Monday, March 12, 2012

Goals for the J-Head Mk V

While I am always looking for ways to improve the J-Head Hot End, I am finally listing the goals and design changes planned for the J-Head Mk V.

  • Shorter Overall Length
    • A shorter nozzle holder and nozzle have been designed.  The overall length will be about 13mm shorter than the J-Head Mk IV-B.
  • Lower Extrusion Pressure and Faster Extrusion Speed
    • These two go together as increasing the length of the melt chamber will do both.
  • Designed For the 6.8 ohm Resistor
    • While the 5.6 ohm resistor works great, it is hard to find and the 6.8 ohm resistor is more common. 
  • Nozzle May Use 1/2" x 1/2" Brass Stock.
    • This will make the nozzle footprint slightly smaller.  In addition, it will make the use of aluminum much more feasible as 2024 is readily available in this stock size.
  • Different Thermistor Mounting Location.
    • The thermistor mounting location will most likely change due to space considerations in the nozzle.
    • It may be a good idea to put the thermistor closer to the resistor and PEEK in order to reduce the possibility of reaching a temperature that results in the PEEK nozzle holder melting when the temperature is set near 248 degrees C.


  1. Hello,

    No plans yet as the design is a combination of some others and what may be the final design hasn't been built yet.

    After the Mk V is tested, I'll release the plans for it.



  2. I did myself your hotend mk4b and modified PEEK holder narrowing upper hole to prevent PTFE tube from moving up from the holder. Now precious length cutting of teflon tube required. But it works good.
    The idea is from new SeeMeCNC holder design. There was such a problem in SeeMeCNC older design (I am an owner of this printer).

  3. From version 1 to 4 you increased melting volume (and making teflon tube shorter and shorter). Why? Does it really affect quality of printing?

  4. Hello,

    I increased the melt zone so as to decrease the pressure required for extrusion.