Best Filament for Gears – How to 3D Print Them
Reading Time: 12 minutes There are plenty of people out there that 3D print gears, but it can be an issue deciding which filament to use for them. This article will guide you on what the best filaments for gears are, as well as how to 3D print them.
If this is what you’re looking for then keep on reading through to learn some useful information about 3D printed gears.
Are 3D Printed Gears Strong Enough?
Yes, 3D printed gears are strong enough for many common mechanisms and for various uses. Materials like Nylon or Polycarbonate are preferable for printing gears, as they are stronger and more durable. 3D printed gears can be preferred over metal ones due to their lighter weight, for robotics projects or replacements.
Furthermore, designing and printing your own parts can save you a lot of time, since ordering replacements for some mechanisms can take a while.
On the other hand, 3D printed gears are most likely too weak for heavy-duty machinery, regardless of the type of filament you are using, unless you are printing them at a professional center that uses very strong materials.
Here is an example video of a user who successfully replaced a damaged plastic gear for a radio-controlled car with a 3D printed nylon filament one.
Depending on what you intend to use the gears for, different materials will yield better results, and I will go through suitable materials for 3D printing gears in the following sections.
Can PLA Be Used for Gears?
Yes, PLA can be used for gears and it has been working successfully for many users that 3D print them. One example of 3D printed gears successfully made out of PLA is from a Geared Heart 3D print that contains moving gears. It has over 300 Makes, many of them made from PLA. For simple gear models, PLA works well.
In this case, users made the gears from filaments such as CC3D Silk PLA, GST3D PLA or Overture PLA, which can be found on Amazon. Some PLA types, colors or composites perform better than others, and I will come back to these in the following section.
PLA is not the strongest or most resilient material when it comes to durability and torque (rotational force), and it deforms at temperatures of over 45-500C, but it does perform surprisingly well for its affordable price, and it is a very easy to acquire material.
Have a look at this video that tests the strength and durability of lubricated PLA gears.
Best Filament for 3D Printing Gears
Polycarbonate and Nylon appear to be the best filaments for 3D printing gears at home, due to their durability and strength. Polycarbonate has superior mechanical properties. However, Nylon is much more accessible and versatile, which is why it is often regarded as the best filament, since more people use it.
Below is a more detailed description of these filaments, as well as the very popular PLA.
1. Polycarbonate
Polycarbonate is not a common filament, mainly because it is a bit more expensive and you need a printer whose nozzle temperature can reach 300°C. However, it can still be categorized as a standard filament, as many people use it for their projects at home.
The Polymaker PolyMax PC is a high quality brand of filament that you can get from Amazon. It’s easier to print than a lot other Polycarbonate filaments out there according to many reviewers.
One user described it as being easy to work with, even on an Ender 3. It’s a composite PC so you do give up some strength and heat resistance for a better ability to print it. The balance of this was done really well by Polymaker, and you don’t even need a special bed or enclosure to get great prints.
There are numerous types of Polycarbonate filament, which vary depending on the manufacturer, each performing slightly differently and having different requirements.
This filament is very strong and withstands temperatures of up to 150°C without deforming. If you need to print a gear that you know will get hot in the mechanism, then this might be your best choice of material.
On the other hand, it is more difficult to print, and it requires high heat from both the nozzle and the bed.
2. Nylon
Nylon is perhaps the most popular choice for 3D printing gears at home, and it is one of the best choices out of the mainstream and affordable filaments on the market.
This material is strong and flexible, and has high heat resistance, meaning it can perform without deforming at temperatures of up to 120°C
It is also durable, with one user mentioning that a replacement gear 3D printed in Nylon lasted over 2 years. It is more expensive than PLA, however, and it is a little more difficult to print, but there are many tutorials and instructions online that can help you print durable gears.
A subcategory of nylon filament is carbon fiber reinforced nylon. This is supposedly stronger and stiffer than normal nylon filament, however user’s opinions are mixed in this case.
