While I think 3D printers are amazing, my heart has always leant towards CNC routers. I guess when it comes down to matter, I’m more of a substractive synthesis animal.
Window shopping
After I had a look at the big devices with many axises doing amazing things on video platforms, I saw that the prices went very high very quickly.
While I have wanted a CNC router for a long time, it was a diffuse desire until I realized that there is one thing I wish I could do at home, and that a CNC router could do: home-made PCBs.
Copper and epoxy dust versus toxic chemicals
The one thing that I dislike about making PCBs is using chemicals to etch the circuits. Honestly I think the whole process is tedious in addition to being dangerous. Many steps, many chemicals to buy, use, safely keep and dispose of.
Etching a PCB with a CNC router produces copper dust but it seems like a less annoying process overall. It might be less precise too, but for my needs I think it should be enough.
3018
So there is a load of 3018 CNC routers on Amazon and Aliexpress. 3018 is the size of the bed: 30cm × 18cm, that’s the horizontal area that the CNC router can process. Vertically though that’s like, 4.5cm tops so it’s not great. Again, enough for my needs. More importantly: they are cheap!
Vevor makes some of the cheapest, if not the cheapest, CNC routers in this category, so I went with that. Bonus points: some packages come with a spindle for milling and a small laser for engraving! That’s neat, I can mill my circuits and engrave the other side of the PCB with the silkscreen!
This Vevor 3018 Pro is only 166.99€ at the time of writing. It’s also on AliExpress. For some reason the milling module is not on the picture but it is in the package. Interesting feature: it’s easy to change between modules.
The next price level is almost thrice as high and it’s already too much for my budget, so I’m going with this one, which has ok reviews. Some people are making videos talking about it, its qualities and shortcomings and how to mod and upgrade it, so it has a little community which is great.
Plus, it is said to be able to mill PCBs and there are a few videos demonstrating that it indeed can! But slowly…
Why so cheap
The catch is: everything in there is a little underpowered. You have to cut costs somewhere to reach the lower prices, I suppose! The stepper-motors aren’t very powerful and they might skip if you’re milling too hard, the spindle isn’t very fast, the laser isn’t very powerful.
Fortunately in most cases you can still mill or engrave harder materials by taking it slow. So I’ll just go slow and everything should be fine!
And then I bought the machine and waited for it to be delivered to my door. It came from Czechia!
Assembly time!
I invited Kooda and Morkheleb to the assembly party and I streamed the whole thing on my channel on Picarto! It took us 2 hours and a half to complete the CNC router; here is a 5 minutes timelapse for your enjoyment:
That was fun! The instructions were clear enough, nothing too annoying. The finished product feels sturdy enough!
I kept getting grease on my hands, I hope I didn’t remove too much from the rods. I think I’ll buy some appropriate grease eventually to add some to the rods.
First production
At the end of the video you can see I use the little control module to move the spindle and verify everything’s working fine. This little module can actually read G-Code1 files on a SD card and operate the CNC router on its own! There was a few example files on the provided SD card, so I put the laser module, put some carboard in there, and burned something!
During the process, the laser was moving up and down, which is a sign that the file was instead intended to be used with the milling module. But I was still happy that we succeeded in assembling the machine!
We also had a good surprise: although I ordered the package with the 500mW laser, the one I received is rated for 5W! I’m pretty sure they made a mistake but I won’t complain :)
Tired of watching the world burn
So I’m just gonna burn more cardboard, but this time with my own files!
The recommended software, LaserGRBL, ain’t built for Linux. And it crashes when running on wine :(
I think bCNC would work, its latest version now has a laser engraving plugin that will produce suitable G-Code, but it has to be directly connected to the CNC router to work. It wouldn’t load my SVG file anyway.
Then I stumbled upon LaserWeb, and it did the one thing I needed: convert my picture to laser-operating G-Code. And I didn’t even have to install it, it runs in my browser2.
Here comes the boy~
So I chose a picture, made some filtering to keep only the outlines in Gimp, vectorized that picture with Inkscape, and imported the resulting SVG into LaserWeb:
It’s based on a picture of Kooda’s skunk fursona, drawn by C.C.Art!
After generating the G-Code, focusing the laser on the surface and positioning it at its home position, I used the WiFi interface of the control module (!) to upload the file to the SD card and then burn that cardboard!
Ho boy it looks great! Very thin line, very precise. Gorgeous!
Hidden Hiccups
Aside from finding the correct software for my use-case, this happened:
Calibration
Speed and laser power depend on the material you’re burning. My first laser engraving did work, but it was barely visible because I didn’t put enough laser power and the speed was too high. I had to make a few additional tries to get it right.
Little hardware problem
At some point the Y axis started randomly getting stuck. On one instance it stopped working until the end of the engraving and I thought the G-Code was corrupted.
When I saw the G-Code looked fine on the SD card, I tried fiddling with the Y axis using the Y knob and noticed that there was some slack… then I realized the Y stepper-motor wasn’t correctly fixed to the Y axis rod. I had to do a little disassembly to tighten some screws and then everything was fine again!
Fasten your belts!
You might have noticed that the above image is quite wobbly… Well I didn’t think I had to fasten the cardboard to the machine’s bed because the speed was low and I wasn’t milling… but that’s what you get when you don’t :D
Some people online grumble about how abysmal those clamps are, but I think they’re okay! Maybe I don’t have anything else to compare those to :D
Funny Firmware
The control unit is cute and all, but it has a little quirk: when you delete files on the SD card, they still appear in the list, with “error” as their file name… The FAT32 driver might need more testing! Strangely enough, the problem doesn’t appear in the web interface, where deleted files don’t appear at all.
printf would have said
(null)Little reminder that on a FAT system, one deletes a file by putting a 0 character in place of the first character of the name of the file. The entry is still there until it’s replaced with a new entry for a new file; we used to be able to undelete files by putting back the missing first letter of the file name (and maybe get some parts of it corrupted, or double-allocated).
I guess the driver in the control module interprets that as an empty string and some code somewhere isn’t happy with the empty string and prints “error” instead.
All-in-all
I’m pretty happy with my purchase! I’m gonna do a little more laser engraving until I get confident enough with my tools and obtain some material to try and mill and eventually make a PCB for one of my other ongoing projects with Kooda, and another one for myself that I have been procrastinating for years!
In the meantime, have a picture of my fursona drawn by Reptifur burnt on cardboard!
And to wrap it up, two close-up’s in macro mode to appreciate the precision and quality of the burning:
G-Code is a text format used here for operating the CNC router. It’s a list of movements that the CNC router will do, with associated speed, spindle rotations per minutes or laser power level. It looks pretty simple!↩︎
It will also run from a docker image on Linux or be installed on Windows or macOS, and it will then be able to connect to the CNC router directly and operate it.↩︎