LumenPnP linear rail mods (V3)

prusaprinters

NOTE: This is for the V3 LumenPnP. If you're currently using V2, you'll just need to print a few additional parts which are listed below.This mod provides a minimalist set of parts for upgrading the LumenPnP X & Y axes from v-slot rollers to linear rails.The design intent here is to make as few changes as possible to the original LumenPnP design. As such, this preserves the overall dimensions and travel of the machine, as well as maintaining the existing Z-height.Non-3d printed parts required:2x 550mm MGN12H rails1x 500mm MGN12H rails24x M3 drop in T-nuts (like these or these) for mounting the rails24x M3x8mm bolts for the T-nuts12x M3x10mm bolts for the rail carriages4x M5x10mm bolts for securing the X-axis extrusion¹12x M5x12mm bolts for the belt clamps¹8x M5x12mm bolts for mounting the front and back of the X-gantry4x M5x20mm bolts for mounting the X-axis to the Y-axis4x M5 drop in T-nuts for securing the X-axis extrusion¹26x M5 hex nuts¹: these should have been in your kit.3d printed parts required:2x x-gantry-block-mount2x y-gantry1x x-gantry-back2x MGN12 alignment blockIf you're upgrading from the V2, you'll also need these 3d printed parts from the V3 release:1x x-idler-mount1x x-motor-mount1x x-motor-cable-guide1x z-gantry-left1x z-gantry-rightDisassembly:Remove your X axis from your Y axis.Remove your x-motor-mount and x-idler-mount from your X axis. You'll re-use these parts.Remove the belt clamps from your x-gantry-back. You'll re-use these parts.Remove your x-gantry-front. Leave all the stuff mounted to it in place. You'll re-use this subassembly.Remove the top-camera-mount from x-gantry-back. You'll re-use this subassembly. Keep the bolts and nuts with it.Remove the remaining X gantry parts - the x-gantry-back along with the spacers, wheels, x-gantry-roller-carriage. At this point, your X-axis 2020 extrusion should be bare. You won't need any of these parts.Remove the belt clamps from both of your y-gantries. You'll re-use these parts.Remove the entirety of your y-gantries, including the wheels, spacers, and supports. At this point, both of your Y-axis 2020 extrusions should be bare. You won't need any of these parts.Assembling the Y-axis:Using the MGN12 alignment blocks, M3x8mm bolts, and T-nuts, attach the 550mm rails to the top of the Y axis extrusions. Place 8 bolts and T-nuts for each rail.Insert 5x M5 nuts into the backside of each of the new y-gantries. If you're having trouble keeping them in while assembling the machine, you can hold them in place with short M5 bolts.Re-attach the Y axis belts to each of the new y-gantries using the belt clamps and 8x M5x12mm bolts. The belt is routed exactly the same as the stock LumenPnP. You don't have to have the belts perfect right now, just make sure they're attached.Use the M3x10mm bolts to attach each y-gantry to the linear rail's carriage. Take care to make sure the belt routes through the y-gantry properly and doesn't get twisted or tangled.With the y-gantries secured to the rails, check to make sure you'll be able give the belts adequate tension by tugging on the tensioners. If it's too loose, loosen one of the belt clamps and pull the belt taught while re-attaching the clamp.Mounting the X-axis:On the right side of the machine, attach the x-idler-mount that you previously removed to the y-gantry using two M5x25mm bolts. These bolts should attach to the nuts you placed on the back of the y-gantry.Insert the X axis 2020 extrusion into the x-idler-mount. Don't bolt it down right now.On the left side of the machine, push the x-motor-mount that you previously removed over the other end of the 2020 extrusion.Use two M5x25mm bolts to attach the x-motor-mount to the y-gantry.Move the X-axis all the way to the front of the machine. It should move easily on the linear rails.Use four M5 T-nuts and M5x10mm bolts to secure the X-axis 2020 extrusion to the x-idler-mount and x-motor-mount. You can drop the T-nuts in the extrusion just outside of the mounts and push them in place using a small hex wrench.Double check the X-axis movement. If it feels like it's running into more resistance at one end of the machine, your machine may not be square.Assembling the X-gantry:Use the alignment blocks along with 8x M3x8mm bolts and T-nuts to attach the 500mm rail to the top of the X axis extrusion.Attach one of the x-gantry-block-mounts to the rail carriage using four M3x10mm bolts, with the flat side up.Insert four M5 nuts and two M3 nuts into the back of the x-gantry-back.Re-attach the X axis belt to the x-gantry-back using four M5x12mm bolts. Just as with the Y axis, the belt is routed exactly the same way as the stock machine. Once again, you don't need to get the belt perfect, just get it attached.Place four M5 nuts into the slots on the top of the x-gantry-block-mount.Attach the x-gantry-back to the x-gantry-block-mount using two M5x12 bolts. Screw the bolt through the x-gantry-back and into the captive nuts. Do not use longer bolts as they will collide with the linear rail.Check to make sure you'll be able give the belt adequate tension by tugging on the tensioners If it's too loose, loosen one of the belt clamps and pull the belt taught while re-attaching the clamp.Place four M5 nuts into the slots on the top of the second x-gantry-block-mount.Attach the second x-gantry-block-mount to the x-gantry-back using the two bolt holes underneath the 2020 extrusion with two M5x12mm bolts.Attach the x-gantry-front to the two x-gantry-block-mounts using four M5x12 bolts.Attach the top camera assembly to the x-gantry-back.Double check the movement of all axes and re-tension the belts.Reconnect all of the electronics and pneumatics.After completing the build steps, you need to update your calibration in OpenPNP. While this mod attempts to keep the Z-height the same, it is likely to be just different enough to cause trouble.Jog the head over to the datum board and re-focus the top camera.Re-calibrate your top camera's mm/pixel.Re-calibrate the Z-height for the primary (and secondary, if applicable) fiducials.Update the Z-height on all feeders, tool changer locations, and board locations. If you don't, you risk the head crashing into things.