Lately, I have been asked if I will be making more J-Head Mk 8 hot-ends. In addition, I have developed a proper J-Head bowden hot-end that is based off of the J-Head Mk 8 and have named it the J-Head Mk 9.
However, I will not be producing nor selling more of the J-Head Mk 8's and Mk 9's because of what has happened to the J-Head hot-end.
The chinese made a poor, rough, copy of a J-Head and spammed it all over the online markets. People bought the cheap knock-offs and those hot-ends failed. The result was that all J-Head hot-ends got blamed for this failure even though the cheap chinese knock-offs were (and are) very different from the real J-Head hot-end. Most of these people now buy other hot-end designs.
The closest open-source analogy that I can think of is this example: Imagine if somebody took FreeBSD, introduced a couple hundred bugs, then released it as a new Linux distribution. Because of this, people begin to dislike Linux. In my opinion, this is what happened to the J-Head hot-ends. (Please note that this is not meant to say anything negative about FreeBSD, it is just an example.)
The concept of open-source design is to take a product and improve it then release the source code or blueprints. It is not to take a product, break it, then not release any information.
Because of this, I have stopped all research and development work towards better J-Head hot-ends. I absolutely refuse to create new designs given what has already happened. I have also noticed that a lot of Reprap-related R&D has stopped in other areas as well. This makes me wonder if the other developers have left due to similar reasons.
I would also like to add that you get what you pay for. Quality products and new research and development cost money and a company that sells both will have to charge a higher price. A cheap, poorly made, knock-off will be cheap in both price and in quality.
I am still selling the J-Head Mk V-BV hot-ends at http://www.hotends.com.