• The Bed

    janusprotocol • 06/28/2025 at 01:19 • 0 comments

    I decided to forgo the typical aluminum extrusion bed for the CNC because I had something just as flat: wood! The previous owners of my home included a woodworker, and my engineering bay was his old woodshop. I happened to have some scrap boards that were absolutely fine lying around, so I decided to use some of that as the combo bed and spoilboard (spoilbed? spoilbed). To attach it to the Ender, I designed a bracket to couple the spoilbed to the metal platform containing the belt holder. The bracket also had counterdrilled holes designed so that four M4 X 40 mm bolts could be run through into the corresponding holes in the platform. I reused the metal springs from the headed bed, but I printed new bed levelers out of red ABS. For the bracket I used ABS-GF with three walls and 40% gyroid infill. As it didn't need to be super strong, just hold together, I designed a bitchin' hexagon pattern into it that you only get to see when you're swapping out the spoilbed. Oh well.

  • The Setup

    janusprotocol • 06/15/2025 at 01:51 • 0 comments

    I recently acquired a couple of Crealty Ender 3 v2 printers from a university salvage auction. I restored one to functionality, but I don't need two bedslingers around (and I'm very happy with my QIDI Plus4). So, I'm going to hack it into a CNC mill.

    While I doubt I can make something that can cut metal, I bet I could design something that can cut a circuit board or engrave a 3D printed case out of this thing. However, in developing this idea I already started to run into scope creep and Theseus issues, so Rule #1: modify the printer as little as possible. This already provides design constraints: the heated bed and hotend account for 260 of the 350 watts available from the power supply, limiting my spindle choice to that or less. 

    To keep costs on this low and to further justify and enable my hobbies, Rule #2 is that I'll try to 3d print all parts using the assortment of engineering grade filaments I've accumulated over the last year. PA6-CF, PA6-GF, PPS-CF, or even something as mundane as ABS-GF could all provide enough stiffness with the right design.

    Looking over the system, I'll first remove the printer head in its entirety along with the bed and the extruder motor. That motor, being a 42-40 stepper, appears to produce greater torque while consuming more current than the 42-34 steppers driving the dimension axes on the printer. I plan on replacing the Z axis stepper with this 42-40, as the spindle will be much heavier than the print head to move and I'm concerned the smaller motor won't cut it. Additionally, I want to add an anti-backlash spring and nut onto the Z-axis lead screw to keep Z chatter to a minimum. Finally, I want to be able to rapidly swap out the spindle to a laser engraver with little hassle. Oh, and the electronics have got to go: the board is ancient, and no wifi, bluetooth, or USB connectivity is a dealbreaker. Maybe I'll reuse the control panel as a basic display and jogger setup, or maybe I'll keep it as a spare for the other working printer.