Been obsessing over the MPCNC ever since I first saw the plans a few days ago. I wish I could remember where I saw it mentioned, but as soon as I saw it I wanted to build it!
My background: I have zero experience with CNCs. I’ve been 3D printing almost daily for over a year with several materials successfully. I live within city limits and do not have a “workshop” per-se, just an office with a work area, but I do have a dry basement with a corner where I keep my tools (belt saw, dremel, etc. minor stuff). Noise is a concern, which is the only thing holding me back from building.
My MPCNC goals, in order of what I believe would be a natural order of progression:
Pen plotter. It's quiet, and I can't draw - so why not let a machine do it for me?
Drag knife for vinyl/paper.
Foam cutter for DTFB/Flite Test planes. This means my usable build area needs to be at least 20"x30".
Laser cutter/engraver (because frickin' lasers). This is the ultimate goal right now, since I imagine it would be quiet but would still achieve 80% of what I would want to do.
maybe, perhaps, someday add a spindle for routing/milling. This would complete that 20%, but the noise/dust is probably a game stopper unless I had a workshop or soundproofed enclosure.
I already have some EMT conduit laying around, and I plan on printing the parts in PETG (0.4mm nozzle, 0.24mm layers, 3 outlines, 30-40% infill - I printed a foot with these settings and that part is TOUGH).
So my questions:
How feasible is it to build it at the size I need and be able to swap tools? I know it is best to "purpose build", and I believe my ultimate goal is a decent laser cutter for foam and thin wood (think model plane plans), so is the progression above acceptable?
I'm a little nervous about the laser (as one should be), but I really want to try it. As this would be in my basement, should I go ahead and plan/budget for an enclosure right off the bat? I've seen a few builds with what looks like a small laser shield right around the burn/cut area only - is that right? If done correctly, can that be used in lieu of a full enclosure? What about fumes, do I need to take a vent into consideration? There are windows in the basement near where this would be, I could probably vent out of one of those fairly easily.
I know very little design, but desire to and am willing to learn. I've designed some minor parts for printing in Fusion360, is that an okay program to start with? There's a lot I still don't know about it but don't want to invest time in it if there are better options. Plus it's free, so...
Knowing all I want to achieve, which board and power supply should I go with?
Thanks in advance, if this doesn't seem completely crazy I'll probably be ordering the electronics bundle soon.
Make the Z axis small, 2" or so. That size should be fine for anything you're wanting to do except milling. It will be possible to mill, but not easy. Luckily, by the time you get to that step, you can cut down your conduit and make it super rigid, or you'll know enough that you won't be frustrated with the troubles that sized machine causes at 2'x3' sizes. My first machine was for milling and it was a cutting area of 24x36 and I loved it, even if I failed a few cuts.
I think fumes are the biggest concern. If you're carving wood, the particles are smaller than say, a fireplace (which I think is bad) and even still, you wouldn't have a fireplace in your basement without venting it. If you're cutting plastics or foam, then that stuff gets nasty. If you need to enclose it to vent it, then that would be where I would start. You don't need it to pen plot though, so you could just build the table with an eventual enclosure in mind.
Software is harder than with 3D printing. The process is: CAD, CAM, gcode sending.
For CAD, there are many many options. There aren't as many designs for CNC as there are for 3D printing, so you're going to be doing more CAD yourself. Since you'll be doing just 2D stuff for the foreseeable future, I would use Inkscape for anything artistic (like taking a bitmap and converting it to an svg for pen drawing) and I'd use librecad for anything dimensional. Fusion can do 2D drawing, but it's very complicated software for what you need. I also prefer Onshape to Fusion for 3D stuff (but that's me).
For CAM, do yourself a favor and start with EstlCAM, and follow the tutorial on this site. Fusion can do CAM and there's a post processor for the MPCNC, but there aren't as many people on the forums to help, and it's significantly more complicated.
For gcode sending, you can buy the LCD, which has an SD card reader. People recently have been reporting issues with repetier-host, but that's been a popular choice for a long time. You can also use octoprint/octopi, which you'll probably really enjoy when you are doing the less dangerous stuff and want to monitor it from somewhere else.
You don't need the big power supply, that's for the heated bed of 3D printing (and your machine will be a terrible size for 3DP). On RAMPS vs. Rambo. The Rambo is tough as nails (hard to short, you can accidentally install the power backwards and it won't die, replacable fuses). The RAMPS is really three parts, the Arduino, the breakout board (RAMPS 1.4) and the drivers (drv 8825). If you get the RAMPS from Ryan, it comes assembled and flashed, which is a big advantage over buying the stuff on amazon or something.
