A few months ago, we were asked if we would like to try some J-head-hotends.
The currently available arcol.hu hotends work just fine, but you just can't have enough hot-end options. So we googled j-head-hotends and found a nice description about it on the reprap/wiki.
The design seems to be pretty simple, and since there are some supply difficulties with the arcol.hu hotends we decided to give the J-head-hotend a try and ordered. As they arrived, we were pretty happy because they are pre-assembled, take a look at this picture.
After finsishing the assembly of a hotend with a standard 0.5 mm orifice (the thermistor and the heating resistor have to mounted by the user), we tested how it works using translucent blue PLA:
The temperature was a little too hot in the first try because we didn't adjust the thermistor table, but the melting zone seems to be very short. About 1 cm, not more.
So we went on testing printing with and without fan and measured the temperature after some hours of printing around the extruder and at the PEEK heater-barrel.
With fan the PEEK is around 50°C and the inside of the extruder about 35°C, while the nozzle has around 190°C. Without fan the inside of the extruder reaches up to 55°C - but obviously not too hot to print PLA.
The first test-prints were just fine. Nothing went wrong, no blocking of the nozzle, no mess :-)
The next step was to try ABS. Therefore I first had to add a heated printbed to my prusa 3D printer because I never printed ABS with this machine The result was looking great, look at the following picture with the printer in action.
The J-head hotend was also able to nicely print ABS. The temperatures without fan were around 90°C on the PEEK and about 65 °C inside the extruder.
And it also successfully completed the longterm test printing a ABS Wades extruder:
If you like to buy a j-head-hotend, we have some in stock in different orifice sizes on www.2Printbeta.de.