Here is a bearing that uses truncated elliptical rollers instead of balls. This is intended to be easy to print all as one print without having to try to break the bearings free. Theoretically it should just come off of the build platform working with no cleanup. This is the first thing I have made in openscad, as I just started learning it today in preparation for my printer’s arrival. Also I don't have my printer yet so don't know if it prints properly. Please try it out and let me know!Update 1.1 (FIX): Still truncated elliptical rollers. Scaling fix so that roller ends are at same z level as ring edges (they were slightly off in the original version due to a 0.95 z scaling factor that I missed). I'm not sure if it is enough of a difference to mess up printing but I figured I'd fix it anyway. Also width changed to 21mm for closer roller packing. Update 2.0: New roller profile! Now has a tiered or crowned roller profile to prevent x and y rotation of rollers. I realized that there was a possibility of unintentional x or y rotation with the truncated elliptical rollers from version 1.Update 2.1: Slightly larger rollers to reduce play and also much tighter roller packing. Same profile as 2.0Update 1.1 (FIX): Still truncated elliptical rollers. Scaling fix so that roller ends are at same z level as ring edges (they were slightly off in the original version due to a 0.95 z scaling factor that I missed). I'm not sure if it is enough of a difference to mess up printing but I figured I'd fix it anyway. Also width changed to 21mm for closer roller packing. Update 2.0: New roller profile! Now has a tiered or crowned roller profile to prevent x and y rotation of rollers. I realized that there was a possibility of unintentional x or y rotation with the truncated elliptical rollers from version 1.Update 2.1: Slightly larger rollers to reduce play and also much tighter roller packing. Same profile as 2.0I tried to design is so it would just print all at once and come off the platform working without cleanup. The things that may be problematic are: rollers breaking free from platform during print, too small of a gap between rollers and inner and outer ring, you may need to reposition the print so that it is not partially below the build platform (there are negative z values in the model, I don't know if this is a problem), inner ring or rollers falling out, the geometry may be too dense as well (as I don’t know what kind of resolution is required to get good prints), there's probably something I don't know about yet. Dimensions: Outer radius: 50mm (total 100mm across) Inner radius: 25mm (total 50mm across) Thickness: 20mm (21mm for V1.1)I've attached my openscad file as well so you guys can use it or change it or fix my mistakes. I was trying to make it somewhat parametric but couldn't get the roller number to scale appropriately. The two driving dimensions are the outer radius for the two rings and the thickness for the roller size. The number of rollers will have to be changed manually (in the last statement) if the outer radius to thickness ratio changes.I also added a sketchup file so you can easily see the shape and design of the rollers / channel.