1.75mm vs 3mm filament for 3d printing: their pros and cons!

You may have recently entered the world of 3d printing and still don’t know that there are two standardized diameters of filament. It is also possible that you bought a used printer from someone who built their own machine 10 years ago when the most used filament diameter was 3mm. In any case, it is useful to know that both diameters are available on the market. Knowing their pros and cons is crucial for you to decide if you are planning on getting a 3d printer.

Although the standard nowadays is 1.75mm filament, many manufacturers still produce 3mm filament. Opinions about which one is best come in all flavors, so you should learn about each one and decide on your own.

If you do not want to dig deeper into the subject, I recommend you get a 3D printer that is compatible with 1.75mm filaments. In fact, unless you have a very specific purpose in mind that requires a 3mm nozzle, I always recommend going with the 1.75mm standard. The standard for the market is clearly defined, and some experts also argue that it will become more difficult and expensive to get your hands on a less popular 3mm spool of filament with each passing year.

I lay out the most important advantages and disadvantages of each filament in the following table.

Which filament diameter is the most popular in 3d printing?

The most popular diameter used in 3d printing is definitely 1.75mm. The percentage of users that use this diameter grows steadily every day, twisting the arm in favor of the thinner filament. Virtually every home 3d printer manufacturer sells exclusively 1.75mm compatible machines.

If you ever encounter a problem with your printer (which you will), be it its hardware, firmware or any hardware or software component, you can easily look for the solution in any forum on the web (and on 3dsolved.com 😀 ). That is if and only if you have a 1.75 mm printer. Otherwise, the help you get will be very little and probably outdated.

Additionally, all improvements and innovations in the industry are being created almost exclusively with 1.75mm printers in mind.

Advantages and disadvantages of 1.75mm filament for 3d printing

Advantages of 1.75mm filament for 3d printing

As previously mentioned, the market has decided to choose this diameter as the standard for the hobbyist or desktop 3d printer market. Nonetheless, it is interesting to know the reasons that were behind this trend.

Higher printing speed

In order to print an object, it is obviously necessary to melt the filament in order to place it accordingly to the digital version of the object. This means that all of the plastic travelling across the hotend has to reach the working temperature. The heat generated in the heating block is transmitted to the nozzle and the barrel towards the filament in a simple process of heat conduction. The speed that heat is transmitted from the periphery of the filament to its central fiber depends mainly on the type of plastic and its geometry. Therefore, a thicker filament takes longer to reach the same core temperature.

As it takes less time to melt, the flow rate of filament through the nozzle can be increased, which translates into an increase in printing speed.

Less power required

If we analyze the cross-section of both filaments, we will see that the area of ​​the 3mm filament is almost 3 times greater than that of its thinner counterpart. This causes the pressure in the nozzle to also multiply comparing to the 1.75 mm filament. To achieve this pressure level, the extruder must generate enough force, otherwise, the stepper motor will start losing (skipping) steps.

The 1.75mm filament requires less pushing force. In other words, the machine is going to work fine even with smaller, less powerful stepper motors.

Extruder size reduction

As we just said, extruding a thicker filament requires more power. To solve this, the first manufacturers used more powerful motors to push through the 3mm filament, with the negative consequence of an increase in the weight and volume of the extrusion system. In direct-type extruder systems, this additional mass generates excessive inertia that produces unwanted vibrations. These are transmitted to the object, resulting in an awful wobble along with it.

The 1.75 mm filament can be used with an extruder without a gear reduction, using a lower torque (and therefore smaller) stepper motor.

Higher Market availability

Due to the fact that 1.75mm diameter filament is the new standard, it is easier to find stock for this diameter at any filament store. The availability of colors and materials is also higher, as many filament manufacturers do not produce 3mm spools. Resellers also prefer to keep a bigger 1.75mm stock, especially of PLA, as it is the most widely used filament of all.

Disadvantages of 1.75mm filament for 3d printing

Although there are many reasons to choose the 1.75mm filament, there are also some disadvantages:

It has a smaller dimensional tolerance

The number “1.75 mm” is a nominal value, but in fact, the filament has a tolerance margin in its dimensions. Some sections may be thinner, and others thicker. Even the cross-section of the thread is allowed to be an ellipse instead of a circle. The quality that most manufacturers achieve nowadays is increasingly higher, but there is no 100% perfect filament.

A variation of + – 0.1mm represents a higher percentage of error in a 1.75 mm filament when compared with the same deviation in 3 mm. For this reason, cheaper filaments tend to cause jams (due to oversize) or under extrusion (due to minor measurements) during printing.

Regardless of this disadvantage, manufacturers have managed to increasingly improve the maximum tolerance of their filaments. The most extreme case is Prusament, where they provide a QR code to review the quality of each individual spool of filament that they produced. According to the photo below, that spool’s tolerance was well within the diameter of a human hair.

It tends to get tangled

As the 1.75 mm filament is thinner and lighter, if we lose the tip of the filament when handling the coil, it can get tangled up with itself. The “knot” can be difficult to see, and most users will start the print without knowing that trouble is imminent. After a while, the filament locks up, which spoils the printing and can seriously damage the printer.

