Plastic gears offer a low-cost alternative to brass, carbon steel or other metal gears. You can find a plastic worm gear in a variety of places from the string tightener on a musical instrument to the automatic transmission in your car. While manufacturers limit the use of plastics for gears to small plastic gears, advances in composites have made it possible for you to buy plastic gears of larger sizes. The lower price of plastic gears has also encouraged engineers to expand the use for these gears beyond traditional plastic hobby gears.

The toy and hobby industry is an area where you will find extensive use of plastic gears. Hobby groups including radio control enthusiasts continue to debate the actual cost and efficiency of plastic gears over other materials. Some of the benefits include the following aspects:

1. Plastic gears weigh less than metal gears.

2. Plastic gears function with little or no lubrication.

3. Plastic gears resist corrosion in high-moisture environments.

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Look for rare plastic gears to meet your specific needs

If you are building your own machine, such as a robot, aircraft, monster truck, train or boat, you may need a gear that is hard to find. You can find a source for miniature bevel gears or plastic spur gears, for example. Or you may wish to find a company that will help you design your own plastic spur gear.

I recommend: Engineeringtalk, in addition to enumerating the advantages of plastic gears, lists a wide range of gears costing from $3 to $11 with discounts for larger purchases. It quotes sizes in both inches and metrics. Plastic Machining boasts that it has the largest inventory of plastic gears and will quote you a price for a custom-made plastic gear.

Consult the experts for their opinions on plastic gears pricing and costs

Engineers and mechanics state their opinions on the cost of plastic gears. Usually, this appears as an argument for or against using plastic gears instead of using metal gears. Plastic gears are initially cheaper to manufacture, but if they fail to last as long as a metal gear, you must then figure in the cost of downtime and expense of replacement.

I recommend: Power Transmission discusses the use of plastic gears in automobiles, pointing out that the lighter weight promotes fuel efficiency. It offers information on why plastic gears may cost more in the long run. PlasticsTechnology presents an article on the advances plastic gears offer in materials and efficiency and includes a section comparing costs to metal gears. It estimates that plastic gears cost 50% to 90% less than metal gears.

Shop to buy plastic gears at the best price

You will find an abundant supply of sources ready to help you find plastic gears. Online, you will be able to compare cost among plastic gear sellers and compare the cost of plastic gears to metal gears.

I recommend: Quality Transmission Components pictures a large number of all kinds of gears for sale, making it possible to compare prices between plastic and other materials. Select plastic spur gears to get specifications and a catalog number which will lead to pricing, beginning at about $10 for a single gear. Gizmoszone caters to the robot-building customer and exemplifies a specialty gear supplier. It offers prices, beginning at $2 per gear, and specifications.

Plastic gears can offer many advantages over metal ones. They are quieter, weigh less, have lower inertia, cost less and are more resistant in corrosive environments. With today’s stronger engineering polymers and advances in molding processes, the use of plastic gears has expanded from low power transmission applications into higher demanding ones. You can find plastic gears in diverse uses like laser printers, gear pumps, appliances, toys and many specialized areas, like automotives and military applications.

Gears are toothed devices, used in conjunction with another gear and component to transmit motion. By meshing two gears of different sizes, you can produce a variation in both speed and torque between the shafts. There are many types of gears, but spur, worm and helical are the most common ones. For plastic gears, some important specifications to consider are number of teeth, teeth ratio, pitch diameter, pressure angle, shaft length/diameter and power transmission requirements. Other parameters to review before you buy plastic gears are:

1. Get plastic gears online from suppliers that carry an extensive selection of different types and sizes.

2. Locate manufacturing services that custom design and fabricate gears to customer specifications.

3. Consider plastic hobby gears for your customer needs.

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Find out where to buy plastic gears

Many times, you need a variety of gear types for your business. Whether looking for one specific plastic worm gear, metric plastic gears or for many small plastics gears, the best solution is to shop from suppliers that offer a good assortment in different sizes, diameter and types and who can provide technical assistance.

