Laser Cutters: Where’s The Point?

It is funny how when you first start doing something, you have so many misconceptions that you have to discard. When you look back on it, it always seems like you should have known better. That was the case when I first got a low-end laser cutter. When you want to cut or engrave something, it has to be in just the right spot. It is like hanging a picture. You can get really close, but if it is off just a little bit, people will notice.

The big commercial units I’ve been around all had cameras that were in a fixed position and were calibrated. So the software didn’t show you a representation of the bed. It showed you the bed. The real bed plus whatever was on it. Getting things lined up was simply a matter of dragging everything around until it looked right on the screen.

Today, some cheap laser cutters have cameras, and you can probably add one to those that don’t. But you still don’t need it. My Ourtur Laser Master 3 has nothing fancy, and while I didn’t always tackle it the best way, my current method works well enough. In addition, I recently got a chance to try an XTool S1. It isn’t that cheap, but it doesn’t have a camera. Interestingly, though, there are two different ways of laying things out that also work. However, you can still do it the old-fashioned way, too. Continue reading “Laser Cutters: Where’s The Point?”

Proxxon CNC Conversion Makes A Small Mill A Bit Bigger

The Proxxon MF70 mini-mill is a cheap and cheerful, but decently made little desktop mill. As such, it’s been the target of innumerable CNC-ification projects, including an official kit from the manufacturer. But that didn’t stop [Dheera Venkatraman] from sharing his Big Yellow take on this venerable pursuit with us!

This isn’t simply a CNC modification, it’s a wholly 3D-printed CNC modification, which means that you don’t already need a mill to make the usual aluminum pieces to upgrade your mill. And perhaps the standout feature: [Dheera]’s mod basically doubles the Y-axis travel and adds an extra 15 mm of headroom to the Z. If you wanted to stop here, you would have a bigger small manual mill, but as long as you’re at it, you should probably bolt on the steppers and go CNC. It’s your call, because both models are included.

[Dheera] also built a nice enclosure for the MF70, which makes sense because it’s small enough that it could fit on your desktop, and you don’t want it flinging brass chips all over your bench. But as long as it’s on your desk, why not consider a soundproof enclosure for the MF70? Or take the next step, make a nice wooden box, mount a monitor in it, and take the MF70 entirely portable, like this gonzo hack from way back in 2012.

A person putting a screw into a CNC spoil board on the left of the image. Their drill is chartreuse and black. Clamps hold a rectangular board down at all four corners. The spindle of the CNC is just visible on the right hand side of the image.

Workholding Options For The Beginner CNC Operator

Designing a file to cut on a CNC is only part of the process. You also have to keep it in place while the machine does its work. [Garrett Fromme] walks us through five different work holding techniques.

Since every project is different and stock material can vary from thin veneer to much larger pieces, there’s no one right work holding method for every project, and not all methods are applicable to all materials. A vise is great for small projects that need to be held very securely and won’t be damaged, vacuum tables can make switching pieces quick in a production environment, fasteners will hold a piece securely at the expense of your spoil board, clamps are fairly versatile but fiddly to setup, and tape and CA glue are quick but require more consumables.

[Fromme] does a quick demonstration of setups with these different methods and their limitations, which is a great place to start for the beginner CNC operator. Just like 3D printers, CNCs are a far cry from the replicators in Star Trek that can automagically create what you ask it to, but proper workholding lets you waste less material and operate the machine more safely.

Our own [Elliot Williams] had a look at how CNCs aren’t as automated as you think. If you do need some CNC clamps, you might try these printable parametric clamps, or if you want something more beautiful, give these metal toe clamps a go.

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A LEGO CNC Pixel Art Generator

If you are ever lucky enough to make the trip to Billund in Denmark, home of LEGO, you can have your portrait taken and rendered in the plastic bricks as pixel art. Having seen that on our travels we were especially interested to watch [Creative Mindstorms]’ video doing something very similar using an entirely LEGO-built machine but taking the images from an AI image generator.

The basic operation of the machine is akin to that of a pick-and-place machine, and despite the relatively large size of a small LEGO square it still has to place at a surprisingly high resolution. This it achieves through the use of a LEGO lead screw for the Y axis and a rack and pinon for the X axis, each driven by a single motor.