It bends easier

When printing objects with flexible filaments (such as TPU), using a 1.75mm filament spool can lead to more issues compared to a 3mm one. Upon reaching the nozzle area, the filament increases the tension along its axis. This compression will cause the filament to bend in any free area between the barrel and the extruder. If the printer is of a Bowden type, the problem increases even more.

Advantages and disadvantages of 3mm filament

Advantages of 3mm filament for 3d printing

From what we’ve seen so far, it appears that 1.75mm filament is way better than 3mm, but there are some advantages when printing with a thicker filament.

It absorbs less moisture:

Although you might think otherwise, the thicker filament is less affected by moisture. As it has a lower surface/volume ratio, and its exterior is saturated earlier, preserving its interior.

Allows for increased extruding flow

In combination with a wider nozzle, the 3mm filament can be extruded at a very high flow rate. By setting proper print parameters, an increase in print speed can be achieved on very large objects. Check out the following video, where an object is printed by using a 2 mm nozzle.

It would be impossible to print such an object with 1.75mm filament. For starters, the diameter would be less than the diameter of the nozle, meaning that it would pass through without being compressed by the nozzle cilinder. This would lead to a huge loss of accuracy.

It is more suitable for bowden system:

The main drawback of using a printer with a Bowden-type system is that the filament tends to bend or compress along its way, whereas with a thicker filament, it is more difficult for this to happen.

Disadvantages of 3mm filament for 3d printing

It should come as no surprise that the less popular diameter choices also come with their disadvantages. If not caused by mere bad luck, the market has chosen to almost abandon this diameter because of the following reasons:

Usually more expensive:

Production costs are higher when manufacturing 3mm filament. This happens because manufacturers are producing more and more 1.75mm filament, and there is a more competitive market. This is not caused by some inherent characteristic of this diameter, but by simple economies of scale.

Increased oozing

The melt volume is greater in this type of hotends, meaning that the tip of the nozzle drips much more at the beginning of the print. It is also more difficult to set correct retraction speed and distance parameters. You may have experienced something similar if you ever printed an object with a larger nozzle (0.8mm for example).

Lower dimensional accuracy:

Although this is defined by the width of the nozzle, we could not use a 0.1 nozzle in combination with a 3 mm extrusion system, since the pressure in the hotend would be too high, even for extruders with a reduction gear. This translates to most nozzles having a wider diameter, which is the actual cause for the loss of precision.

Why are there two filament diameter standards in 3d printing?

A few years ago, 3d printing was a technology reserved for universities or researchers. When they had to choose the input material for their machines, they chose to go the 3mm route, because of the simple fact that this diameter was already available. 3mm spools were used to weld ABS parts made by means of other technologies, such as plastic injection, so early designers took something that already existed and built their machines around it.

As soon as the RepRap project was born, many 3d printer manufacturers and makers noticed that using thinner filament could optimize the extrusion capabilities of their printers while reducing the size of many components. Since then, 1.75mm filament has become the standard in 3d printing, although most filament manufacturers continue to provide their customers with both sizes.

Can you print 3mm filament on a 1.75mm machine?

If you bought a 3mm spool by mistake, the first thing you should try is to return it to the seller. If the seller decides not to exchange the spool for another, you can try selling the filament to a 3mm user. This is not very useful advice, since you are probably wanting to know if you can use your 3mm spool with your 1.75mm printer.

The 3mm filament doesn’t fit into the holes of a 1.75mm extruder, so you couldn’t use it even if you tried. If you have some strange and obscure 3d printer where the 3mm filament does fit, you should still not use it. Since the entire machine was designed to be used with 1.75mm filament, you have a high risk of permanently damaging some component.

Is 3mm diameter filament actually 2.85mm?

If you measure the diameter of a 3 mm filament using a caliper, you will notice that it actually measures around 2.85 mm. This is mostly due to the fact that PTFE tubes have an internal diameter of 3mm (nominal), which would cause the filament to get stuck if there is interference somewhere along the path. If you own a 3mm 3d printer, check out the manufacturer’s datasheet to correctly set this parameter in the slicers software. Changing the filament diameter in the slicer is also equivalent to changing the flow rate.

Can you convert a 3mm printer to be compatible with 1.75mm?

It is very possible to transform your 3mm printer into a 1.75mm one. In fact, it is easier than I thought until recently. You only have to change the components of the extrusion system, from the extruder to the hotend.

Check out the following video were the amazing Thomas Sanladerer goes through this process in an easy step by step tutorial.

Check out our recommended products section

We created a recommended products section that will allow you to remove the guesswork and reduce the time spent researching what printer, filament, or upgrades to get, since we know that this can be a very daunting task and which generally leads to a lot of confusion.

We have selected just a handful of 3D printers that we consider to be good for beginners as well as intermediates, and even experts, making the decision easier, and the filaments, as well as the upgrades listed, were all tested by us and carefully selected, so you know that whichever one you choose will work as intended.

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