Pen Plotter Draws Maps Directly On The Wall

For map-lovers like [Christopher Getschmann], poring over a quality map can be as satisfying as reading a good book. Good maps can be hard to come by, though, especially at a scale worth looking at, or worth using as adornment on a dull, lifeless wall. The solution is obvious: build a wall-mount CNC plotter to draw maps directly on the wall.

[Christopher] began his map quest by scraping world map data from a number of sources, including OpenStreetMap, Natural Earth, and GEBCO. This gave him data for coastlines, terrain, and bathymetry — enough for a map of the world large enough to fill a wall. Since the scale of the map would preclude the use of even a large-format inkjet printer, [Christopher] set about building a wall-covering pen-plotter to render the map. The CoreXY-style plotter is large, but still light enough to hang on the wall while it works, and to be repositioned to cover a larger area.

The plotter runs on steppers driven by ultra-quiet Trinamic TMC5160 drivers, so the plotter wouldn’t be a nuisance while it worked. The map was plotted on eight pieces of cardboard mounted directly to the wall, filling the 2- x 3-meter space almost entirely. Landmasses and elevation contours were plotted as continuous lines in black ink, while bathymetric data was rendered in blue ink as cross-hatching with variable spacing, to make deeper oceans darker blue.

We find [Christopher]’s map breathtaking, all the more so considering the work that went into making it. It would be interesting to find alternate uses for the plotter, which reminds us a little of a cross between a draw-bot and a Maslow vertical CNC router, now that it’s done with its cartographic duties.

Checking In On Low-Cost CNC Machines

Low cost 3D printers have come a long way in the last few years, but have entry-level CNC machines improved by the same leaps and bounds? That’s what [ModBot] recently set out to find. Despite getting burned pretty badly on a cheap CNC a few years back, he decided to try again with a sub $400 machine from FoxAlien. You can see his full review after the break.

The machine looks very similar to other generic CNC machines you see under many brand names, sometimes for a good bit less. The 3018 number is a giveaway that the work area is 30×18 cm and a quick search pulled up several similar machines for just a bit more than $200. The FoxAlien did have a few nice features, though. It has a good-looking build guide and an acrylic box to keep down the shaving debris in your shop. There are also some other nice touches like a Z-axis probe and end stops. If you add those items to the cut-rate 3018 machines, the FoxAlien machine is pretty price competitive when you buy it from the vendor’s website. The Amazon page in the video shows $350 which is a bit more expensive but does include shipping.

As with most of these cheap CNC machines, one could argue that it’s more of an engraver than a full mill. But on the plus side, you can mount other tools and spindles to get different results. You can even turn one of these into a diode laser cutter, but you might be better off with something purpose-built unless you think you’ll want to switch back and forth often.

This reminded us of a CNC we’ve used a lot, the LinkSprite. It does fine for about the same price but we are jealous of the enclosure. Of course, half the fun of owning something like this is hacking it and there are plenty of upgrades for these cheap machines.

Enormous CNC Router Uses Clever Tricks To Improve Performance

CNC machines made from wood and 3D-printed parts may be popular, but they aren’t always practical from a precision and repeatability standpoint. This is especially true as the machines are scaled up in size, where the compliance of their components starts to really add up. But can those issues be resolved? [jamie clarke] thinks so, and he’s in the process of building a CNC router that can handle a full sheet of plywood. (Video, embedded below.)

This is very much a work in progress, and the videos below are only the very beginning of the process. But we found [jamie]’s build interesting even at this early point because he has included a few clever tricks to control the normal sources of slop that plague larger CNC machines. To provide stiffness on a budget, [jamie] went with a wooden torsion-box design for the bed of his machine. It’s the approach taken by the Root CNC project, which is the inspiration for this build. The bed is formed from shallow boxes that achieve their stiffness through stressed skins applied to rigid, lightweight frames.

Upon the torsion-box bed are guide rails made from commodity lengths of square steel tubing. Stiff these may be over short lengths, but over the three meters needed to access a full sheet of plywood, even steel will bend. [jamie]’s solution is a support that moves along with the carriage, which halves the unsupported length of the beam at all points of travel. He’s using a similar approach to fight whip in the ball screw, with a clever flip-down cradle at the midpoint of the screw.

So far, we’re impressed by the quality of this build. We’re looking forward to seeing where this goes and how well the machine performs, so we’re paying close attention to the playlist for updates. At an estimated build cost of £1,500, this might be just the CNC build you’ve been looking for.

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How Much Is Too Much?

I definitely tend towards minimalism in my personal projects. That often translates into getting stuff done with the smallest number of parts, or the cheapest parts, or the lowest tech. Oddly enough that doesn’t extend to getting the project done in the minimum amount of time, which is a resource no less valuable than money or silicon. The overkill road is often the smoothest road, but I’ll make the case for taking the rocky, muddy path. (At least sometimes.)

There are a bunch of great designs for CNC hot-wire foam cutters out there, and they range from the hacky to the ridiculously over-engineered, with probably most of them falling into the latter pile. Many of the machines you’ll see borrow heavily from their nearest cousins, the CNC mill or the 3D printer, and sport hardened steel rails or ballscrews and are constructed out of thick MDF or even aluminum plates.