The parts were designed and tested well in PLA. PETG won’t break easily, but it does flex a bit more. It does have higher heat tolerances though. I printed mine in PLA, and the one part I reprinted in PETG was the X/Y Motor mounts (because of the heat the motors made). Just keep that in mind.
Thank you Jeff! It sounds like I have some thinking to do then - the more I read the more I realize that a 2.5W laser isn’t a good choice for cutting. From what I can tell I’d want at least a 40W, and that is not a leap I’m willing to make for this project. So now I’m looking at a $400 pen plotter/vinyl cutter/needle cutter for foamies. Convenient, yes, but I’m not sure I can justify the cost based on how little I fly these days.
It all depends on what you want to cut, and what your patience is. You can do some significant damage with a 2.5W laser, but it’s not an epilog, that’s for sure.
Stew on it a bit. Don’t forget to add in the value of the process. It’s so satisfying to make it work from a spool of plastic and some motors. Also, a lot of the costs, like the controller and the motors are good for other things, like other CNC machines (I converted my MPCNC into a Low Rider), a 3D printer (that’s where the parts are supposed to go), or a sand table.
I hope I didn’t frighten you. It is a lot of fun, but maybe I’m a glutton for punishment
So realistically I could cut at least 3mm balsa with the 2.5W? Is there a thread what covers what does and does not work? I’d like to be able to cut clear acrylic maybe. would a 3.5W diode be a better choice?
I’m not scared off at all, a big part of my desire to build is just for the experience, but a budget is a budget This is my hobby money, so it’s this or some other cool toy, lol.
I think if I start with the idea of building a plotter/drag knife/needle cutter I can try the laser later when I refill the coffer.
If PLA really is the way to go, then so be it. It is cheaper than PETG at least.
Clear acrylic requires a Co2 laser. These small visible lasers just pass right through anything clear. The Co2 has a wavelength >10000nm vs these small ones at 4-500nm.
I just went through that exercise explaining to my mother why I can’t cut out all this crap she wants. Funny thing about these machines is when you tell people you have one they all want projects done but things that are way outside the capabilities of it…
I agree with Jeff, just building something like this is a worthwhile project. I love machines. I’ve built R/C helicopters and all kinds of stuff from scratch… then never use them after they are built. The fun for me is in the building and making it work.
They day after I first test the MPCNC, I went to work and said “Dude! I made this CNC thing, totally open ended. You could make it any size you want so far I have a 2’x2’ CNC on my living room table. 2’ that is insane right?!?” my coworker, the first person I told says “Can you make me a 4’ engraved circular sign?”
I was a little bummed. It took the wind right out of my sails. I have been very careful with my words ever since. Glad I said no, that would have taken forever especially back then with the dremel.
I can live w/o cutting acrylic. If I can laser cut some firewalls and control horns from thin hobby ply, cut the foam, and make some decals I think I’d be happy enough for a while without a spindle.
Yeah but look at you now! Created a small little home CNC empire. That is about as badass as you can get in my book! I was scraping money together to buy an Xcarve when I came across your machine… I get to have a CNC and build it myself! Sold!
No joke, I told her exactly that! Told her how easy it is to make one that is like 20" square and she can mount whatever cutting tools she wants to it. And even fork out the cash for a Co2 if she wants. I sent her the link to this website and told her to have at it. haha
Personally, I use mine for cutting/engraving/milling wood with the DeWalt and the 2.8w laser for cutting thin/soft wood, vinyl, burning images (greyscale photos/drawings) and my latest favorite - using it to ablate the back surface of mirrors to make some pretty cool art projects. Best money I’ve spent in a long while and I’ve made the wife enough goodies that she even agrees, which is rare!
I’m also about to pull the trigger and make a machine mostly for Foamboard RC planes. Are the FAQ and INFO pages down or something?? I wanted to buy lumber this morning and get started on the table, parts are printing now, and I’m buying the hardware kit this week. What size bed do I need? How much conduit? Help a noob, please?
I mentioned that I was going to be building a CNC at work and was asked I could etch a brass memorial plack for someones love one, I don’t know people are cutting aluminum but has anyone etched other metals I would like to do this but will decline if not possible the plate is 9 x 14
Me and my big mouth
Sorry for the post just struck me as funny (odd) about the expectations people have about the machines.
1-Table - V1 Engineering Documentation this link should have all the info you need in order, the conduit page has calculator links that will tell you table size and amount of rails.
Brass is entirely possible, it is expensive though, before you commit you should make some test cuts and look at powder coating the recessed areas or at least painting them. Brass is softer than aluminum but also more sticky.
Thanks Ryan!! Th Z-axis assembly page looks to be down, but the rest got me prepped for my trip to the hardware. I’ll be lurking around the forums forever now. LOL!
This is my hobby money, so it’s this or some other cool toy, lol.