Functional parts · 2026
3D printed gears and mechanical parts
Can a working gear be 3D printed?
Yes, if it runs with a light load, at low speed and without heat: gears and pinions for appliances, toys, blinds and models, pulleys, bushes, cams, hinges and racks. Nylon is the material that best resists wear; PLA and PETG are fine for prototypes and lightly loaded parts. For a spur gear, the maker needs the tooth count and the module (or the outside diameter), the face width and the shaft size. A small one costs about €10, excluding VAT and shipping. Fabrishare is a network of makers: post your project for free and get quotes within 24–48 hours.
Which mechanical parts hold up when printed, and which don't
A printed plastic part is not a steel one. It works well where the original was already plastic or where the load is small.
Printing works well for
- Plastic gears and pinions in appliances, toys, blinds and mechanisms that were already plastic
- Pulleys and sprockets for the belts of printers, robots and models
- Bushes and guides that turn or slide slowly on a metal shaft
- Cams, levers, hinges and stops in light mechanisms
- Racks and pinions for drawers, small flaps and models
- Prototypes to test a mechanism before making it in metal
Better in metal or bought ready-made
- Gears in drills, angle grinders and motors with high torque or high speed
- Gearboxes and drives under continuous load
- Ball bearings: the housing is printed and a standard bearing goes in
- Parts next to an engine or anything hot, above about 90 °C
- Safety mechanisms: lifting loads, brakes, catches holding weight above people
Which material for gears and parts that rub?
Rounded values; they vary with the filament brand and how the part is printed.
| Material | What for | Watch out for |
|---|---|---|
| PLA | Prototypes to check sizes and meshing | Softens around 55 °C; with constant friction it heats up and deforms |
| PETG | Lightly loaded parts used now and then | Softens around 70 °C and wears faster than nylon |
| Nylon (PA) | Gears, bushes and hinges in real use: the best at resisting wear | Absorbs moisture, and not every maker prints it |
| Carbon-fibre nylon (PA-CF) | Parts that have to be stiffer and keep their shape | More expensive; the fibre wears nozzles and fewer makers offer it |
| POM (acetal) | The plastic of many injection-moulded gears | Hard to print: it lifts off the bed and shrinks as it cools; few makers offer it |
| Resin | Small, precise gears for models and mechanisms with very little load | Standard resin is brittle: a knock snaps a tooth |
In a wear test at the University of Warwick on gears printed in five nylon-family materials, a plain nylon held up best; in another study, PLA gears failed from heat. If in doubt, say in the project what the part does and how fast it turns, and the maker will suggest the material.
What the maker needs to know
The file is enough. Without one, these details save rounds of changes. The formulas apply to standard spur gears (20° pressure angle, no profile shift):
| Part | What to measure or say | Tip |
|---|---|---|
| Spur gear | Tooth count, module or outside diameter, face width and shaft size | Outside diameter = module × (teeth + 2): 20 teeth at module 1 measure 22 mm |
| Two meshing gears | The same for both, plus the distance between their shafts | Centre distance = module × (teeth on one + teeth on the other) ÷ 2 |
| Shaft and fixing | Shaft diameter and how it grips: D-flat, keyway, spline or grub screw | A grub screw holds better against a metal nut set into the part |
| Timing pulley | Belt type (GT2, for example), tooth count, belt width and shaft | The type is usually printed on the belt |
| Bush | Shaft diameter, outside diameter and length | The maker tunes the hole to their printer so it turns without wobbling |
| Rack, cam or hinge | Rack module, cam travel, pin diameter | A photo with callipers and a sketch with dimensions beat any description |
Wear, lubrication and backlash
A printed gear wears faster than an injection-moulded one, especially under continuous load. It helps if it runs cool: at high speed, friction heats the plastic and softens it. If the mechanism has room, a slightly wider tooth than the original spreads the load better.
Lubrication: a grease that is safe for plastics. Some oils and greases attack certain plastics; if the device had grease from the factory, use the same type.
