Heater Block with Screw-On Thermistor

This Heater Block is an advanced version of previously published heater block to be used on Makergear hot ends or DIY designs.

Advancements are:
1. Use of M3 stud screw-on thermistor. It is easy to install and remove, makes assembly and maintanance of hot end really simple.
2. Another useful feature is ability of heater block assembly to be secured on barrel with M3 x 6 set screw. This will prevent block from twist during nozzle changes. This feature is similar to one found in updated bu