That helps extruder precision, there’s less wiggle room for the filament to “coil up” or just compress and act as a spring, which compared to an average extruder lets you lower retractions slightly, gives more accurate extrusion, but also lowers friction, which you really need for flexibles. That makes it super compact as a unit, but also shortens the filament path between the extruder gears and the nozzle by quite a bit.
The front plate of the extruder is also the heatsink for the hotend and the stepper motor’s covers do double duty as the backplate of the extruder and as mounting points. But the nice thing is, instead of having an extruder body that you use with a hotend and a stepper motor, it’s all combined into one group of parts. In fact, you can only buy it with the v6 hotside or as a Bowden version, which is just taking out the hotside and Hemera-specific heatbreak and replacing it with a Bowden adapter, aka the Bowdapter, and you obviously don’t need the fan anymore. Okay, the biggest and most obvious new thing with Hemera is that it really is intended to be used in combination with the included v6 hotside. So let’s check out what’s new and what’s different compared to what else is out there. It’s a hotend – extruder combo that I think does pretty much everything right. So this is the hot new product in 3D printing right now – it’s the E3D Herm.