Wooden Game Boy Is A Challenging Intro CNC Project

November 4, 2023 by Dan Maloney 12 Comments

[Sebastian] describes himself as “a total noob” when it comes to CNC, so in an attempt to get to know his new CNC router, he chose about the most complex possible project — replicating an original Game Boy case in wood. And spoiler alert: he nailed it.

Of course, he did have a few things going for him. At least from a straight woodworking perspective, it’s hard to go wrong by choosing walnut as your material. Then again, it can be unforgiving at times, and picky about tooling, which is probably why [Sebastian] used nine different tools to get the job done. But where he upped the difficulty level was in reproducing so many of the details of the original injection-molded plastic case. There are top and bottom shells, each of which has to be milled from both sides. This makes registration tricky when the parts are flipped. Specific indexing holes were used for that, along with the old “blue tape and CA glue” fixturing trick, which seemed to work quite well. For our money, though, the best bit is the lettering on the front face, which was milled out with an engraving bit and then filled with a spritz of white spray paint. A surfacing bit then came along to knock the overspray down, leaving labels that contrast beautifully with the dark wood. Gorgeous!

It wasn’t all easy sailing, though. There are just some things plastic can do that wood can’t, like holding screw threads in small studs without splitting. So, the case had to be glued shut once the mix of salvaged and new components went in. Still, it looks fabulous, and [Sebastian] says what we see in the video below is the one and only piece. Pretty sweet for the first try. Surprisingly, it doesn’t seem as if we’ve seen a wooden Game Boy before — a wooden NES, sure, but not a Game Boy.

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What The Artisan 3-in-1 CNC Offers (If One Has The Table Space)

November 1, 2023 by Donald Papp 34 Comments

I never feel like I have enough space in my workshop. The promise of consolidating tools to make the most of limited space drew me to the Snapmaker Artisan, a plus-sized 3-in-1 tool combining 3D printer, laser engraver, and CNC machine.

Smaller than three separate tools, but still big.

Jacks of all trades may be masters of none, but it is also true that a tool does not need to be a master of its functions to be useful. For many jobs, it enough to simply be serviceable. Does a machine like the Artisan offer something useful to a workshop?

Snapmaker was kind enough to send me an Artisan that I have by now spent a fair bit of time with. While I have come to expect the occasional glitch, having access to multiple functions is great for prototyping and desktop manufacturing.

This is especially true when it allows doing a job in-house where one previously had to outsource, or simply go without. This combo machine does have something to offer, as long as one can give it generous table space in return.

What It Is

The Artisan is a large dual-extrusion 3D printer, CNC router, and diode-based laser engraver. To change functions, one physically swaps toolheads and beds. Very thankfully, there are quick-change fixtures for this.

Driving the Artisan is Snapmaker’s software Luban (GitHub respository). Named for the ancient Chinese master craftsman, it is responsible for job setup and control. For laser and CNC work, there are convenient built-in profiles for a variety of paper, plastic, leather, and wood products.

The unit is enclosed, nicely designed, and — while I have come to expect the occasional glitch — serviceable at all three of its functions. The size and stature of the machine warrants some special mention, however.

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Simple Add-On Makes Cheap Plasma Cutter Suitable For CNC Use

September 30, 2023 by Dan Maloney 15 Comments

Plasma cutters are ridiculously cheap these days, just cruise by the usual online sources or your local Harbor Freight if you’ve got any doubt about that. But “cheap” and “good” don’t always intersect on a Venn diagram, and even when they do, not every plasma cutter is suitable for use on the spanking new CNC table you’re building. But luckily, there’s a mod for that.

As [Jake von Slatt] explains it, there are two kinds of plasma cutters on the market: high-frequency (HF) start and pilot arc start. The basic difference is that HF start cutters, which comprise the majority of cheap cutters on the market, need direct electrical contact with the workpiece to start the cutting action. Pilot arc torches, which are more suitable for CNC cutters, can strike the arc through a separate conductor without the need to contact the workpiece.

While there are homebrew bodges that claim to turn an HF torch into a pilot arc, [Jake]’s approach is a bit more complicated, and necessarily so. His add-on box intercepts the ground clamp — which is actually the positive conductor for plasma cutting — and switches it through a heavy-duty HVAC contactor. The 24 VDC coil of the contactor is controlled by a homebrew current sensor made from a huge toroid ferrite core wrapped with 20 turns of 6 AWG welding wire.

Before winding, the core is split in two and epoxied back together with a small magnetic reed switch bridging the gap. A simple 24 VDC power supply runs the whole thing. When the torch starts, the nozzle is connected to ground through the contactor, but as soon as the arc strikes and starts pulling cutting current through that toroid, the magnetic field closes the reed switch, which opens the contactor via a small DC relay. This removes the connection between the nozzle and ground, leaving the plasma to carry all the cutting current.

We’ve featured many, many CNC plasma cutter tables before, but most of these builds have concentrated on the table more than the cutter. It’s a refreshing change to get some insider tips on what kinds of cutters work best, and how to adapt what you’ve got for the job.

