3D printed bearings experiments

grabcad

all of those aren't working as intendedbut some are cooland easier to understand than real bearings (so might have some educational value)helical (37 marbles) : the nut is able to fall down from it's weight, same for the screw (see the video) but the marbles aren't circulating, it's just that the screw doesn't grip to the marbles, so it is able to move nonthelessit is too much imprecise to be usefull for anythingit might be because the turning radius of the canals are too little for this size of marble, and it could use some grease, and anyway i think it isn't possible to get something hard and smooth enough to do a usefull bearing out of a FDM 3D printerlinear (33/36 marbles): in this one the marble circulate if you put enough force on the shaft going insidebut for the same reasons as above, not precise enough of a guiding (http://orig13.deviantart.net/3c39/f/2016/103/d/c/linear1_by_nagby-d9ysgh6.webm) and not smooth enough (http://orig03.deviantart.net/c57d/f/2016/103/8/0/linear2_by_nagby-d9ysgf6.webm)standing spool bearings : after the flat bearing i made, i wanted to try other things with the spool standing uprails take a part of the outer diameter of the spool with lot of marbles (108)radials takes only 4 points of the outer diamter, with less marbles (56)but in both, the marble circulate hardly and tries to escape http://orig08.deviantart.net/a4d2/f/2016/103/6/a/curve1_by_nagby-d9ysgdr.webmhttp://orig11.deviantart.net/d05c/f/2016/103/f/6/circle1_by_nagby-d9ysgck.webm