Summary
A rigid, reliable miniature CNC mill that can work with many types of materials such as copper-clad FR4, wood, aluminum, brass, and copper. It has robust features such as NEMA 23 steppers, a 500W BLDC spindle, 20mm thick fixture plate, ballscrews and linear rails.
Side Note: Initially this was going to be ONLY a PCB Router, however midway I wanted to expand its functions
June 21
The first day! I researched extensively about CNC routers and mills, as well as their functions because a CNC router is the basis for a PCB router. Turns out there are a lot of parts to a CNC router. First, I decided whether to use a moving gantry or a moving bed. In this case, I opted for the moving bed due to its higher rigidity. And so, I got to work researching the basic parts such as the 24V power supply, the brushless fan for cooling, the SKR mini v3 board, a Genmitsu 775 spindle motor, and the 2004s1 stepper motors. I was thinking of adding a screen or a small control panel later on after the minimal viable product was complete. Other hardware parts included the linear rails, lead screws, extrusions, filament type, bed type, and thumbscrews. I decided to go with a 200mmx200mm bed size as that would be plenty for PCBs and it would also stay quite compact.
After that, I started working on the CAD. I added the 2020 aluminum extrusions and made a joiner plate. The extrusions were 200mm long and I went with them over the 2040s due to the rigidity increase probably being overkill as well as it getting significantly bigger. I also realized that I would need an M5 tap to be able to join the extrusions well which is fun.
Time Spent: 5 Hours
June 23
HUGE amounts of work were put into the CAD and overall design today!!! I finished almost the entire Y axis. All that's needed left is the mount for the stepper motor and the bed itself! Overall I'm really proud of how clean and sturdy it looks right now and how much progress I got done.
Time Spent: 6 Hours
June 25
The entire Y-axis was finished today!!! I thought this finishing part would be easy, but I had to make a few adjustments to get it to fit together nicely. First, I replaced the upper 3d printed parts with extrusions to make it stronger. I then made the stepper motor mount (and made it level with the ground so there would be zero flex, and rigidity would increase). After that, I polished up the whole thing to fit a bit better and added corner brackets and moved things around a bit. Finally, I finished up by making the bed which has M6 threads spread out evenly so I can use a thumbscrew clamp system to hold down the PCB being machined no matter the size. (The holes in the middle are for the movement system itself and then the small ones on the edges are for the linear rails)
Time Spent: 5 Hours
June 29
Turns out I forgot to add limit switches so the y-axis wasn't actually finished until TODAY. It was kinda hard visualizing all the mechanisms but it should all be good now. I started work on the upper part as well. It seems like the router might be a mill due to it looking like it will be very rigid.
Time Spent: 5 Hours
July 27th
After finishing various other highway projects and going to Undercity, I've changed the entire scope of this project. It's still going to be a PCB Mill, but I want it to be small, and rigid enough to do aluminum as well. Today I've scoped out new parts, including a 500W spindle and ballscrews. I've upgraded every single part of this from the nema 17 steppers to the nema 23 steppers, from 3D printed parts to aluminum machined parts. I estimate the whole thing would cost around $750, however, I think I will be able to whittle it down.
Today I made the base of the y-axis without doing any of the mounting and stuff, but it's looking decent (and finally rigid)
Total Time Spent: 3 Hours
July 28th
Started off the day by adding the supports and ballscrew nut/housing as well as adjusting the whole thing.
Added lots of mounting plates in order to keep the rigidity levels high- using a bunch of 2020 extrusions was a LOT cheaper than using stuff like 2080s, etc. I was able to find a deal at around $2.2 per 300mm 2020 extrusion, which is really good in 10 packs.
Eventually I finished all the mounts, layout, etc. Which took a lot longer than expected. But it looks solid and rigid, as well as being actually precise.
Total Time Spent: 4 Hours
July 29th
Highway's final stretch, I should be able to finish this by the end of tomorrow and be able to ship before the end of highway. I finished up the entire y-axis, with the fixture plate, mounts, adding more extrusions, joining plates, and a limit switch.
Took ages to add all the support but im ready to implement the movement system in here.
I actually made two different designs for the x-axis but I settled on the photo below because it was the least pricy and most rigid. I was originally going to use custom milled plates but I realized it's just not worth it. This took me the whole day unsurprisingly (making a rigid mill is HARD) but I'm super excited to start milling aluminum, brass, and copper on this thing!
It's almost done! I think I'm gonna finish it tomorrow morning.
Time Spent: 6 Hours
July 30
Today I almost finished the whole x axis except I'm thinking through how to mount the motor, I'm really not quite sure but everything else on the x-axis is mounted and designed correctly so far.
Luckily I solved that problem. And without 3d printed parts too (that would be bad)
Completely finished the x axis and added the z axis! All that's left is mounting the spindle clamp to the rails/nut. It's looking really nice, building this is gonna be a blast.
I finished everything.. I think. Now time for power, wiring, etc. The mill itself is looking insanee tho.
I cleaned up and finished the BOM which once I added up the prices I was horrified. It should be fine, though.
Finished up the wiring diagram!
I spent a good while rendering, I don't wanna spam the journal with all 50 renders but I'll put a couple random ones in.
Finished up the BOM, Readme, etc. The final journal entry, as the project is now finished.
Time Spent: 12 Hours