hello I would like to build a slab flattening sled similar to the one in the photo but would Like to build it from extruded aluminum C track. I will move it manually but I would like to have two long side rails and a gantry rail. I would mount a router on the gantry so basically just like a CNC machine but I would like feet That will screw down to a work surface and a way to manually set the Z height and keep it locked. My issue is I have never worked with any of this material and I do not know the components I need. I have been trying to figure it out and have a sense that I need rails and a way to attach the gantry so that it will move. A gantry plate and a way to attach my router to it as well as some kind of feet to attach it to a work table. I would so appreciate any help in building a Parts list for the Open Build parts store. Thanks so much!