How to Create a Spinning Rubber Duck Gear Mechanism

Overview

This Instructable will guide you through creating a simple rubber duck gear mechanism. This project involves 3D printing, basic woodworking, and mechanical assembly, making it a great educational tool and a fun project for enthusiasts of all ages.

Inspiration

The inspiration came from classic mechanical toys and the desire to make a functional, interactive model that can demonstrate basic gear mechanisms. It combines modern technology with traditional crafting methods.

Materials:

PLA Filament (for 3D printing): PLA is a biodegradable thermoplastic that is easy to print with.

1x Wooden Base: A 12x12 cm piece of wood, 1-2 cm thick, will provide a sturdy base for your mechanism.

6mm Wooden Dowel: These will be used as the shaft for the gears and to secure the duck to the mechanism.

2x 8x1/2" Screws: Small screws to secure the shaft holder and gears to the wooden base.

1x Rubber Duck (or toy of your choice) Model: Small, 3D-printed. You can design this in CAD software or download a model from an online repository.

Sufficient 7mm Flat Washers: These will help secure the dowels and ensure smooth rotation of the gears.

Tools:

3D printer

Fusion 360 (or similar CAD software)

Pillar drill

Center punch

Junior Hacksaw

Screwdriver

Sandpaper

Wooden vice

Start by designing the components in Fusion 360 or any other CAD software. You will need to create:

Bevel Gears: The driver gear (pinion) with 20 teeth and a diameter of 64mm, and the driven gear with 40 teeth and a diameter of 30mm.

Shaft Holder: A small component that will hold the driver gear in place, ensuring it is properly aligned with the driven gear.

A cylindrical piece that fits into the center of the bottom gear, connecting it to the wooden base.

Handle: A handle that attaches to the driver gear, allowing manual operation of the mechanism.

Rubber Duck: Either design a toy or download one from a model repository.

Ensure that all components fit together with appropriate tolerances. For example the holes for the dowels should be slightly larger than the dowels themselves to allow easy assembly.

Export the CAD designs as STL files and 3D print them using a slicing software like FlashPrint. Ensure the dimensions are accurate, and the prints are clean.

Remember to enable supports for overhangs, especially for the toy and the gears.

Mark out the positions for the components on the wooden base. Use a try square and ruler to ensure accuracy. Punch holes where the dowels and screws will go.

For the shaft holder place it near one edge of the base when marking out where the screws will go, ensuring there is enough room for the gears and handle to rotate freely.

Part 1:

Hole for Axle: Drill a 6mm hole where the axle will be inserted. This will hold the driven gear. Use a pillar drill to ensure the holes are perfectly vertical. Set the depth stop so that the drill bit doesn’t go all the way through the wood, stopping about 7mm deep or however thick your base is before it goes through completely.

Shaft Holder: Secure the shaft holder to the base by drilling it in with screws.

Safety: Goggles

Part 2: Drilling into the Rubber Duck

Before drilling, mark the center of the rubber duck’s bottom where the dowel will be inserted. This is important for ensuring the duck sits securely and upright on the gear.

Place the rubber duck into a wooden vice to hold it steady during drilling.

Use a 6mm drill bit, the same size as the dowel, and carefully drill a hole into the marked spot. Ensure that you drill straight into the duck to avoid an angled hole, which could cause the duck to sit crookedly.

Drill to a depth of about 20-25mm, which should be sufficient to hold the dowel firmly. If the duck is hollow, be careful not to drill too deep, as this could puncture through to the other side.

Insert the 6mm dowels through the gears and into the drilled holes. Ensure the gears are aligned and can rotate freely without obstruction.

Attach the handle to the axle and ensure it is tightly fitted to control the rotation.

Place the rubber duck on the driven gear, ensuring it is securely attached.

Turn the handle to test the mechanism. The gears should rotate smoothly, causing the rubber duck to move in a circular motion.

Optional:

1. Lightly sand the wooden base to remove any rough edges or splinters. You can also apply a wood finish or paint for aesthetics.
2. Consider adding more decorative elements, such as painting the gears or the duck, or attaching additional figures to the mechanism.

Common Issues:

Gears Not Meshing Properly: Check the alignment of the gears and ensure they are at the correct distance from each other.

Loose Components: If any parts are loose, consider applying a small amount of glue or using tighter-fitting screws.

Rough Movements: Ensure all moving parts are sanded smooth and rotates freely without friction.

You've now completed your rubber duck gear mechanism! This project not only demonstrates the principles of mechanical engineering but also serves as a fun and interactive toy. Good job!!