This one was made by myself, my very first 'home made' hotend for my Prusa Air 2 3D printer, 0.4 mm nozzle, 2 x 6r8 resistors, 3mm filament. Made of brass and ptfe.
|Pic.1 just another reprap hotend...|
The one from Pic.1 was based on my first hotend I got on ebay, which started to leak ABS after few days of printing (Pic. 2). Yeap, this black 'thing' is a melted ABS.. My version worked quite well but I didn't have time to fully test it.
I can only say that PTFE is not great for higher temperatures, probably it would last longer if used with PLA:175-180 degrees but it gets too soft at 230..
|Pic.2 Leaking PTFE hotend|