I’d recommend going with something like the SainSmart Carbon Fiber Filled Nylon Filament from Amazon. Many users love its strength and durability.
Some popular brands that offer nylon and carbon fiber nylon filaments are MatterHackers, ColorFabb and Ultimaker.
Another great Nylon filament that you can get for 3D printing phone cases is the Polymaker Nylon Filament from Amazon. It’s hailed by users for its toughness, easiness to print and aesthetics.
One drawback of Nylon is that it has high moisture absorption, so you must make sure you store it properly and keep it as dry as possible.
Some people recommend printing straight from a humidity-controlled storage box, such as the SUNLU Filament Dryer from Amazon.
3. PLA
PLA is arguably the most popular 3D printing filament in general, and this makes it widely accessible both in terms of price and finish diversity.
In terms of gears, it performs well, although it is not as strong or resistant as nylon. It softens when exposed to temperatures higher than 45-50oC, which is not ideal, but it is quite durable nonetheless.
As previously mentioned, you can go with some great PLA filament such as:
Similar to Nylon filament, there are different variations and composites of PLA, some stronger than others. The video below looks at different materials and composites and how they react to torque (or rotational force), and it compares their strength, starting with different types of PLA.
The video below looks at the durability of PLA after 2 years of daily use (with this Fusion 360 File used as an example).
Many people use PLA for less complex projects (such as the Geared Heart mentioned above), and for this kind of projects this filament is a great choice.
Sometimes, people would print temporary replacement gears out of PLA for more complex machinery, with a successful outcome.
4. PEEK
PEEK is a very high-level filament that can be used for 3D printing gears, but it does require a specialist 3D printer and a more professional setup.
One of the main properties of PEEK is just how strong it is, currently being the strongest filament on the market you can buy and 3D print at home, though getting the printing conditions right can be difficult.
Since PEEK is used in the aerospace, medical and automotive industries, 3D printing gears out of this material would give you exceptional results. However, this is a very expensive, costing around $350 for 500g. It’s also difficult to print at home, which is why it might not be an ideal choice.
Have a look at this video that gives an introduction into PEEK.
You can check similar ones for sale at Vision Miner.
How Do You Make 3D Printed Gears Stronger?
To make your 3D printed gears stronger, you can calibrate your printer, print the gears face-down to avoid having supports, adjust the printing temperature to make sure the filament bonds well, adjust the infill settings, and make less teeth, so each tooth can be printed thicker and stronger.
Calibrate Your Printer
As with any print, calibrating the printer properly should help you make your 3D printed gears stronger, as well as more dimensionally accurate.
Firstly, be careful about bed levelling and the nozzle distance from the bed, so you can get a strong first layer and good layer adhesion for your gear.
Secondly, calibrate the E-Steps and Flow Rate so you can have the right amount of filament flowing through the extruder and avoid blobs or gaps in your 3D printed gears, which can compromise its integrity. Here is a video explaining how to do this calibration.
Print the Gear Face Down
Always print your gears face-down, so that the teeth of the gears are touching the built plate. It produces a gear with stronger teeth since the layer adhesion is more secure. It also reduces the need for supports, which when removed can damage the integrity of the gear.
Here is a video explaining printing orientation more in-depth.
If you have a gear with a mounting, always print the gear at the bottom, with the mounting on top, as shown in the video below.
Calibrate the Printing Temperature
You want to find the best temperature for your filament to melt properly and stick to itself. You can do this by printing a Temperature Calibration Tower from Thingiverse.
There is a newer technique to setting up a temperature calibration tower through Cura. Check out the video below to see how you can do this for your own 3D printer.
Raising your temperature without a calibration test can be done to melt the filament more and make layers bond better. Usually, increasing the temperature in 5-10°C works well if you are experiencing such issues.
This can be paired with decreasing or removing cooling altogether, for better layer adhesion. If this does not work to make your gears stronger, however, you should do a calibration test.
Adjust Infill Settings
Generally, you need an infill value of at least 50% to achieve a good level of strength for the gear but the value can differ depending on the infill pattern.
