One of the main trends of this year in home and office 3D-printers is the usage of all-metal nozzles or so-called “hotends”. The E3D company from Great Britain released sixth version of its all-metal hotend in May 2014, giving their customers a choice of three possible variations: with bowden for 3mm plastic, with direct intake of 3mm plastic and universal one for 1.75mm plastic.
For our testing we received universal version for 1.75mm plastic from the E3D. The nozzle is delivered in disassembled form, packed in sealed envelope. Inside the packaging you can find: massive aluminum heatsink, which is now more compact in comparison with fifth version, heatsink has molded (in 5th version it was 3D-printed) case from plastic for cooler mounting, stainless steel heatbreak, heating unit, 0.4mm brass nozzle, fluoroplastic tube (there was no such tube in fifth version), ceramic heating cartridge, a thermistor equipped with very convenient and handy set for connection without soldering, 30x30mm cooler, set of mounting screws, lock ring for fluoroplastic tube and hexagonal key.
In our opinion, all the materials for the hotend were chosen really wisely: the heatbreak with walls made from stainless steel and thickness less than one millimeter. Stainless steel is very durable metal with minimum thermal conductivity, which results in reduced heat loss, i.e. amounts of heat transmitted to the heatsink are really low. The heatsink itself is made from aluminum, which is light metal with perfect thermal conductivity. It was used to effectively remove heat from the upper part of heatbreak. Brass nozzle – is the best choice between thermal conductivity and solidness.
To create high-quality hotend, the manufacturer needs to provide minimum temperature gradient in the channel which is used for plastic intake, because it allows to avoid creation of so-called “jams”. I will give an anti-example to make it totally clear: let’s imagine that we are using a nozzle with low-quality heatbreak, and temperature gradient is long and smooth, giving us 240°C at the nozzle tip, making plastic almost liquid, because such state is necessary to go through small channel of the nozzle. When we move higher to the heatbreak, temperature is slowly going down to 200 – 180 – 150°C… giving us 80°C at the most upper part of hotend. When the plastic goes through such channel it starts to melt not at the tip of the nozzle, but even long before. ABS Plastic starts to melt at 100°C, getting gel state at 180°C, thus making a “jam”. In such state of plastic pressure, that usually goes from the top to the bottom, changes its direction and starts to move extensively, like in liquid. In that case the extruder needs more power and force to push the plastic wire down, “jam” size increases resulting in too strong resistance and occlusion of the hotend. In fact, such melted plastic in the hotend channel is called “jam”.
That’s how temperature gradient of the E3D-v6 heatbreak looks like:
As you can see on the image above, gradient is really short and nothing will melt in the coolest part of the heatbreak, thus you can forget about “jams” problem. This feature allows to use fluoroplastic tube effectively and durably. That tube is connected to the cool part of the heatbreak, providing perfect sliding of plastic from toothed wheel of the extruder down to the heatbreak itself almost without backlash, making printing with rubber-like materials much more easier. Because if the fluoroplastic has no direct contact with hot parts of heatbreak, there’s no any chance of its deformation or damage by heat!
You can find many fake copies of metal hotends from China on Aliexpress or eBay websites, but mostly all of them have one technical disadvantage – fluoroplastic tube goes through heatbreak and has direct contact with hot parts of the hotend, resulting in guaranteed deformation of the tube after a while and hotend occlusion. We highly recommend you to purchase only original hotends directly from manufacturers, which will save your money, time and even nervous cell in some cases!
It’s really convenient when the hotend is equipped with quick release nozzle, and the E3D-v6 is one of such hotends. You can easy feel such necessity when the nozzle is clogged with waste and you have to clean it or just in case when you need to use nozzles with different diameters to print using plastic with wooden structure that includes large particles. Nozzle tip is not sharp and can easily smooth out printed layers. All the nozzles are marked with convenient size marking, when quantity of marks on the edges of the nut shows us the size. There are several available sizes on the manufacturer’s website: 0.25mm, 0.3mm, 0.35mm, 0.4mm, 0.6mm and 0.8mm.
Mechanical assembly of the E3D-v6 hotend takes around two minutes, adding two more minutes for thermistor connection. Here’s short assembly instruction:
- Screw (with hands) the nozzle into the heater block against the stop from the side, where the hole for heating cartridge is closer, unscrewing it by a half-turn;
- Screw (with hands) the heatbreak into the heatsink against the stop;
- Screw (with hands) the heatbreak with the heatsink into the heater block against the stop;
- Tighten the nozzle using a wrench and holding the heatsink with your hand;
- Insert heating cartridge into the heater block and drive long screw using hexagonal key from the package fixing the cartridge;
- Cover thermistor legs with blue insulation from the package, cutting it in advance such way that thermistor legs are out by approximately 1 cm;
- Put metal connectors over the insulation on thermistor legs;
- Twist thermistor legs with wires which connect to electronic circuit board of 3D-printer and compress metal connectors in the place of twisting;
- Insulate connections. Everything is ready now!
The hotend uses standard “Groove mount” system, with external diameter equal to 16mm and diameter near the groove equal to 12mm. You can find many ready-made mounts in free 3d-model catalogues by searching “e3d mount” or “groove mount”, thus you’re not going to face any difficulties.
The manufactures claims that maximum working temperature of E3D-v6 hotend can go up to 400°С (when there’s a sensor, capable to measure such temperature). Hotend is shipped with Semitec 104GT2 thermistor, which has working temperatures range from -50°С up to +300°С, making it possible to print using any type of high-temperature filaments, e.g. nylon (260°С – 280°С) or polycarbonate (260°С – 290°С).
The hotend heats really fast, getting up from 21°С to 250°С in just 80 seconds. Such high speed is reached by the principle of connection of heating cartridge to the aluminum part. Really often cartridge is fixed with screw, resulting in small contact area with heater block. In the E3D-v6 cartridge is fixed by the heater block from all sides, therefore heat transfers to the block much more better. Printing with the E3D-v6 is very accurate, and there are no leaks of the plastic from the nozzle!
By the time of writing this, our E3D-v6 processed more than 2 kilograms of plastic without even one problem, and we have nothing to complain about, because printing is really stable. This is unequivocally the must-have!