Hot End

thingiverse

My last hot end. Temperatures were taken with a thermocouple in direct contact with the inside of the nozzle. The temperature measured at the end of the threaded M6 rod, stabilises at 46°C above the room temperature when the hot end is kept at 250°C. I had to set the temperature at 273°C in order to reach 250°C. But I used the distribution table for the thermistor. Instructions The heating bloc is traced at 4, 6, 6, 4mm. Thermistor and resistors were glued with thermally conductive silicone adhesive. Resistors AS-2 http://www.irctt.com/file.aspx?product_id=481&file_type=datasheet Thermistor B57560G0104       http://datasheet.octopart.com/B57560G104F-EPCOS-datasheet-16188.pdf MACOR http://www.technicalproductsinc.com/pdf/macor.pdf Insulation tape T-FG-SG-M051-32-X       http://www.firesleeveandtape.com/AB-Thermal-catalog-T-FG-BM.pdf Thermally conductive EP36AN http://www.masterbond.com/sg/masterbond_tcsg.pdf Insulation tape was glued with Hardex 650°F red silicone. Remove carefully the isolation where the mozzle fits. I used a 10mm punch with the nozzle in place. The connection between the two resistors must be crimped the others connections can be soldered. UPDATE: It's not working as expected! a) When you extrude at full speed the heat transfert is not fast enough. b) PLA get clogged inside of the stainless steel thread if the temperature is set higher than 200°C. So, I redesigned it. 1) I kept the resistor bloc that works great. 2) The nozzle has now a M6 tail of 20mm. His head size is 10mm and drilled at 0.4mm. 3) The thermal barrier is machined in MACOR and has 35mm long. 4) To avoid clogging a teflon tube of 3.4/3.8 is inserted inside the thermal barrier and the threaded part of the nozzle. I will post a new drawing as soon as possible.