The Z axis in this machine simply has to pick up and release a piece, something solved with a little ingenuity, while the magazine of “pixels” was adapted with lower friction from another maker’s design. The software is all written in Python, and takes input from end stop switches to position the machine.

We like this build, and we can appreciate the quantity of work that must have gone into it. If you’re a LEGO fan and can manage the trip to Billund, there’s plenty of other LEGO goodness to see there.

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The Cheap CNC3018 Gets A Proper Revamp

Many people have been attracted to the low price and big dreams of the CNC3018 desktop CNC router. If you’re quick, you can pick one up on the usual second-hand sales sites with little wear and tear for a steal. They’re not perfect machines by any stretch of the imagination, but they can be improved upon, and undoubtedly useful so long as you keep your expectations realistic.

[ForOurGood] has set about such an improvement process and documented their journey in a whopping eight-part (so far!) video series. The video linked below is the most recent in the series and is dedicated to creating a brushless spindle motor on a budget.

As you would expect from such a machine, you get exactly what you pay for.  The low cost translates to thinner than ideal metal plates, aluminium where steel would be better, lower-duty linear rails, and wimpy lead screws. The spindle also suffers from cost-cutting, as does the size of the stepper motors. But for the price, all is forgiven. The fact that they can even turn a profit on these machines shows the manufacturing prowess of the Chinese factories.

We covered the CNC 3018 a while back, and the comments of that post are a true gold mine for those wanting to try desktop CNC. Warning, though: It’s a fair bit harder to master than 3D printing!

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Betta Aims To Bring Wire EDM To The Desktop

Just as practical nuclear fusion has been “only 20 years away” for the last 80 years or so, the promise of electrical discharge machining (EDM) in the home shop seems to always be just around the corner. It’s hard to understand why this is so — EDM is electrically and mechanically more complicated than traditional subtractive manufacturing techniques, so a plug-and-play EDM setup seems always just out of reach.

Or perhaps not, if this 3D printed 4-axis wire EDM machine catches on. It comes to us from [John] at Rack Robotics and is built around the Powercore EDM power supply that we’ve previously featured. Since wire EDM is a process that requires the workpiece to be completely immersed in a dielectric solution, the machine, dubbed “Betta,” is designed to fit inside a 10-gallon aquarium — get it?

A lot of thought went into keeping costs down. for example, rather than use expensive sealed motors, [John] engineered the double CoreXY platform to keep the motors out of the water bath using long drive shafts and sealed bearings. The wire handling mechanism is also quite simple, at least compared to commercial WEDM machines, and uses standard brass EDM wire. The video below shows the machine going to town of everything from aluminum to steel, with fantastic results on thin or thick stock.

While Rack Robotics is going to be offering complete kits, they’re also planning on open-sourcing all the build files. We’re eager to see where this leads, and if people will latch onto EDM with the same gusto they did with 3D printing.

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Mostly Printed CNC Gets A Few Upgrades

The Mostly Printed CNC is famous for two things. First, being made mostly from 3D printed parts and commonly available steel tubing. Second, because of the materials used, its rigidity isn’t fantastic. But any CNC router is better than no CNC router, and [Alan Reiner]’s “Mostly Mostly Printed CNC” upgrades the base MPCNC into a much more capable unit.

MPCNC purists may want to look away, as the video below shows [Alan] committing the heresy of adding linear rails to his machine. The rails were sourced from VEVOR and at less than $100 for 10 meters, it must have been hard to resist. The rigidity wasn’t amazing — witness the horrific chatter at around the 5:15 mark — but [Alan] sorted that out with some aluminum extrusion and printed adapters.

Those upgrades alone were enough to let [Alan] dive into some aluminum cutting, but he also wanted to address another gripe with his base build: the Z-axis backlash. The fix there was to add another lead screw nut on an adjustable carrier. By tweaking the relative angles of the two opposed nuts, almost all of the backlash was taken up. [Alan] also replaced the motor coupling on the Z axis with a Lovejoy-style coupler, to remove as much axial compliance as possible.

Along with the motion control mods, [Alan] improved work holding and added an enclosure to tame the chip beast, along with some upgrades to the control electronics. The results are pretty good and appear well worth the modest added expense. Maybe a wireless controller can be next on the upgrade list?

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