I’m slowly building a rather different printer on top of the skeleton of my Tronxy X5S. Previously I replaced the Z mechanism with a single motor and continuous belt driving synchronized single-start 2mm lead threaded rod, and milled alignment jigs to mount linear rail to the top of the Y axis and front of the X axis extrusion. Today I finished milling a set of gantry mounting plates out of 1/4" (6.35mm) aluminum plate to attach the X gantry extrusion to the Y linear trucks.
My prototypes last week were a little sloppy and tended to bind. While milling these new mounting plates, I worked to or even beyond the 0.01mm precision of the DROs. That long slot down the middle is for 2020 extrusion to fit into. When I had milled it 20.00mm wide according to my DROs, the 2020 was too tight a fit. I moved the bed slightly, but not enough to register on the DROs, and could hear that the mill was just barely touching as I ran it down the part, making the slot less than 0.01mm wider—but making the slot a perfect fit for the 2020 extrusion; a snug but easy fit, with no wobble.
Unlike my prototypes, I put the center drills in collets to start the holes, and now they are sufficiently precise that the whole mechanism stays very square. It no longer binds while moving in Y as the prototypes did.
The smaller holes are 3mm holes for M3 machine screws to go through into T-nuts (extrusion) or threaded mounting holes (Y linear trucks). The larger holes are threaded M5 into which to screw M5 bolts with 635ZZ bearings (for the back side of the belt) and 20 tooth idler gt2 belt pulleys (for the front side of the belt). They are aligned to attach to the back of a plate screwed to the X linear truck. I plan to lock them in place with an M5 nut on top of the plate, and hold the idlers at the right height with 5mm ID bushings.
The aluminum is from scrapyard special 100mm x 100mm x 1/4" plate. “Reuse” comes before “Recycle” remember!