I've been through numerous hot end designs trying to find one that I am happy to sell through Makershop and The All-metal hotend from E3D was my clear favourite. This stainless insulated actively cooled Hot-End - Contains no PEEK or PTFE anywhere near the hot zone. The all metal design will withstand temperatures well in excess of those required for thermoplastic extrusion. Extremely strong easily repairable. It is also quick and easy to change nozzle sizes (more nozzle sizes coming soon).
The following information is reproduced from the E3D website with permission.
The E3D-v6 has been redesigned from the ground up. We have invested a lot of time and used all of our experience to design E3D's latest and greatest HotEnd. If you would like to know more about the design process, check out this blog post.
Building on our signature high temperature performance that allows you to print high temperature materials we've now focussed on adding increased functionality with soft and flexible filaments. By providing a PTFE liner tube through the hotend that you can extend into your extruder this gives the ability to add the confinement and constraint needed to make excellent quality prints with flexible filaments like NinjaFlex, FlexPLA and FlexPolyester. This opens up a huge range of new opportunities for your printer.
(PTFE Liner only present in 1.75mm version - 3mm Bowden has partial lining - 3mm Direct has no lining)
This above cutaways show the internals of all three HotEnds. Left to Right: 1.75mm Universal, 3mm Direct, 3mm Bowden.
With no PEEK or PTFE in hot regions of our HotEnd we can reach 300C with the supplied thermistor. By swapping a thermistor for a thermocouple (may require additional electronics) you can reach over 400C.
This not only allows you to print extremely high temperature materials like Polycarbonate and Nylons but also eliminates HotEnd meltdown failures associated with PEEK/PTFE designs. Although our latest v6 hotend has a PTFE liner inside the hotend this liner is never subjected to high temperatures so there is no risk of damaging the liner through overheating.
Our new HeaterBlock gives the fastest heat up times and the most responsive temperature control by clamping around the cartridge for maximum thermal contact. The new thermistor placement means you get the most accurate temperature readings with the fastest response. What this means for you the user is that you can go from 20C to 200C in just 65 seconds, temperature control is responsive enough that you can keep the hotend within 0.5C of your set temperature or less with ease.
We've focussed on cutting as much bulk from the E3Dv6 as possible. This means an overall length of just 62mm and significant reductions in bulk in the X/Y dimensions by using our new injection moulded fan duct.
We've eliminated Kapton tape or any other adhesives from the assembly process of v6. The new thermistor simply clamps into place with a small screw, high temperature glass sleeving is used to insulate the thermistor legs. This makes installing or removing the thermistor a quick and clean process compared to previous methods involving fiddly kapton taping. No soldering is needed as we supply supply solder free ferrules for making heat-resistant, quick and easy electrical connections to the thermistor legs. Most parts of the hotend simply screw together, the new fan duct simply clips into place and can be oriented in many different directions to suit your particular setup.
We've kept our sharp thermal transition that gives the high quality printing performance users have come to expect from E3D hotends. A sharp thermal break gives better control over filament output so you get more immediate start and stops when extruding as well as retracts that are more effective in combatting ooze. For the user this means sharper more accurate prints that have less stringing, oozing or blobs on the prints.
Our range of nozzle sizes gives you more oppurtunity to choose how you want to print. While our default 0.4mm nozzle gives great prints with a good balance of speed, ease and resolution we are offering a range of nozzles that have special geometries that are tailored to the specific needs of how you want to print. The shape of the tip of the nozzle is key to how the hotend extrudes and flattens a track of plastic. By matching the size of the tip of our nozzles to the width of track of plastic we are able to print with increased resolution in smaller nozzle sizes and with our larger nozzles we've customised the geometry so that you can easily lay down large layers for fast strong prints. Nozzles are easily and quickly changed out because of their hexagonal shape.
We've kept our same 16mm Groovemount dimensions from v5 to ensure that as much compatibility is maintained as possible with our extensive range of community designed mounts. See here for examples: Thingiverse
We have an active user base on many printer forums, including RepRap Forums, Google+, SeeMeCNC, Solidoodle, Ultimaker and many others. We also maintain our own E3D Forum where many people share and collaborate on clever solutions for mounting on various printers. We value the community that use our product and look to support development wherever possible.
We're always there to support you in using your HotEnd - whether that means giving advice on public forums, or private email support by our contact system. We stand behind our product