All steel hot end for Makerbot

This is an alternative extruder hot-end design for the makerbot, though it may work for other 3d printers as well.

The big advantage is that it does not require an insulator (usually PTFE or PEEK), which causes problems for some (or perhaps many). Instead, a stack of washers and nuts is used as a heatsink to reduce the temperature.

It worked really, really well for me, no more stalled extruders, stuck filaments, half-way prints. It heats up rapidly less than 1 minute from 25 to 220 degC),