I recommend: Find metric plastic spur gears and worm gears and many other types of gears at Quality Transmission Component. The company offers spur gears in sizes from module one to ten in nylon and acetal; worm gears are also available in nylon. You can place orders online as well as see the huge catalog with a technical reference section. Go to Rush Gears Inc. for a vast selection of nylon plastic gears (worm, spur and others) in metric and inch sizes. You can get quotes, technical information and use engineering calculators. MSC Industrial Supply Co. also carries an extensive selection of plastic spur gears. For small plastic gears, go to W.M. Berg, where you can select small spur gears in molded acetal and other materials.

Get precision plastic gears from an experienced design team

Custom plastic gear design is an area of special expertise that requires a team capable of meeting and exceeding your design expectations. For complicated gear design applications, you need a company that can offer a wide range of services from design, tooling, molding and more.

I recommend: ABA-PGT Inc. manufactures precision plastic gears and provides complete gear train design, mesh analysis and more. Performance Gear Systems, Inc. also manufactures and provides design and analysis services for your application needs. For complete information on custom gear design solutions, contact Kleiss Gear Inc. They also provide examples of specific molded gear designs as well as technical articles.

Purchase plastic gears hobby supplies for your store

Toys, robots, science fair projects and many hobby projects need the use of plastic gears. If you run a hobby store, stocking up and having a good supply of gears on hand will ensure that your customers keep coming back for their hobby needs.

I recommend: Go to American Science & Surplus for spur, bevel and combination gear sets and repair kits. Edmund Scientific carries packages of gears in assorted sizes and colors. A Main Hobbies and The PRObelay Group also carry plastic gears for many hobby needs.

Tips & Tactics

Helpful advice for making the most of this Guide

• •  For metric plastic gears, the term module denotes the center-to-center distance between successive teeth.

Promote yourself professionally with your understanding and use of plastic gears key terms. Understanding these terms shows clients and other business professionals that you have an awareness of what's going on in the industry. It demonstrates that you are knowledgeable about current products and industry terms.

When you use plastic gears key terms, it also helps you communicate clearly to others in the field exactly what you are looking for. Make sure you have the right materials for a product by using proper plastic gear terminology.

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Worm gear

A worm gear is a shaft with a screw thread that forms a mesh with a toothed wheel. It has slightly slanted teeth, and the gear changes direction in the rotary motion of the axis.

I recommend: Stock Drive Products/Sterling Instrument offers plastic worm gears in a variety of sizes. Businesses can search for the product they need based on width or angle.

Bevel gear

A bevel gear is a conical-shaped gear that has intersecting axes. This type of gear generally mounts on shafts 90 degrees apart. However, based on its design, it can work with other angles also.

I recommend: MFG.com offers information on the bevel gear.

Spur

A spur is a device formed from gear wheels that come together on the same plane. It transmits a rotational force to another gear on the same plane.

I recommend: Avon Gear and Engineering specializes in various types of precision-cut gears, including spur gears. It tailors products according to your unique requirements.

Miter

A miter gear is a special form of the bevel gear. These gears operate in pairs and have identical diametrical pitches and teeth.

I recommend: Quality Transmission Components provides detailed specifications for its plastic miter gear.

Acetal resin

An ingredient in plastic gears, Acetal resin is a type of engineering plastic used as a substitute for metal. Manufacturers also use names like polyoxymethylene, POM, polyacetal, polyformaldehyde, polytrioxane or paraformaldehyde to refer to Acetal resin.

I recommend: Gizmoszone offers plastic gears for customers interested in building robots. It uses a seasonal resin for its gears, which provides low friction and good bending strength.

Helical

With the ability to mesh in crossed orientation or parallel orientation, the helical gear has teeth cut at an angle slanted to the circumference of the gears. Its smooth, even design reduces noise.

I recommend: K2 Plastics has a large gear selection that includes helical gears.