E3D Revo Hot End is hailed as the best product since sliced ​​bread. Learn how it aims to improve the way we 3D print plastic.

The 3D printing space exists in two parallel universes: the professional one is locked behind the patent, where the printer works magically, but it costs hundreds of thousands of dollars at a time, and a space occupied by our consumers, they have to wait for decades The absurd patent expires to print anything but the simplest plastic.

This doesn't happen often, but thanks to the new Revo hot end of the British 3D printing company E3D, the consumer 3D printing field has reason to be excited. Let's delve into the 3D printing extrusion system to understand all the fuss.

If you imagine the concept of 3D printing as a baker sprinkling icing on a cake, it will be easier to understand the concept of 3D printing. Just as a baker manipulates a piping bag to print a name on a birthday cake, a 3D printer moves the nozzle to place plastic on the build surface.

In fact, the 3D printer extrusion system is very similar to the baker's piping bag.

Squeezing the frosting onto the cake by hand is no different from pushing the filaments out of the nozzle by an extruder. However, 3D printers are more complicated. Since plastic does not flow like frost at room temperature, every 3D printer must be equipped with heated nozzles.

This is essentially a high-tech piping bag consisting of an extruder that pushes the filament through a heated nozzle assembly while controlling the nozzle temperature and pressure to guide the filament flow.

As the consumer 3D printing industry relies on the pioneering work done by the open source RepRap project, consumer-grade 3D printers use the same DIY approach using off-the-shelf components.

Modern hot-end design is a good example of this phenomenon.

The traditional hot end consists of a nozzle screwed into the heater block, which in turn is heated by a separate cylindrical heater cartridge. The module is also equipped with a removable thermistor for temperature measurement. Finally, a separate thermal circuit breaker thermally isolates the hot end from the filament feed path, preventing it from melting on the way to the hot end.

Unfortunately, this is a very inefficient system.

There is an air gap between the heater block and the thermistor and the heater barrel, so effective heat transfer and accurate temperature control cannot be performed. The increased distance between these elements and the nozzle is also of no avail.

This results in the extrusion system being unable to control the nozzle temperature with any apparent speed or precision.

This is a major obstacle, because if you do not quickly change the nozzle temperature to keep up with the fluctuating filament flow rate, it is impossible to 3D print at different speeds and extrusion volumes.

In turn, this manifested itself as the 3D printing genie displayed by all consumer-level 3D printers, which has not yet been resolved to this day.

The welding industry solved this problem decades ago by combining these three elements into a single composite part to eliminate the air gap between the tip, heating element and temperature sensor. This soldering iron can heat up faster and can weld high thermal quality joints very easily.

The Revo hot end uses the same method, integrating the heater and thermistor into a smaller composite heater core. This solves many problems of the existing hot end.

Related: Learn the basics of successful welding

Fixing the slow nozzle heating is only the beginning, as the E3D Revo prototype demonstrated in the time it took to reach operating temperature, the time is a fraction of the competitive higher power hot end.

The higher thermal efficiency of the Revo heater core allows E3D to form a significantly smaller hot end. Its small footprint reduces the obstruction of component cooling fans to airflow. This therefore improves the print quality of complex parts that require bridging and steep overhangs.

Although some people may argue that the lower thermal mass of the Revo hot-end micro heater core makes temperature adjustment more difficult, modern soldering irons that use the same method also choose a lower thermal mass design.

E3D may make a difference here.

Efficient heater components do not need to store large amounts of heat. In fact, the lower thermal mass of the Revo hot end also allows it to cool down faster.

You want this hot end to cool down faster for good reasons. The reason is the tool-less nozzle replacement capability of E3D Revo. This is a godsend for a space where the frequency of nozzle clogging will only be exceeded by the destruction they release later.

So far, replacing the nozzle has been a difficult task, involving many heating and cooling cycles, and the nozzle needs to be thermally tightened at the maximum allowable temperature. Failure to do so will cause more congestion.

