Tired of getting a 10 hour print and your extruder ruined by a spool getting tangled? even attended prints can get ruined in 30 seconds since you don't always notice the tangle before the filament stops flowing resulting in an air print.
The anti tangle system (ATS) is a set of printable parts that put your rep2 into cold pause whenever there is a tangle.
see it in action: youtube.com/watch?v=DEAy2hf6FU0
print the parts, add a piece of cord (fishing line works well). the ATS works by moving a lever that presses the hardware pause button if a tangle happens. you can then solve the tangle or change filament, unpause the machine, and enjoy a saved print.
Update : you can use jettyfirmware.yolasite.com/v74-v44.php#pstop the new sailfish to add a p_stop switch and use only the back assembly. however for the rep2 the jetty team hasn't figured out the P-stop yet. so we're waiting for that.