There are probably almost as many DIY CNC designs as there are DIY CNCs. And there’s nothing wrong with that! We really liked [maxvfischer’s] documentation on GitHub for a machine he made based on a design by [Ivan Miranada].
In addition to a complete bill of materials, there are Fusion 360 files and very good instructions. There are several tips that seemed like they would help even if you were building similar machines.
The machine uses HTD5M belts instead of the more prevalent lead screw design. Everything slides on MGN12H slides. There are detailed photographs covering not just the tricky parts but even how to extend the stepper motor wires.
The original design used a Makita RT0700C for the spindle, but [max] couldn’t find one of those, but found a similar version with the same dimensions.
The only tip we would add is to be careful using taps in a handheld drill. (Don’t ask us how we know that.) A drill press is safer, or you can even use a tap handle and do it the old-fashioned way.
The firmware is grbl on an Arduino, and there are complete instructions for setting that up, too. We were amazed at the number of pictures included along with the detailed description. If you were ever afraid you couldn’t duplicate a CNC project, this might be the one to tackle.
There are, of course, cheaper and simpler options with fewer capabilities. Some are even almost free courtesy of the local dumpster.
NICE documentation. I also especially like that it doesn’t use expensive extrusions. Yeah, a little more work drilling, but it’s obviously a labor of love.
It will also be far far stiffer than extrusions – you get a better machine, cheaper all for the effort of drilling and tapping some holes – I’m hoping to do similar but use steel and epoxy with sand/gravel fill for a much tougher machine that fits my space this year, maybe next – all down to finding time/space and money…
I’m not entirely sure that box tubing is stiffer than 8020 extrusion, but I think it’s a no-brainer that epoxy-granite or epoxy-sand filled box tubing would be! Don’t know why I didn’t think of that. When I think epoxy-granite, I think of the challenges involved in making forms to fill with the composite, but now…
You could even try using tensened cables to further stiffen your tubing. You would have to plug one end, attach cable running whole length of tubing, pour your chosen epoxy-granite, then pull those cables with rather high force (by attaching it to steel frame and tightening cable using bolt and nuts) and wait for curing. After curing, additional stress will further stiffen your tubing and damp some vibrations.
8020 is really free to twist and its easier to bend than the same wall thickness and size square tube too – its effectively a small round tube with tabs to make it square profile attached – so in effect for many loads its not really working on anything but the tiny round tube in the middle, not saying you cant make good machines with it but between how easily it can be twisted and bent you have to be much more careful with geometries adding in constraining wires or more extrusions to counter that tendency.
When you put it that way… yeah.
It is not a DIY CNC, it is using grbl for that. It is however a DIY CNC router.
Thank you for saying this so I didn’t have to.
“CNC” means Computer Numerically Controlled machine, just as “Drill” means Drill machine. But even if you don’t accept that, CNC involves more than the microcontroller board. It includes the computer that is actually serving the G-code and the motors that are moving the workpiece and or tool. I don’t think that it’s a stretch to call the integration of these devices into a working system “DIY”. I’m not saying it’s particularly difficult; I’m saying he did it himself.
The problem is that they’re referring to the machine as “a CNC.” CNC is “Computer Numerical Control,” not “Computer Numerically Controlled machine.” Quite often you’ll hear people talk about “a CNC” or saying they’re “going to CNC” something, both of which leave out what the actual type of machine it is. Most of the time, they seem to be assuming that “CNC” means “router” or “mill,” which it doesn’t. Proper usage would be talking about a CNC router, CNC mill, CNC lathe, CNC laser, CNC plasma cutter, etc. A recent article mentioned a process they called “analog CNC” because they did all the cuts by hand, which was especially egregious.
The counterexample I’ve been using lately is saying that I made something on my manual. That tells you the same amount of information about the machine and process I used as saying I made it on my CNC.
The problem – the only problem – here, is that you don’t have control over how the language gets used. We all know what someone MEANS when they say “CNC”, even if they don’t paste “machine” onto the end of it. That’s all that matters. If you’re going to get bent out of shape every time something in the language doesn’t make sense to you, you’re just going to have a tough time.
And by the way, your “counterexample” just demonstrates that it’s more important to you to make a (pointless) stand than it is to communicate with people. If you say you “made something” on your “manual”, you are making a statement that you intend not to be understood. Do you think this is going to make the rest of the world use words in a logical way? Hint: they’re not. Ever.
I’ve tried making a stand on the use of “twice as slow”, “250% less”, and similar nonsense. There really is no winning these fights.
It is more like people do not actually understand the words they are using. i.e. They pick a word because they like what it sounds, not what it means.
I see that a lot when I see people saying all kinds of senseless things like “line of site”, “copy write” without understand what each of the words means.
Using battery powered drill for tapping seems like good idea, most problems I had with tapping with manual handle were from unequal force distribution. Using something big helps with stability.
Check out rootcnc
https://rootcnc.com/
It’s a similar but more mature project, it has the aluminium at 45 degrees for rigidity
Seems like the 45° angle is to get the wheeled carriages to track well and self-center, putting weight on two faces at an angle to each other.
While it would remove play from the motion (provided machining forces are less than the weight of the carriage) which is good, I don’t see how it could increase the rigidity of the frame.
Spiral point taps and spiral flute taps will perform well in a drill. Conventional hand taps will break handily.
And cheap crappy taps will break as soon as you look at them next to a vaguely hard material to cut, no matter how you use them (well not quite, but its one area where cheaping out really won’t pay you back as it will break and take you ages to extract or scrap the part)..
Calling this a “CNC” is like calling an electric drill an “electric” without identifying the type of thing it is. A 3D printer is just as much a “CNC” as a router, as is a CNC lathe, CNC mill, CNC robotic arm, etc., etc.
Many people misuse the term “CNC” to mean “CNC router”.
I would argue that it is like calling an electric drill a drill. CNC is a controle process like drill is a machining process yet people still know what you want when you ask for a drill.
CNC is a control process, not a machining process. By calling any CNC-enabled machine “a CNC,” you’re leaving out the information about the fundamental process you’re after. I can cut a mortise in a chair leg with a regular router or a CNC router, but cutting a mortise in a chair leg with a CNC lathe is a less-good idea.
When describing a tool, CNC is an adjective, not a noun or verb.