The end of the Dragon Hotend?

Is this the end? Let's try to unravel the mystery.

What is the Dragon hot-end?

The Dragon hot-end is a hot-end that was originally introduced by the Chinese company Phaetus. It combines elements from the E3D V6 with elements of the Mosquito by Slice Engendering. They have copied the design of the heartbreak and the way that the heat block is mounted to the heat sink. The E3D V6 uses the heat-break also as the mechanical mount between the heat block and heat sink. Unlike the V6 design the Mosquito uses small stainless steel pipes with small screws to heat block tot he heat sink, that allows to have a very thin metal tube with cooling fins as heat break. This part was obviously copied by the Dragon hot-end.

Mosquito by Slice Engineering

On the other side the Dragon kept the exact out dimensions of the E3D V6, including the mount ring which is optional on the Dragon(at least the TL versions I have). So in contrast to the Mosquito with its very distinct shapes that usually requires a different mount and even a different Extruder body (on the Prusa Mk3 for example), the Dragon is a drop-in hot-end that does not require any changes.

clone of the E3D V6

Not only the mount, also the heat block and the mounting for the heater cartridge and the thermistor are the same on the Dragon and the E3D V6.

Triangle Labs Dragon without mount ring

Slice Engineering has a number of patents on their products that can be found here, some are still pending.  https://www.sliceengineering.com/pages/ip

Now it seems like Triangle Labs fears that SE could sue them for patent infringement and being forced to pay royalties. This is why they have now stopped selling the Dragon hot-end.

If Phaetus will also stop selling the Dragon hot-end is not clear yet. But definitely bad news for all users of the TL Dragon as they might not get any spare parts in the future. 

According to Mr. Warkocki, the admin of the Prusa community group on facebook, SE has denied that they actually threatened Triangle Labs. But that does not mean that could go down that road in the future and Tl just proactively stopped selling it to avoid problems in the future.

Other sellers hoped up on AliExpress now, selling Dragon hot-ends for less than $20. If they are even close tot he quality of the TL Dragon hot-end, I don't know.

If there is enough substance for an infringement claim would be up to a court to rule on. Or if the SE design is that ground breaking different from the V6 that is justifies being protected by a patent could also be subject for discussion.

To me the fact that 3D printing was already invented in the early 1980s(FDM 1989), then protected by patents until the early 2000s held by companies like Stratasys until it became available for hobbyist because of the reprap project in 2008, is a point against patents. Especially as it seems we are now going back from open/free technology, back into the world of patents and closed development.

I guess Prusa is a good example that you can have development and make money while you open source your products, if you have a good product for a reasonable price and offer a good service.