We’ve been doing some really cool research into toolhead switching options in the big-thompson research project (http://devel.lulzbot.com/research_projects/big-thompson/video_and_photo/). The concept is that a printer could have a rack of toolheads (different colors, flexy’s, MOARstruders, etc) and could actively set down and pick up different toolheads during the print similar to CNC tool changing.
We considered using an electromagnet to pick up the toolheads, but this would become an issue if power failed and you dropped your fancy toolhead. Instead, we’ve been playing with the ultra cool OpenGrab board (https://github.com/Zubax/opengrab_epm_v3). It’s an electro-permanent magnet that can be “switched” on or off, and requires no power input to maintain a surprisingly strong holding force.
We’ve got a quick and dirty prototype set up that combines the opengrab with a maxwell style kinematic coupling that should make the pickup sequence super repeatable. The holding force is more than enough to tightly secure our heaviest toolhead (the dual extruder) well enough for reasonably fast printing.
Pretty stoked about this