kossel self-locking carriage for reticulating mounts

I loved the 3/16" steel recirculating bearings design, but didn't like the original carriage mounts, the belts would slip and the original square grips broke off. I loved this self-locking carriage idea more so than the split groove design, so I blended the mounting bracket portion from mkeveney with carriage from wuz23 and there you have a new and very effective replacement. works extremely well on my rig now for almost a month, so I can claim it's good and clean. it is a little tight horizonta