Wednesday, October 19, 2011

J Head Mk IV-B Is Now Available

The J-Head Mk IV-B is now available at  As with the Mk III-B, a cooling fan will be highly recommended for printing with PLA.  Printing, with ABS, will not be a problem.

Until more information is available, the shorter version, with the 36.5mm nozzle holder will still be experimental.

A Mk IV, with an aluminum nozzle, will be made; but, will probably not be sold regularly as the available sizes of raw aluminum bar stock require additional machining in order to manufacture the J-Head nozzle.  This, of course, would increase the price.  In addition, for best results, the aluminum nozzles should be insulated.


  1. Why would aluminium need insulation any more than brass?

  2. A lot of people have been using brass nozzles without insulation. However, of the handful of test aluminum nozzles that have been sent out, it has been reported to me that the aluminum nozzle was very sensitive to any airflow.

    The original Mk-IV prototype, with the smaller aluminum nozzle and 6.8 ohm resistor, has been working without insulation. However, the operator has the cooling fan airflow directed away from the nozzle itself.

  3. My experience is that if you blow air across it then it needs good insulation, regardless of what it is made from. Even soldering irons down't work outside if there is the slightest breeze.