I just had an incident with my self-designed Delta that could have been ugly if I was not at home. Two of the rods between the carriages and effector plate failed, leaving the effector (and running hotend) flopping around by the other four rods in the part that was being printed. Since the extruder was still cranking filament into the hotend, it was building itself a nest of kindling filament!
Longer story is that my effector uses 1/2 inch (~13mm) spherical magnets attached with CA glue, and the rods have M5 SHCS bolts with cupped heads machined into the tops. This setup uses larger magnets than others, and has never had a rod break loose except during an effector crash into the build plate. One of the magnets broke free of the CA glue, and jumped across the effector plate to a neighboring magnet. This messed up the magnetic force on that rod, causing it to pop off as well. These two rods were holding up one corner of the effector plate, and everyone knows what happens with a Delta when a corner isn't supported.
Before someone says that this is a problem only with magnetic joints, there's a YouTube video and a few other reports of Traxxs joints threaded into carbon fiber rods stripping out the CF and pulling in/out of the rod freely as it prints. This cold potentially happen with Traxxs joints as well.
What other uses would a tri-axis accelerometer have on the effector plate, besides detecting a tilt to shut down the heater?????