Some users recommend 100% infill for smaller gears, while others suggest that anything over 50% works, and a high infill percentage will not make a difference. It has been suggested that the Triangle infill pattern is good to use as it provides strong internal support.
One infill setting that will make your gear stronger is Infill Overlap Percentage, which measures the overlap between the infill and the walls of the model. The higher the percentage, the better the connection between the walls and the infill.
The Infill Overlap setting is set at 30% by default, so you should gradually increase it until you see no more gaps between the infill and the perimeter of your gear.
3D Print Gears with Fewer Teeth
A smaller number of teeth on a gear means larger and stronger teeth, which, in turn, means a stronger overall gear. Smaller teeth are more prone to breaking, and they are more difficult to accurately print.
The thickness of the teeth of your gear should be 3-5 times the circular pitch and increasing the width of your gear proportionally increases its strength.
If your project allows it, always choose the minimum number of teeth required. Here is a more detailed guide on how to approach the design of gears for maximum strength.
There’s a really cool website called Evolvent Design where you can create your own gear design and download the STL to 3D print.
How Do You Lubricate PLA Gears?
To lubricate gears, you should use grease or oil to cover the gears so that they rotate and slide easier. Popular lubricants for 3D printed gears include lithium, silicone or PTFE based ones. They come in applicator bottles and sprays depending on your preference.
For PLA, for example, it’s best to choose a lighter lubricant, although the above-mentioned greases have been widely used as well, with satisfying results.
Different types of lubricants there have different ways to apply them. Lithium grease is applied directly on the gears, while PTFE usually comes in a spray form. Apply the lubricant of choice and spin the gears to make sure the rotation is smooth.
Some lubricants with good reviews include Super Lube 51004 Synthetic Oil with PTFE, STAR BRITE White Lithium Grease, or even cosmetic Vaseline. Super Lube is probably the more popular option for 3D prints though, having over 2,000 ratings, 85% being 5 star or above at time of writing.
Many 3D printer users use Super Lube for a range of parts such as hinge, linear rails, rods and more. This would be a great product to also use for 3D printed gears.
You should clean and lubricate the gears periodically to ensure smooth mechanism operation (have a look at this guide for more information on the cleaning process of printed gears).
Can You 3D Print a Worm Gear?
Yes, you can 3D print worm gears. People have been using various materials for worm gears, with Nylon being the most popular choice, as it is stronger and more durable, followed by PLA and ABS, which perform much better when lubricated. Users recommend printing them at a 450, to avoid excessive stringing and supports.
One user also used PETG to print a worm gear for their car wipers, which has successfully worked for over 2.5 years.
Here is a video that tests the durability and strength of both dry and lubricated worm gears made from PLA, PETG and ABS, at high speeds.
Although very much possible, designing and printing worm gears correctly may be a little difficult, as you need precision and durability.
Furthermore, lubricating the gears might also pose some difficulties, as the lubricant tends to be removed in the rotational process, leaving the gear unprotected. This is why Nylon is usually the first choice for worm gears, as it does not need additional lubrication.
Can You Resin 3D Print Gears?
Yes, it’s possible to resin 3D print gears successfully and get some use out of them. I’d recommend for you to purchase special engineering resin that can withstand a lot more force and torque as compared to normal resin. You can also mix in some flexible resin to make it less brittle. Avoid curing parts too long.
The video below by Michael Rechtin is a really cool experimental testing out a 3D Printed Planetary Gear Box using both resin and FDM 3D printing. He used Tough PLA & ABS-Like Resin for this test.
One user did mention that their experience of 3D printed gears was that resin gears can actually be stronger than FDM gears. They had two applications where the teeth of the FDM 3D printed gears sheared off, but ran good with tough resin 3D prints.
The gears lasted around 20 hours before snapping or deforming. They ended up switching to pulleys and belts for better results in their particular project, which has been running successfully for over 3,000 hours.
