I’m working on something pretty awesome that I think you guys will get a kick out of. As you may know, we’re hard at work on a new printer codenamed Azalea (http://devel.lulzbot.com/Easy_TAZ_Mini/Azalea); the goal is to produce TAZ quality parts with as little calibration and fiddling as possible.
We’re currently going down a couple of routs for the bed leveling, but my favorite by far is a force sensitive resistor (FSR) based system. It’s clean, adds no additional moving parts and will completely get rid of the probe to nozzle offset calibration that plagues other bed leveling systems. Here’s a setup pretty similar to what we’re working on: http://www.youtube.com/watch?v=HcnhCNh2Ln4
We’ve got the mechanical components pretty well nailed down, and as always the development source is openly available: http://devel.lulzbot.com/Easy_TAZ_Mini/autolev/. In order to avoid mechanical calibration of the FSR sensitivity we’re looking at using one of the extra thermistor ports to read the resistance of the FSR’s, rather than the Z endstop pin.
On the firmware side, I’m getting tripped up trying to get the firmware to recognize a drop in the readings from thermistor port 3 as a Z-home indication (nozzle touching glass=homed in z). Anyone interested in helping out with the firmware tweaks? You’ll definitely earn my eternal gratitude (and possibly some Lulzbot schwag )
More updates to come