Backlash: two gears need a little play between the teeth so they don't jam, and FDM parts come out slightly larger than the design. The maker compensates for their printer, which is why a meshing part is worth a test print before the final one.
Prices: a small gear, a medium part and a run
Ballpark prices for the whole order, excluding VAT and shipping, worked out with the Fabrishare calculator in FDM. A small gear or bush, about 3 cm across, costs about €10 and takes about 20 minutes of machine time; a medium part about 6 cm across costs €7–€19. In nylon or with carbon fibre the price goes up, and if it has to be modelled, design is extra. Each maker gives the exact price in their offer.
| Part | Technology | Range | Typical |
|---|---|---|---|
| Small spare part (bracket, clip) | FDM | €6 – €17 | €10 |
| Medium case or cover | FDM | €7 – €19 | €12 |
| Run of 100 small parts | FDM | €219 – €585 | €365 |
Test part first, then the run
- 1
A test part
In PLA or PETG, quick and cheap, to check sizes, meshing and that the shaft fits.
- 2
Adjustments
Whatever doesn't work (a tooth that rubs, a tight shaft), the maker fixes in the model. If it will be edited, STEP is better than STL.
- 3
The real part
In the final material: usually nylon if it rubs or carries load.
- 4
The run
If you need several the same, approve one before ordering the rest. For reference, 100 small FDM parts come to about €3.65 each.
Other functional parts
Spare parts
The general guide: which spare parts can be printed, materials and how to order them.
3D printed spare partsAdapters
Parts that join two things that don't fit: dust extraction, pipes, mounts.
Custom adaptersPrototypes
Testing a mechanism before making it in series or in metal.
Rapid prototyping with 3D printingSmall batches
From dozens to a few hundred identical parts, at a lower price per part.
Small batch 3D printing
How to order your mechanical part
- 1Post your project for free with the file or the part's details (teeth, module, shaft), photos with callipers and what it's for.
- 2Makers in the network send you their offer with price, material and lead time within 24–48 hours.
- 3You compare, choose, and the maker prints it and ships it to you.
Frequently asked questions
How much does it cost to 3D print a gear?
A small FDM gear, about 3 cm across, costs about €10 (€6–€17) and a medium part about 6 cm across €7–€19, excluding VAT and shipping. Nylon or carbon fibre costs more, and modelling is extra. Each maker gives the exact price in their offer.
What is the best material for a 3D printed gear?
Nylon (PA) for real use: it resists wear best. With carbon fibre (PA-CF) it's stiffer. PETG for lightly loaded parts and PLA only for prototypes. POM, the plastic of many moulded gears, is hard to print and few makers offer it.
Will a PLA gear last?
For a prototype or a mechanism that barely moves, yes. Under constant friction it heats up and softens (around 55 °C): for real use, nylon or, if the load is small, PETG.
How do I find a gear's module?
Count the teeth and measure the outside diameter with callipers: for a standard spur gear, module = outside diameter ÷ (teeth + 2). 20 teeth and 22 mm give module 1. Modules come in standard values such as 0.5, 1, 1.5 or 2. If it meshes with another gear, send that one's details too.
Can a gear from a drill or a food mixer be printed?
From a drill or an angle grinder, no: too much torque and speed. From a lightly loaded device whose original gear was plastic, sometimes yes, in nylon, but it wears: ask for a test part and expect it may not last as long as the original.
What about bearings?
Ball bearings aren't printed: the part that holds them is printed and a standard, inexpensive bearing goes in. A simple bush turning slowly on a shaft can be printed, ideally in nylon.
Should printed gears be greased?
It helps, with a grease that is safe for plastics: some oils and greases attack certain plastics. If the device had grease from the factory, use the same type.
I don't have a file. Can someone design it?
Yes: a maker who designs can model it from the old part, photos with callipers or the gear it meshes with, and the design is quoted separately. If it's broken, keep the pieces: the remaining teeth give the module.
Can they make a batch?
Yes. The usual way is to approve a test part and then order the run. For reference, 100 identical small FDM parts come to about €3.65 each, excluding VAT and shipping.