Here is a dual E3D hotend effector setup for use with magnetic arms on a Rostock Max. I've been running with this setup for several months now There is also a top piece [shown in yellow] to adapt a non-bowden E3D for use with a bowden tube on delta type printers. Download the attached ZIP file with the STLs in it. I recommend you print these parts at a very small layer height to make sure they come out dimensionally accurate.
Cool - enjoy the magnetic links should imagine that makes for nice and easy assembly / disassembly. I am currently in the process of rebuilding a very large delta-bot and need to decide on some new linkages, may give these a go. I have updated the max upload size to 20MB which should be sufficient, if not then it may be best to just host on thingiverse.
Nice design! Try compressing the STL file.. usually the compressed file has less than 50% of the original size.
Thanks for posting this! I can put this to good use, once I get my magnetic arms made. So much to do with so little time!