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String Art Build Uses CNC To Make Stringy Art

September 27, 2023 by Richard Baguley 12 Comments

String art is as old as, well, string and something to hang it from. But, like most things, it gets more enjoyable when you involve a CNC. [Paul MH] went the whole hog with this build, creating a CNC string art builder that could handle the whole process, from placing the nails to running the string.

It’s an impressive build: you feed in an image, and the system calculates the location of the pins and the path that the string will need to follow. It then puts the nails into the board, pushes them in, and, with a custom attachment for the CNC, runs the string to create the art.

Of course, the path to this was filled with prototypes, failures, and dead ends. [Paul] has laid these out pretty well in the video for the project, which he just released. In this, problems like detecting when the nails are picked up and placed are detailed, and the prototypes and Rube Goldberg solutions that [Paul] came up with are covered.

Like all great projects, it is still a work in progress, but [Paul] has made some impressive progress, although he hasn’t posted the code and models for his custom parts yet. We’ve featured several string art builds, from polar platforms to fully formed commercial-grade builds that print your work for you.

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Making An Injection Mold For Yourself

August 28, 2023 by Jenny List 29 Comments

Injection molding is the obvious onward step from 3D printing when the making of a few plastic parts becomes their series manufacture. The problem with injection molding is though, that making a mold can be prohibitively expensive. Has the advent of affordable CNC machining changed that? [Teaching Tech] takes a look, and machines a mold for part of a bicycle bracket.

With a diversion into home-made silicone seals for the injection molding machine, he proceeds to machine the mold itself from a block of aluminium. It’s a basic introduction to mold construction for those of us who’ve never ventured in this direction before, and it provides some interesting lessons. As we’d expect he does a rough machining pass before returning with a ball-end tool to smooth off those curves, but there’s a lesson in measuring rather than believing the paperwork. The tool he used was a bit smaller then the spec, so his path left some rough edges that had to be returned to. Otherwise the use of a removable pair of bolts to form holes in the finished part is we guess obvious after watching the video, but it’s something we learned as injection molding newbies.

This video follows on from a previous one we also covered, in which we’re introduced to the machine itself.

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Impulse Buying A 3040 CNC Machine, What Could Go Wrong?

August 26, 2023 by Donald Papp 46 Comments

[joekutz] made an impulse purchase of a CNC machine. It was a 3040 CNC that looked reasonably complete and had an attractive price, what could possibly go wrong? As it happens, [joekutz] really didn’t know what he was in for. Sometimes the price is good, but you pay in other ways. But where some would see defeat, [joekutz] sees an opportunity to document the restoration.

Dial indicators are useful tools for measuring how straight some parts aren’t.

The 3040 are relatively cheap and simple CNC machines that have been available from a variety of overseas retailers for years. They have 30 cm by 40 cm beds (hence the name) and while there are many variations, they all work about the same. [joekutz] expected that getting his up and running and converted to open source would be a fun weekend project, but it ended up taking far longer than that. In fact, it turns out that the machine was damaged in surprising and unexpected ways.

[joekutz] has a series of videos demonstrating the process of diagnosing and repairing the various things wrong with this device. In the first video, he dismantles the machine and discusses the next steps. In the second video, he takes some time to repair some dial indicators that will be critical for measuring the various things wrong with the CNC parts. Video number three delves into finding out the horrible things wrong with the machine, and the fourth is where repairs begin, including bending shafts and sanding blocks back into service.

Those videos are embedded below, and while the machine isn’t quite restored yet, progress is promising. We’ve seen easy and effective upgrades for such CNC machines before, but if you happen to be in more of a repair and restore situation, give [joekutz]’s work a look because it might just save you some time and frustration.

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Pen Plotter Uses Polar Coordinates

August 23, 2023 by Bryan Cockfield 12 Comments

To keep track of a location in a two-dimensional space, two measurements are needed. Most of the time, we would naturally think to do this by the Cartesian method, measuring position along one axis and then again along a second axis. But this isn’t the only way of keeping track of position. Polar coordinates, where the distance from the origin and an angle are used as the two measurements, works just as well, and sometimes can be a preferred method. This pen plotter tosses the expected Cartesian methodology we would typically expect in favor of this polar system.

The first prototype that [André] built was a good proof of concept. A pen attached to a movable carriage on a single rotating arm produced passable drawings, but as all prototypes go this one needed some refinement. Limit switches at the ends of the table, as well as within the arm, served to orient the plotter so that it didn’t manually need to be zeroed out every time. A linear actuator was added to give finer control over the pen’s pressure on the table, and finally an encoder was added to the base of the plotter to more accurately correct positional errors in the rotating arm mechanism.

With everything said and done, the polar coordinate plotter seems to work just as well as its Cartesian cousins might, orienting it like this has some advantages as well. Specifically, it is more adapted to drawing curves or circles than an X-Y device might be able to, like we saw with this similar sand-drawing plotter. Also, if allowed to rotate its entire 360-degree reach instead of just the 90 degrees shown in the video, a machine like this could theoretically reach a wider workspace more easily than other plotters.

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