From a guy that has actually put over 100 cord through a splitter with auto-cycle.
In terms of safety, all the crap and horse manure about them being dangerous is complete and total BS nonsense spread by idiots and jerks that have never even used a splitter with auto-cycle.
I’ve never had anything but full auto-cycle, I’ve put probably 500 cord through mine… and there is some danger not readily apparent. My valve isn’t like any you can buy and install; a single spool with a single robust lever you could sit on and never damage, has no “adjustment” screws, is welded to the splitter and the steel hydraulic lines are welded to it. The valve also controls the engine throttle… I toss a round on the beam and slap the lever, engine speeds up, ram extends, retracts, lever returns to neutral and the engine idles down.
Now here’s where the danger is… I’ve had it happen three times over the years. After slapping the lever I usually turn to grab another round, so my eyes are off the splitter, and my feet. The wedge is on the end of the beam so most splits slide off the end out of my way. Occasionally a round will “pop” almost as soon as the wedge touches it and send the split to the side. Well, I’ve turned with the next round and tripped over this split (or something else), falling and landing with some part of my body on the beam (hand, arm, shoulder, whatever) between the wedge and still extending ram. I’ve always been “aware” enough to get off the beam fast, even if it meant taking more of a “hit” from the fall. But…
Now I suppose someone could say that having a second person operating the valve would eliminate this danger… but that would defeat the whole purpose of a fully auto-cycle valve don’t you think? When I have a helper they’re standing off the end of the beam, behind the wedge catching the splits as they come off… at the opposite end from the lever.