Let's talk diameters: 1.75 vs 2.85 filament

If you’re new to the 3D printing scene, or simply haven’t given it any thought; there are two filament options for FDM 3D printers. 1.75mm and 2.85mm (sometimes called ‘3mm’). These dimensions refer to the diameter of the material and will only work with filament paths designed for that standard. So, if you own a 3D printer, it’s important to know the difference. When 3D printers first began appearing, there was obviously a lack of filament suppliers around. The pioneers of the time used what they had, which were 3mm ABS welding rods. Once people began to switch to bowden setups to reduce weight, filament needed to be fed through tubing. The two available sizes were 2mm and 3mm (inner diameters). This led to 1.75 and 2.85 becoming standard.

Why is 1.75mm generally preferred?

• Finer filament control because of the lower cross-sectional area. Meaning better retractions and more success with the smaller nozzle sizes (0.25mm and below).  
• Have you ever had a PLA spool become brittle and then snap during a print? If you haven’t, then it’s likely you have the 1.75mm standard to thank for it. The thicker 2.85, does not handle the transition from spool to extruder as well as 1.75. Especially when wet. 
• Perhaps counterintuitively, 1.75mm filament is better for printing quickly. Maximum volumetric flow rate is considerably higher with 1.75 than 2.85.  

Some benefits of 2.85:

• A 0.2mm difference in diameter translates to a ±11.4% in flow rate for 1.75 but only ±7% for 2.85. Having said this, manufacturing tolerance has now got so good that it is rarely a factor. Most filament manufacturers work to a 0.05mm tolerance or better.
• The filament is stiffer. Which makes it a better choice for flexible filaments. With an extruder like Hemera XS though, you really won’t be needing stiffer filament. 
• With 2.85 usage on a steady decline, there are some deals to be had. Psst! …we’ve still got some 2.85mm stock at whopping 50% off!  

Why is the industry migrating towards 1.75mm filament?

Whilst there was a place for 2.85 when 3D printing took off, 2.85 has since become increasingly obsolete. Filament tolerances are better, extrusion systems are better (we’d like to think we had something to do with this!) and the general advancement of the technology has favoured 1.75mm filament.  

What about E3D?

 We said goodbye to 2.85mm when we released Hemera. To put it plainly there’s no longer enough demand for us to put the time and resources into creating 2.85 compatible products. There are currently no plans for a Revo variant either. That’s not to say we wouldn’t work with 2.85 ever again …if you’re an OEM looking for something specific, let’s talk! 

We’ve previously worked with Ultimaker to create a new CC core, suitable for 2.85mm filament.

We’ve noticed demand for 12v products drop off in a similar way. Most manufacturers are now using 24v (or higher) and we welcome that standardisation. Although, we are still offering Revo in 12v for those that need it. You can read more about 12v vs 24v in this blog.

My 3D printer uses 2.85mm filament, do I need to switch to 1.75? 

The short answer is no. At least not yet! At this point in time, there’s still a reliable supply of 2.85 filament. You just might have a more limited range of materials available to you. So, if you’re still happy with your 3D printer’s performance and the filaments that are available, there’s no immediate reason for you to switch.  

Two E3D (2.85mm) Titan Aeros are mounted together for dual extrusion on the Lulzbot TAZ Pro.

But if you’re not satisfied, or you’ve seen RapidChange Revo and want to make the conversion, you’ll need to replace your whole filament path. This includes your HotEnd, Extruder and any PTFE tube that connects the two. The best way to do this depends largely on your 3D printer and what features you’re looking for.  

If you’re stuck or would like more advice, we offer lots of ways to get help. The E3D Official Discord is full of 3D printing experts who can assist you with general 3D printing queries and our customer service agents are available to answer any questions you have about E3D products. You can also find a wealth of helpful technical info at the E3D Help Centre. 

Do you think there’s room in the market for both? Why not let us know on our social channels: Facebook, Twitter, Instagram or LinkedIn! 

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