E3D Hemera - A Next Generation Extrusion System - 3docity

E3D Hemera - A Next Generation Extrusion System

Blog originally written and supplied by E3D Online.


E3D Hemera – formerly Hermes – is the best extrusion system we’ve ever made. It combines our market leading V6 hotend with an all new filament drive to form a highly responsive direct drive extrusion system – providing unrivaled performance with flexible filaments. Hemera is also available as a bowden extruder.

Featuring a dual-drive, hardened stainless steel drive train with a fully constrained, super-short filament path and an E3D-V6 Hot-Side, E3D Hemera provides an unrivalled precision extrusion experience: excellent control over stops and starts; greatly reduced stringing and blobbing; and greater filament traction means slipping and grinding are a thing of the past. We print flexibles at 50mm/s.

Upgrade almost any extrusion-based 3D printer on the market today, easily. Buy E3D Hemera now.

Wait, what did you do with Hermes?

You’re probably wondering why at the last minute everything that you were expecting to be called ‘Hermes’ is now called ‘Hemera’. Unfortunately, less than 24 hours before launch, we received a legal challenge from a company much larger than us, and with significantly more legal resources. They objected to us naming our product after a Greek god from the Mycenaean era, as they feel that name belongs to them.

Unfortunately we don’t have the time or resources to resolve this through a long legal process and we just want to get on with making incredible extrusion systems. Therefore we’ve had to undergo a rapid unscheduled rebranding, and have settled on Hemera, a somewhat less fashionable Greek god, yet still in keeping with our other mythological names, and our first female one too.

Please do excuse us if some of the content is slightly less polished than usual, it’s been a long hard night. If you see any instances of the old name hanging around please do let us know too. Thanks in advance for your understanding.

Dual Drive – Push Harder

For E3D Hemera, we opted for a dual-drive arrangement which provides a huge boost in grip over single drive systems. We are able to push filament with up to 10kg of force. The secondary gear shaft is on a moveable, sprung idler which allows the user to adjust filament tension. All the gears are hardened stainless steel.

Sharp teeth – with a round bottomed profile – provide excellent grip and strongly resist filament debris wedging into the drive gear and in almost all cases it’s self-cleaning as any debris simply falls off the teeth. (Look familiar? You may remember this self-cleaning tooth profile in the Titan extruder.)

hemera gear

We achieve this profile by individually CNC cutting each tooth, allowing us to provide the round-bottomed root, with a tooth that curves upwards to a robust, sharp tip.

gear hemera

As a result of opting for an all-metal hardened stainless steel drivetrain, we were able to reduce the size of the gears. This enables the drivetrain to fit within the frame of a Nema 17 stepper motor – more on compactness in the next section. With the drive train being made from hardened stainless steel, we can maintain lubrication-free operation of the Hemera gearbox. For bearings we make use of an igus® bushing and shielded ball-bearings. A dry-running system, as we know, means minimal user-maintenance and also prevents filament debris from sticking to a greasy drive train.

When designing Hemera’ dual-drive hobbs, we took a ground-up approach starting with a specification of dual-drive, researching and testing material combinations and implementing our tooth profiles. Dual drive is an established concept within the industry (going all the way back to 2011 with Steves Extruder used on the SeeMeCNC H1) and it is clear that dual-drive provides considerably more grip when compared to single drive systems. Fundamentally, the entire extrusion system is just better.

Compact, Integrated System

We set out to develop a compact extruder and HotEnd system with a reduced part-count. Hemera is a system of components designed to work seamlessly together as a single product.

Hemera has a custom motor, based on a NEMA 17 frame, with our own bespoke faceplate which allows the motor itself to be part of the extruder housing, this lowers part count, makes assembly easier, and results in a compact system.

gear and stepper motor hemera

Unparalleled Flexible Performance

Hemera constrains your filament like no other extrusion system. You won’t truly ‘get’ the impact of the optimised constraint that Hemera provides until you’ve printed flexibles with it. But trust us – the performance is second to none and also has a significant impact on printing normal materials such as PLA or PETG.

A flexible example we like to show is the famous “retraction performance test” model by MAKE (a model with many retractions, short stop/start extrusions, and travel moves) we are able to show off incredibly defined results with no stringing or oozing, indicating how unbelievably responsive the system is. Just look at this TPU print:

hemera tpu example

If you were impressed, then wait until we tell you that we printed the TPU print using typical PLA settings. We didn’t change anything except the filament. 50mm/s with a 0.2mm layer, with a 0.4mm nozzle.

How did we achieve this wizardry? Firstly, Hemera was designed to be compact which allows us to attain a very short distance from drive-wheels to melt-zone. This has a number of benefits, primarily reducing the length of filament under compression when being pushed into the melt zone, improving responsiveness.

hemera compared to titan

Secondly, we carefully toleranced all the components after the drive gear. There is a clearance gap between drive gears and heatbreak of approximately 100µm. The filament is tightly constrained in the heatbreak with only 250µm of clearance (enough to allow for slight inconsistencies in filament, but not so much that we introduce a big filament-spring into your system!)

hemera demo

These two improvements together mean that the filament has only one place to go – into your nozzle, and that when you apply a force – it responds.

An additional benefit of this arrangement is that there are zero transitions after the drive gears, filament proceeds directly to the melt. This ensures reliable operation.

Custom Motor

We set out to develop a compact extruder and HotEnd system with a reduced part-count. Hemera is a system of components designed to work seamlessly together as a single product.

