place a small gear (F2) onto the assembly. Then, glue the dowel-gear assembly into the 1/4″ (6mm) hole in the front upright (I).

 
Step 6: Glue the uprights (I, J) into the base (K) with I in front and the 1/4″ (6mm) hole to the right (see Assembly Diagram). Make sure the holes line up by placing dowels into the holes and rotating them to assure they spin freely. Also, make sure the uprights sit square to the base in all directions.


Step 7: Lay spinner H2 on the table. Glue spacers C2 and D together as shown. Insert a dowel scrap to help align the parts. It’s important that the finished assembly spins freely on the dowel. If needed, redrill the 17/64″ hole after the glue dries.

 

 

 

 


Step 8: Glue the handle (G) on the end of a long dowel (A). Hold a large gear (E) between the uprights and insert the dowel through the bottom hole in the back upright (J). Glue a large gear (E) onto the dowel between the two uprights. Push the dowel through the front upright. Glue small gear F1 onto the end of the dowel, leaving enough space between the gears and uprights that the assembly turns freely.

 

 

 


Step 9: Insert a long dowel (A) through the top hole in the uprights and through large gear (E) between the uprights to the . Again, this assembly should turn freely.

Step 10: Place the dowel-gear assembly from Step 5 onto this shaft. It should turn freely. Place a spacer (D) onto the shaft in front of the assembly.

Step 11: Finally, glue spinner H1 on the tip of the top shaft.

 

 

 

Pro Tip: Selecting the Right Drill Bit
Some 1/4″ (6mm) dowels do not fit tightly in a 1/4″ (6mm)-diameter hole because they are actually undersized dowels. Drill a 1/4″(6mm)-diameter hole in scrap wood and test your dowels for a tight fit into the hole. You may need to use a bit that’s smaller than 1/4″ (6mm) to make a hole that results in a tight fit when you place the dowel in it. Substitute that bit size anywhere that a 1/4″ (6mm) bit is called for to make dowel holes.

 

Materials & Tools:
• Baltic birch plywood, 1/4″ (6mm) thick: 16″ (40.6cm) square
• Baltic birch plywood, 1/8″ (3mm) thick: 1″ (2.5cm) square
• Spray adhesive, temporary bond
• Dowel, 1/4″ (6mm) dia.: 5″ (12.7cm) long
• Sandpaper: 180 grit
• Wood glue
• Finish
• Blades: #2/0 reverse
• Drill with bits: 17/64″ (6.75mm), 1/4″ (6mm)

Parts List:

Part Name Material Needed Notes
A Long dowel Dowel, 1/4″ (6mm) 2 Cut 2 each 2-1/8″ (5.4cm) long
B Short dowel Dowel, 1/4″ (6mm) 1 Cut 1 piece 3/4″ (1.9cm) long
C1-C2 Spacer Plywood, 1/4″ (6mm) thick 2 C1: Drill 1/4″ (6mm) hole
C2: Drill 17/64″ (6.75mm) hole
D Spacer Plywood, 1/8″ (3mm) thick 2 Drill 17/64″ (6.75mm) hole
E Large gear Plywood, 1/4″ (6mm) thick 2 Drill 17/64″ (6.75mm) hole
F1 Small gear Plywood, 1/4″ (6mm) thick 1 Drill 1/4″ (6mm) hole
F2 Small gear Plywood, 1/4″ (6mm) thick 2 Drill 17/64″ (6.75mm) hole
G Handle Plywood, 1/4″ (6mm) thick 1 Drill 1/4″ (6mm) hole
H1-H2 Spinner Plywood, 1/4″ (6mm) thick 2 H1: Drill 1/4″ (6mm) hole
H2: Drill 17/64″ (6.75mm) hole
I Front upright Plywood, 1/4″ (6mm) thick 1 Drill 17/64″ (6.75mm) holes;
Drill additional 1/4″ (6mm) hole
J Back upright Plywood, 1/4″ (6mm) thick 1 Drill 17/64″ (6.75mm) holes
K Base Plywood, 1/4″ (6mm) thick 1

 

 

Click on the links below to download the patterns:
Gizmo Pattern-1
Gizmo Pattern-2
Gizmo Pattern-3

 

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