This design is based on Adrians design from HERE
I found a weakness in the this and other similar designes. The PTFE heat Shield fails where it screws into the nozzle.
My design gets around this issue by using the PEEK block to support the PTFE heat shield.
The PTFE is made with an additional 10.5 mm shoulder
The PEEK Support block is drilled 8mm to hold the nozzle then 6mm deep at 10.5mm
I found that the 10mm thick heater blocks made the melt zone a little too long.
I make my heater blocks ~8 mm thick and have shortened the nozzle length by ~2mm.
The result is a strong and durable Hot End based on a very well tested and proven design.
The Thermistors I use are ATC Semitec. Part Number 104GT-2
The Resistors I use are from the TrueOhm KNP range. Part number KNP-300S 6.8R
The Wire I use is from Alphawire. Part number 5858
Heater Block: Insulate the resistor wires. I use kapton tape. Coat the resistor in Car Exhaust assembly putty and insert into the 5mm hole. Strip 20mm of insulation from the PTFE Wire and thread over the Thermistor wires. Coat the Thermistor in the Exhaust putty and insert into the small thermistor hole. Leave the Heater to Dry for a few hours and use the Crimps to attach the wires.
Nozzle: Push the nozzle through the 8mm hole in the PEEK Block. It's supposed to be a tight fit. Run a fingernail around the shoulder of the PTFE then carefully screw it into the PEEK Block. The PTFE shoulder will be a snug fit in the PEEK. You can then screw the heater Block onto the nozzle.