Hemera has a custom motor, based on a NEMA 17 frame, with our own bespoke faceplate which allows the motor itself to be part of the extruder housing, this lowers part count, makes assembly easier, and results in a compact system.


The T-Slots on the custom motor faceplates allow for easy mounting solutions to pre-existing machines, as well as providing a more compact, stable platform for printer manufacturers to integrate onto their machine.

Each side of the motor has 4 T-Slots which accept standard M3 square nuts. The outward faces of the T-slots have been machined flat to allow for rigid, precise and orthogonal mounting. One side can be used for mounting to the carriage, leaving the opposing face free for mounting whatever you need, part cooling fans, bed levelling probes, or other accessories.

hemera bl touch mounting

A new heatsink with optimised airflow

The heatsink isn’t just a visually striking aspect of Hemera (or inspired by Sanjay’s hair). As a result of in-depth testing with a hot wire anemometer setup, we have optimised the airflow of the die-cast fins. Airflow is directed up and away from both the HotEnd and the heated bed, meaning airflow does not disrupt the print envelope. This reduces the risk of warping and uneven stresses forming in the printed part.

hemera heatsink demo

User-centered design

All interaction with Hemera is from the top. To set filament tension the user simply twists a thumbscrew and a cam slider mechanism with a captive nut compresses a spring and loads the idler. Filament tension is increased by rotating clockwise and decreased by rotating counterclockwise.

Hemera is designed to auto-load filament exceptionally reliably, no matter what you throw at it. With the drive wheels turning, you can literally drop filament onto the hobbs and it will be sucked in, and you will be ready to print.

Although we have implemented self-cleaning drive-teeth and made it so no lubrication is required, there may one day be the need to disassemble Hemera for maintenance. If maintenance is required, the internal mechanisms are easily accessible by removing the fan, and undoing the two faceplate screws. Full access is available to clean and replace parts even while filament is loaded. When you pop off the faceplate the filament, idler and spring all come along too, as one neat assembly.

Quality control considerations

Here at E3D, we strive for excellence by putting emphasis on developing rigorous quality control. As part of our focus on traceability, we are laser engraving QR codes onto the Hemera motor, allowing us to tie the QC data we already collect, to the unit in your hand.

In order to quality control the complex 3D geometries of the Hemera heatsink and motor we purchased dedicated new and upgraded inspection equipment that combines optical measurement and probing.

Eventually, we aim to have this serialised data, along with sensor and heater data available to every customer via our website.

e3d hemera

Direct And Bowden

The Hemera cold side (heatsink & extruder) is compatible for use in both direct and bowden modes. In direct, we make use of an E3D-V6 hotside (with a custom heatbreak).

In bowden, we simply replace the hotside with the Hemera bowden adaptor (or “bowdaptor” as we like to call it).

Note that the cooling fan is required in direct mode, but not in bowden mode.

The bowdaptor allows you to attach a length of PTFE tube via the same collet and collet clip as you’d come to expect with the rest of our ecosystem.

With Hemera our goal was to raise the performance bar of extrusion and hotend systems. We have the advantage of scale, and so have also paid heavy attention to the manufacturing processes being used to keep costs low. Die-casting of the heatsink and motor faceplates are incredibly efficient ways to produce precise aluminium parts in high volumes. We touch this up with a minimal amount of post-machining to achieve a perfect balance of cost and quality (whilst also getting some sexy bare metal highlights.)

E3D ecosystem compatibility

Hemera features a new heatbreak with an M4 thread on the coldside to improve heat transfer.

The flange on the heatbreak ensures a precise mate between the heatbreak and the heatsink. This guarantees perfect positioning of the break between the drive gears, giving that fantastic constraint.

The hot side makes use of the standard M6 thread which maintains full compatibility with the E3D ecosystem of nozzles, heater blocks, temperature sensors, and heater cartridges.

E3D Hemera, is a powerful, advanced extrusion system, we truly believe is the best product that we’ve ever brought to market and can’t wait for you to get your hands on it.

We’ve spent a huge amount of time ensuring that this product is as compatible, universal and user friendly as it can possibly be for the end

user. As such, to make things as easy as possible for you guys, we’ve collaborated with some of the industry’s most loved content creators (MakerNoob, CNC Kitchen, Toms3DP, Maker’s Muse & Ivan Miranda to name a few) to bring you videos for the most popular printers on the market.


How much does Hemera weigh?

In a direct drive configuration E3D Hemera weighs 388g

In a Bowden setup Hemera weighs 327g

Can I use it on a delta printer?

Is Hemera compatible with my 3d printer?

When will there be a lower profile (Shorter) motor available?

At this time alternative motors designs are in review and are to be confirmed. The custom E3D Hemera motor is specced to give you optimal, high performance printing experience, and provides enough force for even the SuperVolcano.

Can Hemera be used on the Tool Changer?


Do you supply mounts for the Hemera?

Mounts for some of the more popular printers can be found within our Hemera documentation.

However if a mounting option for your printer is not available Hemera you could refer to websites such as Thingiverse.com for someone who’s designed one already.

Alternatively mounting dimensions are detailed within the following data sheet if you wish to design your own. See our data sheet for more information.

Will Hemera be supplied with a part cooling Fan.

Hemera is not be supplied with a part cooling fan however a recommend part cooling fan can be purchased as an additional item here

Alternatively you can use a 40x40x20 mm Blower Fan with a printed duct mount.

The 40x40x10 fan can be purchased via the following link

The stl file for the duct can be found here

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