I've been working on a FLA-100 build and was dealing with the hassle of trying to align the z-axis rail assembly when inspiration struck. I thought I'd share it in case anyone else is interested.
It's effectively a third hand with adjustment screws to raise, lower or tilt the z-axis assembly. The wood piece is 1.5" square by 14" long oak scrap. It's affixed to the 80/20 extrusion with 5/16-18 hex bolts and a couple of 80/20 t-nuts. The outer adjustment screws are 1/4-20 hex bolts about 3 or 4 inches long. There are regular t-nuts hammered into the bottom of the oak for the 1/4" bolts to push against. I filed the grade markings off of the heads of the 1/4" bolts so they would turn smoothly against the y-axis rail. Once the oak piece is bolted to the back of the extrusion, the whole assembly can be easily and quite finely adjusted by turning the 1/4" bolts. Once aligned, it held its position even while tightening the bolts on the linear carriages.
Sorry I don't have a CAD drawing, I was just kinda winging it when I put it together. The only measurements of importance are the extrusion mounting holes, which are centered 1.5" apart, and the alignment of the adjustment screws over the y-axis rail. In the side view, the adjustment screw holes are centered 1-1/8" from the left face of the oak board.
It's effectively a third hand with adjustment screws to raise, lower or tilt the z-axis assembly. The wood piece is 1.5" square by 14" long oak scrap. It's affixed to the 80/20 extrusion with 5/16-18 hex bolts and a couple of 80/20 t-nuts. The outer adjustment screws are 1/4-20 hex bolts about 3 or 4 inches long. There are regular t-nuts hammered into the bottom of the oak for the 1/4" bolts to push against. I filed the grade markings off of the heads of the 1/4" bolts so they would turn smoothly against the y-axis rail. Once the oak piece is bolted to the back of the extrusion, the whole assembly can be easily and quite finely adjusted by turning the 1/4" bolts. Once aligned, it held its position even while tightening the bolts on the linear carriages.
Sorry I don't have a CAD drawing, I was just kinda winging it when I put it together. The only measurements of importance are the extrusion mounting holes, which are centered 1.5" apart, and the alignment of the adjustment screws over the y-axis rail. In the side view, the adjustment screw holes are centered 1-1/8" from the left face of the oak board.