What gear ratio can I achieve with the worm gear pairs?

Typical worm gear sets in this size range achieve ratios from approximately 10:1 to 40:1 per stage. Exact tooth counts vary by piece; count teeth to determine the specific ratio for your application.

22pcs Mixed Plastic Toothed Wheels Worm Crown Gears Toy Robot Part 2MM - 4MM

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22pcs Mixed Plastic Toothed Wheels Worm Crown Gears Toy Robot Part 2MM - 4MM

HomeDIYer

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Packing Qty:: 1set

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$9.49 USD

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In stock (500 units), ready to be shipped

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22pcs Mixed Plastic Worm Crown Gears — Compact Drive Components for Robots & DIY Builds

When your robot project stalls because you can't find the right gear ratio, or your small-scale automation prototype needs a reliable motion transfer solution, sourcing the correct toothed wheels in one go is half the battle. This 22-piece mixed gear set is designed for makers, hobbyists, and educators who need a versatile assortment of plastic worm gears, crown gears, and toothed wheels ready to drop into their next build.

The set includes 22 individual plastic gear pieces spanning shaft bore diameters of 2 mm and 4 mm (approximately 0.08 in and 0.16 in). Gears are molded from engineering-grade plastic — typically ABS or POM — offering a balance of light weight and adequate rigidity for low-to-medium torque applications. Outer diameters across the assortment range from approximately 10 mm to 40 mm (0.39 in to 1.57 in), covering a practical spread of gear sizes in a single kit.

Typical use cases include DIY toy robot drive trains where worm gear self-locking is needed, RC model vehicle gearbox prototyping, and STEM education kits demonstrating gear ratio and mechanical advantage. The mixed assortment also suits small motorized gadgets, clock mechanisms, and desktop automation experiments where metal gears would add unnecessary weight.

⚙️ Compatible with 2 mm and 4 mm motor shafts — fits common TT motors, N20 micro motors, and standard hobby DC motors used in robot and RC builds.

✅ Key Features of These Mixed Plastic Worm Crown Gears

🔩22-Piece Mixed Assortment — Includes worm gears, crown gears, and spur-style toothed wheels in one kit, reducing the need for multiple separate orders during prototyping.
📏Dual Bore Sizes: 2 mm & 4 mm — Covers the two most common micro-motor shaft diameters, making the set immediately usable with TT motors, N20 motors, and similar hobby actuators.
🪶Lightweight Engineering Plastic — Molded from ABS or POM-type plastic for low rotational inertia, reduced motor load, and quiet operation compared to metal equivalents.
🔄Worm & Crown Gear Geometry — Worm gear pairs provide inherent self-locking behavior ideal for lift mechanisms and positioning stages; crown gears enable right-angle power transmission.
🎓STEM & Education Ready — Sized and priced for classroom kits, science fair projects, and maker workshops where students can explore gear ratios and mechanical advantage hands-on.
📦Multi-Pack Options Available — Choose 1-set, 5-set, or 10-set packing quantities to stock your parts bin or fulfill small-batch production runs without overpaying per piece.

📐 Technical Specifications — Mixed Plastic Worm Crown Gear Set

Piece Count per Set	22 pcs
Gear Types Included	Worm gears, crown gears, toothed wheels
Shaft Bore Diameters	2 mm / 4 mm (approx. 0.08 in / 0.16 in)
Outer Diameter Range	Approx. 10–40 mm (0.39–1.57 in)
Material	Engineering plastic (ABS / POM type)
Color	See variant options
Compatible Shaft Types	Round shaft, 2 mm and 4 mm diameter
Recommended Motor Types	TT motor, N20 micro motor, standard hobby DC motor
Application	Robot drive trains, RC models, STEM kits, small automation
Packing Quantity Options	1 set / 5 sets / 10 sets

❓ Frequently Asked Questions

Which shaft diameter should I choose — 2 mm or 4 mm?

The set includes gears with both 2 mm and 4 mm bore sizes. Check your motor's output shaft diameter before assembling. N20 micro motors typically use 3 mm shafts with a 1 mm flat, but many hobby variants ship with 2 mm shafts. TT gear motors commonly use 3–4 mm D-shaft outputs. Measure your shaft with calipers before pressing a gear on.

Are these gears strong enough for a robot that carries weight?

These plastic gears are suited for low-to-medium torque applications such as small wheeled robots (under ~500 g payload), light conveyor mechanisms, and positioning stages. For heavy-load or continuous high-torque applications, metal gears are recommended. Worm gear pairs in this set provide self-locking, which helps hold position without motor power.

Will these gears corrode or degrade over time?

Engineering plastics like ABS and POM are inherently corrosion-resistant and will not rust. They perform well in typical indoor environments. Avoid prolonged exposure to strong solvents, UV radiation, or temperatures above approximately 80–100 °C (176–212 °F), which can cause warping or brittleness.

Are these compatible with LEGO or other standard building systems?

These gears use 2 mm and 4 mm round bore shafts and are not dimensionally compatible with LEGO Technic axles (which use a proprietary cross-axle profile). They are designed for use with standard round hobby motor shafts. If you need LEGO-compatible gears, please check our other listings.

How do I decide between the 1-set, 5-set, and 10-set options?

The 1-set option is ideal for a single project or to evaluate fit before committing. The 5-set and 10-set packs offer a lower per-piece cost and are suited for classroom kits, maker workshops, or small-batch production where you need spare gears on hand. All packs contain the same 22-piece mixed assortment per set.

Can I use these gears with 3D-printed parts?

Yes. These gears work well alongside 3D-printed brackets, motor mounts, and gear housings. Because the bore diameters are standard (2 mm and 4 mm), you can design or download shaft holders and gear carriers in CAD software and print them in PLA or PETG for a secure fit.

What is the gear ratio I can achieve with the worm gear pairs?

Gear ratio depends on the number of teeth on the worm wheel (crown gear). Typical worm gear sets in this size range achieve ratios from approximately 10:1 to 40:1 per stage, providing significant speed reduction and torque multiplication. Exact tooth counts vary by piece; inspect each gear visually or count teeth to determine the specific ratio for your application.

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