I have been working on some new hot ends for a while, I purchased several kits from makergear of the Noophead style and have one of them installed in my makerbot right now. then wouldnt you know it but makerbot releases their mk5 extruder and completly changes the course of my expiriments. after looking at their design (i have one hot end on the way and parts for 3 more) I started working on fabbing some equivelents for my mendel.
I will probably post pictures of each test one of these days but the one that im fealing the most confidant about was pretty simple. take a section of 1/8" schedual 40 stainless pipe, turn down the end to 3/8" and thread it 3/8-24. then using one of the aluminum blocks from the makergear kits I drilled it out with a Q bit and tapped it to 3/8-24.
my first test used a single resistor but it could only get to 130C so i have fabricated a new one with two resistors. I have a fealing that im going to have to drive power to each seperatly with my current set up since its a gen2 pwm board so i doubt it can handle the current draw of both resistors in paralel. I may try just applying 12v directly to one and triggering the other with software.
I will post more later, hopefuly with pictures.