Z axis for CNC mini mill

thingiverse

This is a blueprint for crafting a Z axis for a CNC mini mill. Initially, I possessed a milling table, Dremel, CNC shield, and some motors collecting dust, when I spotted a mini CNC mill within them. Since I merely required a Z axis, I fashioned one out of square steel tube (20x20mm). The components were connected with 3D printed parts made from ABS. The assembly's purple hue stems from the abundance of that color I had available. The spindles and guiding rod are M8 in size. Using model "Nema 17 bracket for milling table," I linked the steppers to the milling table. For these brackets, please refer to: https://www.thingiverse.com/thing:2720575 With these components at my disposal, I constructed this mini mill. Given that the table can only move 80 by 80 mm, it's not particularly large. However, if one were to employ a larger table, they could easily increase the size of the X and Y axes. As my controller, I utilized an Arduino Uno paired with a CNC shield featuring DRV8825 drivers and GRLB python script found on GitHub (https://github.com/grbl/grbl). In this case, I simply employed universal Gcode sender for transmitting the Gcode (https://github.com/winder/Universal-G-Code-Sender). The Gcode and paths were created using Inkscape (https://inkscape.org/en/). My initial test was conducted on a MDF plate, but it didn't yield optimal results due to my lack of an appropriate milling bit for the Arduino. The second test involved an acrylic plate, but the milling bit did more melting than actual milling. I suspect that using a cooling liquid would have improved the outcome. During my third test, I utilized an aluminum plate and achieved better results except for the fact that my mini Dremel bit flexed slightly during milling. My fourth test was milling a PCB and it worked well, although I still need to refine my Gcode. The mini mill performs admirably. The motors didn't skip any steps due to EMF frequencies generated by the Dremel brushed motor. To mitigate this issue, I employed a DIY mains filter. If you're interested in this mains filter, feel free to ask. As an added precaution, I even had a 1:1 1KVA transformer on hand, but it remained unused. I opted not to utilize end switches due to the potential for EMF issues they could introduce. Additionally, I chose not to shield anything, adhering to the principle that "less is more." For micro stepping, I settled on 4 micro steps for the X and Y motor to avoid any complications. If you have any questions or concerns, please don't hesitate to ask.