All a CNC foam cutter needs to do is hold a little bit of tension on a wire that gets hot, and pass it slowly and accurately through a block of foam, which obligingly melts out of the way. The wire moves slowly, so the frame doesn’t need to handle the acceleration of a 3D printer head, and it faces almost no load so it doesn’t need any of the beefy drives and ways of the CNC mill. But the mechanics of the mill and printer are so well worked out that most makers don’t feel the need to minimize, simply build what they already know, and thereby save time. They build a machine strong enough to carry a small child instead of a 60 cm length of 0.4 mm wire that weighs less than a bird’s feather.

I took the opposite approach, building as light and as minimal as possible from the ground up. (Which is why my machine still isn’t finished yet!) By building too little, too wobbly, or simply too janky, I’ve gotten to see what the advantages of the more robust designs are. Had I started out with an infinite supply of v-slot rail and ballscrews, I wouldn’t have found out that they’re overkill, but if I had started out with a frame that resisted pulling inwards a little bit more, I would be done by now.

Overbuilding is expedient, but it’s also a one-way street. Once you have the gilded version of the machine up and running, there’s little incentive to reduce the cost or complexity of the thing; it’s working and the money is already spent. But when your machine doesn’t quite work well enough yet, it’s easy enough to tell what needs improving, as well as what doesn’t. Overkill is the path of getting it done fast, while iterated failure and improvement is the path of learning along the way. And when it’s done, I’ll have a good story to tell. Or at least that’s what I’m saying to myself as I wait for my third rail-holder block to finish printing.

CNC Router Frame Repurposed For Colorful String Art Bot

Pandemic lockdowns have been brutal, but they’ve had the side-effect of spurring creativity and undertaking projects that are involved enough and complex enough to keep from going stir crazy. This CNC string art robot is a great example of what’s possible with a little imagination and a lot of time. (Video, embedded below.)

According to [knezuld11], the robot creates its art through mathematical algorithms via a Python program that translates them into nail positions and string paths. The modified CNC router frame, constructed of laser-cut plywood, has two interchangeable tool heads. The first places the nails, which are held in a small hopper. After being picked up by a servo-controlled magnetic arm and held vertically, a gear-driven ram pushes each nail into a board at just the right coordinates. After changing to a different tool, the robot is able to pick up one of nine different thread dispensers. A laser sensor verifies the thread nozzle position, and the thread starts its long journey around the nails. It’s a little mesmerizing to watch, and the art looks great, with a vibe that brings us right back to the 70s. Groovy, man.

This reminds us a little of a recent [Barton Dring] project that makes art from overlapping strings. That one was pretty cool for what it accomplished with just one thread color, while this one really brings color to the party. Take your pick, place your nails, and get stringing.

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A Case For Project Part Numbers

Even when we share the design files for open source hardware, the step between digital files and a real-world mechatronics widget is still a big one. That’s why I set off on a personal vendetta to find ways to make that transfer step easier for newcomers to an open source mechantronics project.

Today, I want to spill the beans on one of these finds: part numbers, and showcase how they can help you share your project in a way that helps other reproduce it. Think of part numbers as being like version numbers for software, but on real objects.

I’ll showcase an example of putting part numbers to work on one of my projects, and then I’ll finish off by showing just how part numbers offer some powerful community-building aspects to your project.

A Tale Told with Jubilee

To give this idea some teeth, I put it to work on Jubilee, my open source toolchanging machine. Between October 2019 to November 2020, we’ve slowly grown the number of folks building Jubilees in the world from 1 to more than 50 chatting it up on the Discord server. Continue reading “A Case For Project Part Numbers”

Scratch Building A Supersized CNC Router

Many of us have spent the better part of a year on COVID-19 lockdown, and what do we have to show for it? Bit of progress on the Netflix queue? Maybe a (slightly) cleaned up garage or workshop? Not if you’re [Bob] of Making Stuff fame: he’s spent the last nine months working on a completely custom CNC router big enough to take a whole sheet of plywood.

The build is documented over a series of nearly a dozen YouTube videos, the first of which was put out all the way back in January of 2020. Seeing [Bob] heading to the steel mill to get his frame components with nary a mask in sight is a reminder of just how long he’s been working on this project. He’s also put together a comprehensive Bill of Materials on his website should anyone want to follow in his footsteps. Coming in at only slightly less than $4,000 USD, it’s certainly not a budget build. But then when we’re talking about a machine of this scale, nothing comes cheap.

Every component on this build is heavy-duty.

Even if you don’t build you own version of this router, it’s impossible to watch the build log and not get inspired about the possibilities of such a machine. In the last video we’re even treated to a bit of self-replicating action, as the jumbo CNC cuts out the pieces for its own electronics enclosure.

You can tell from the videos that [Bob] is (rightfully) proud of his creation, and isn’t shy about showing the viewer each and every triumph along the way. Even when things don’t go according to plan, there are lessons to be learned as he explains the problems and how they were ultimately resolved.

Of course, we know a home-built CNC router doesn’t need to cost thousands of dollars or take up as much space as a pool table. The average Hackaday reader probably has no need of a monster like this, and wouldn’t have anywhere to keep it even if they did. But that doesn’t mean we can’t look on with envy as we wait to see what kind of projects [Bob] churns out with such an incredible tool in his arsenal.

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