Last fall a lot of discussion over cracking black walnuts....At the start I had gathered 3-5 gal pails of shucked walnuts.I made up a mechanical cracker that would break everything else easily but black walnuts are at the least very hard to crack.Not to be beaten by enthusiasm I tried some thing that worked perfectly.I mounted a 12v.actuator on a 3/8 plate added a rocker switch for fwd and back.Welded a nut on backplate to help center the nut,the act. already had a hole in shaft.The speed of act. is slow enough no worries about crushed fingers..Had to make clear plastic cover to contain flying pieces and yippy skippy I'm cracking walnuts.A quite loud noise often comes from an extra hard nut but never once did one fail to break.Prior I drove over nuts with shucks with 4 wheeler that has lugged tires that reduced volume a great deal.Then put 5 gal.at a time plus 5 gals of water in old cement mixer and let them churn for about an hour.They came out quite clean but rinsed them afterwards and found out the floaties are no good...Let them dry for 2 mos or so spread out as much as possible.(They need air to dry and they won't in the bottom of a bucket).I started with 15 gals. of dried nuts and ended with about 7 lbs of nutmeats.Probably won't do it again...The act. rating ..6000n push mode,4000n pull mode mode stroke 6" 12 volt.If you're sincere about cracking black walnuts and have nothing better to do this winter..here ya' go..Can't imagine doing it old way with hammer,wow!!