Related: How to upgrade your Ender-3 3D printer and resolve safety issues

On the other hand, the E3D Revo nozzle can be easily screwed on and unscrewed with your fingers. Of course, once the hot end cools down. Because the nozzle and heat shield are one unit, you don't have to worry about hot tightening and the associated risk of clogging or plastic leakage.

This is not just to prevent nozzle clogging.

Different nozzle sizes also allow you to strike a good balance between printing speed and quality. Want to print small objects with tighter tolerances? Break the 0.2 mm nozzle. Need to put down a lot of plastic in a short time? Please use 0.8 mm nozzle instead.

If the quick replacement nozzles of the Revo ecosystem really work as advertised, this will eventually make the tool replacement in the 3D printing field almost equivalent to the tool replacement of high-end subtractive CNC manufacturing counterparts.

When a temperature regulation failure causes a hot runway, the fire hazard is a real concern for 3D printers, which then causes the heating element to melt through the heater block and cause a fire.

The Revo hot end contains a positive temperature coefficient (PTC) heating element whose internal resistance increases as the temperature rises. As the nozzle heats up, this automatically reduces the power supply (heater wattage). On paper, this should significantly reduce the possibility of a 3D printer burning down the house.

The hot-end design with reduced thermal mass has a pleasant side effect, which is very light weight. The Revo hot end weighs only 30 grams, so it is possible to increase the acceleration value of the stepper motor without worrying about vibration.

This should allow the printer to reach its maximum speed for a longer time during the actual printing movement, while also reducing ringing and other quality-affecting 3D printing artifacts associated with high-speed shaking of the heavier hot end.

In terms of durability, the heater and thermistor cables are reinforced with steel armor strain relief. This should come in handy when dealing with a large number of printing failures that require prying out molten plastic from the hot end. Only this time, you are unlikely to accidentally pull the cable.

The UK-based company has been committed to the idea of ​​open source and has been releasing the engineering resources needed by the 3D printing community to modify its products and integrate them into other DIY and open source projects.

Although Revo Micro is a new hot-end design, Revo Six is ​​a direct replacement for the ubiquitous E3D V6 hot-end among a large number of consumers and DIY 3D printers. This means that almost everyone running E3D hardware can upgrade to the new Revo squeeze ecosystem.

Related: Beginner's Guide to DIY Voron 3D Printers

Revo will continue this tradition because E3D chose to open source the cold end interface. This should help 3D printing enthusiasts design their own heat sinks and mounts for Revo nozzles and heater cores.

In other words, in the near future, open source 3D printers (such as Rat Rig, HevORT, HyperCube, Voron series, etc.) can be easily updated to integrate these hot ends that may change the rules of the game.

On the other hand, E3D believes that rampant intellectual property theft forces it to apply and (in the future) apply for patents on unspecified aspects of the Revo extrusion system. However, it also promised to stop litigation against individuals, researchers, academia, and non-profit organizations using its design to promote 3D printing technology.

Since E3D's patent has not been published at the time of writing, it can only be guessed whether it is related to the unified heater core or the composite screw-in nozzle design with integrated heat shield.

Unfortunately, both of these hypothetical patents violated the company's commitment to avoid submitting "the most extensive and extensive patents that prevent people from also contributing to technological progress."

A unified heater core that combines a heater and a temperature sensor into one unit has been used in the welding industry for decades. At the same time, there is already a 3D printing patent for a fairly similar screw-in nozzle design with integrated thermal insulation.

We have contacted E3D to clarify the subject and will update this article when we receive their response. In any case, a potentially revolutionary extrusion system with four nozzle sizes, priced at $120, is definitely worth the hype before launch.

From objects to 3D printing, there are only five simple steps.

In his 15-year career, Nachiket has covered various technological beats from video games and PC hardware to smart phones and DIY. Some people say that his DIY article is an excuse to pass his 3D printer, custom keyboard and RC addiction as "business expenses" to his wife.

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