I’ve typically made my own printed circuit boards at home by etching them with chemicals, but the mill opens new opportunities to etch and drill the boards, so I gave it a shot. WiringOne of my goals with the Little CNC Milling Machine was to make my own PCBs. No other RUMBA-specific configuration is required. This informs Marlin of which pins correlate to the stepper drivers, thermistors, heater outputs - and so on. Changing it to 'BOARDRUMBA' (as above) is the main configuration step that is needed. By default, the MOTHEROBARD will be set to a RAMPS variant.
![]() Oops! Well, the holes didn’t all work. When I thought the board was cut out enough I pulled it off the machine.The board held up to the light. I might want to use a different bit next time. I’ll definitely use a different bit for the final cut next time.Here’s the final board. No matter, the amount of board left was paper thin and it came right out. Not a big deal for this board, as it would be easy to cut out on the band saw, but more complex boards may not have this luxury. Not great.I also didn’t cut all the way through with the outside profile. I ended up using my Tiny Drill Press to finish the holes, and it didn’t work very well as it was difficult to hit the center. What is the best video recorder for macMilling also allows me to have a PCB in an hour or so, versus waiting a few weeks.Of course I’m (sort of) limited to single sided boards, but most of my PCBs are pretty simple, so I’m not concerned yet. OSH Park does a great job and prototyping PCBs, and Seeed Studio is great for production runs, but I’ll probably mill any new boards I want to test out before sending out to a fab house. This probably won’t be the method I use for all my boards. The only issue I had was once I tried running it nothing was happening. No stripping, cutting or crimping wires. Here’s Part II!The electronics didn’t take much time at all, it was pretty much “plug and play” as far as connecting the three stepper motors and the spindle. Ramps/Rumba For Osx Software To ControlI’ve not really tried that yet, and have to figure out the software to control it first. Yes, there’s also a 500mw laser that can be put in place of the spindle. One nice thing about these machines is that if you make a mistake, like jogging the head too far in one direction, you can just cut power to the motors and the software will keep going, assuming the motors are moving, and then once the software is done, you can resupply power and try again.Oh, you might also notice that next to the spindle connector on the board is a spot to plug in the laser. I may add an e-stop, or just an “on/off” switch for the power supply. (Maybe a 3D printed piece, not sure yet.)You might also notice I left the lead screws hanging in mid-air. I’ll work on a better clamping system. Attaching things with the screws meant to attach things to the Aluminum extrusion is not great. Overall I have to say I’ve been pleased with this machine (so far, it’s still early, obviously.) It was easy to put together and it works. I’ll cover that in the next post. I think I’m good!And yes, I did actually mill something. I’m pretty sure I’ll lose the screws, but……luckily a few years ago my friends at Evil Mad Scientist Laboratories sent me a lifetime supply of M3 set screws of various sizes. It also came with super-small set screws. I think it’ll work fine without them, as the lead screws are not that long.The machine came with two tiny collets that allow you to attach bits to the spindle shaft. I’m hoping to mill PCBs with it, and other small things. (I guess I’m one of the first customers?) I was attracted to the mill because it’s small (my workshop is cramped already) and it runs Grbl. While I would have loved to have attended the class, I couldn’t make it, but I got in touch with Alex to ask a few questions, and the next thing you know I’m ordering a kit from him.Alex said he’ll be doing another class, and hopes to sell these to other people as well. I didn’t order from any of those sellers…Somehow I happened across a blog post at TC Maker about a CNC Building Class at The Hack Factory. I’ve seen these on eBay from various sellers (like this, this, this, and this) and I’ve even seen one on Amazon from LinkSprite. I should mention that these kits come from different sellers, and they all seem just a slight bit different. Luckily, there’s the Internet.The page titled DIY CNC 3 Axis Engraver Machine PCB Milling Wood Carving Router Kit Arduino Grbl is helpful, as is the video LinkSprite DIY CNC 3 Axis Engraver Machine installation tutorial. At some point the instructions seem to lose their usefulness and you just have to figure things out. I did get a construction manual, and it was helpful, though in the end it sort of reminded me of building my RepRap. Remember, Alex does an entire class on building this, which I did not attend, but I’ve built a few CNC machines in the past, so I wasn’t too worried. But first I have to get it working… I still have the wiring and electronics to deal with.I’ll go through a bit more about building it in this post, and probably follow up with a few more posts once it’s complete.First, let’s talk about the instructions. (Oh, before I over-tightened/stripped it, I tried to put a little tape on the rod. After I sent an hex key flying across the room, I tried one more time to tighten it up enough by putting a Torx bit in a drill (I know, bad idea.) This just stripped out the screw, and now it’s in there, and not coming out. I tried to tighten it up on the rod, and I could not get it tight enough to hold the rod. The one on the front right was the first I dealt with. Now, I’ve used rod holders before to hold smooth rods, and didn’t have issues, but these caused me some heartache. Again, use them as loose guides.The worst problem I had during the mechanical build was dealing with the rod holders. (It doesn’t wobble, but I was able to rotate the rod when it was just in the front holder.
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