One thing that I have never been able to explain is that in all my printing with Nylon the J-head always seems to give better print results than any other nozzle I have used to-date. I do not know if it’s linked with the level of moisture in Nylon, or how the PTFE sleeve transports the material, or the level of compression, oozing or meltzone. I have a feeling it’s a combination of all these. So for Nylon I do prefer to use a J-head MK4/5 over anything else at the moment. Do watch out for cloned or badly manufactured J-head nozzles, I have had some during the year with various issues. Some requiring a massive amount of force to extrude, due to an incorrect machined nozzle hole length and others with sealing issues, incorrect use of materials and poor cooling capability giving a lot of oozing. Another interesting read for J-head background information is Brian’s J-head and ‘clone’ overview here.
1. Best for Nylon Printing (245 Degrees C @ 30-80mm/ Sec) (1.75mm recommended) 2. Good for general PLA printing (190-220 @ 10-80mm/ sec) - Exceptional performance and print results at very low PLA temperatures down to 155 Degrees C. - needs active cooling of the PEEK 3. Do not overheat or the PEEK & PTFE can fail - Keep to under 250 Degrees, insulate the heater block. 4. ‘Industry standard’ Groove mount.
Overall opinion and general recommendations