Inspire Dev Kit Drops Price Of MSLA Printer To Just $30

March 4, 2021 by Tom Nardi 41 Comments

Over the last couple of years, we’ve seen massive price reductions on consumer 3D printers based on masked stereolithography (MSLA) technology. As the name implies, these machines use a standard LCD panel to selectively mask off the ultraviolet light coming from an array of LEDs. Add in a motorized Z stage, and you’ve got a simple and cheap way of coaxing UV resin into three dimensional shapes. These days, $200 USD can get you a turn-key MSLA printer with resolution far beyond the capabilities of filament-based FDM machines.

But [JD] still thinks we can do better. His project aims to produce a fully-functional MSLA printer for $30, and perhaps as low as $15 if manufactured in sufficient quality. He believes that by making high-resolution 3D printing more accessible, it will allow users all over the globe to bring their ideas to life. It’s no wonder he’s calling his machine the Inspire 3D Printer.

This isn’t just some pie in the sky concept rolling around in [JD]’s head, either. You can order the Inspire Development Kit right now for just $30, though he makes it clear what you’ll receive isn’t quite a functional MSLA printer. By leveraging a common LCD module, the ESP32, and several 3D printed parts, he’s proven his price point for the kit is achievable; but there’s still plenty of work that needs to be done before the machine is ready for the general public.

For one thing, he’s still working the kinks out of the Z movement. The current design is 3D printed, but [JD] says he’s not quite happy with the amount of slop in the movement and is considering replacing the entire thing with the linear actuator from an optical drive. We’ve already seen these parts reused for accurately positioning lasers, so there’s certainly precedent for it. The firmware for the ESP32 is also in its infancy, and currently only allows the user to print from a selection of simple hard-coded shapes as a proof of concept.

We’ve seen DIY attempts at resin printers in the past, but they’ve often been based on more complex techniques involving projectors or UV lasers. Masked stereolithography is much more approachable for the home gamer, and projects like the Inspire 3D Printer show just how little it really takes to pull solid objects out of a puddle of goo.

Arduboy FX Mod-Chip: Now You’re Playing With Power

March 4, 2021 by Tom Nardi 13 Comments

Traditionally, a forum full of technical users trying integrate their own hardware into a game system for the purposes of gaining unfettered access to its entire software library was the kind of thing that would keep engineers at Sony and Nintendo up at night. The development and proliferation of so called “mod chips” were an existential threat to companies that made their money selling video games, and as such, sniffing out these console hackers and keeping their findings from going public for as long as possible was a top priority.

But the Arduboy is no traditional game system. Its games are distributed for free, so a chip that allows users to cram hundreds of them onto the handheld at once isn’t some shady attempt to pull a fast one on the developers, it’s a substantial usability improvement over the stock hardware. So when Arduboy creator Kevin Bates found out about the grassroots effort to expand the system’s internal storage on the official forums, he didn’t try to put a stop to it. Instead, he asked how he could help make it a reality for as many Arduboy owners as possible.

Now, a little less than three years after forum member Mr.Blinky posted his initial concept for hanging an external SPI flash chip on the system’s test pads, the official Arduboy FX Mod-Chip has arrived. Whether you go the DIY route and build your own version or buy the ready-to-go module, one thing is for sure: it’s a must-have upgrade for the Arduboy that will completely change how you use the diminutive handheld.

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2:3 Scale VT100 Is A Perfect Pairing For PDP-8/I Replica

March 4, 2021 by Tom Nardi 12 Comments

When he went shopping for a vintage serial terminal to go along with his reproduction PDP-8/I computer, [Michael Gardi] came down with a bad case of sticker shock. But rather than be discouraged, he reasoned that if his “retro” computer could stand to have modern components at its heart, so could the terminal he used to talk to it. Leaning on his considerable experience in designing 3D printed replica hardware, he’s built an absolutely gorgeous scaled down DEC VT100 terminal that any classic computer aficionado would be happy to have on their desk.

Now to be clear, [Michael] hasn’t created a true serial terminal. Since the faux PDP-8/I is running on a Raspberry Pi, all he needed to do was come up with something that could connect to its HDMI and USB ports. Put simply, he’s essentially just made a 3D printed enclosure for the Pi’s monitor and keyboard. Oh, but what a gorgeous enclosure it is.

Recreating the VT100 in CAD was made more difficult by the fact that [Michael] couldn’t get his hands on the authentic hardware. But of course, that’s never stopped him before. It turns out DEC provided some very detailed dimensions for the terminal in their original documentation, and while comparing them to photographs of the actual terminal did uncover a few key differences, the overall look is spot on. Once the design was done, he reports it took two rolls of filament and more than 200 hours to print out all the parts for the enclosure.

To help sell the authentic look [Michael] tracked down a 4:3 LCD of the appropriate size, and the use of an off-the-shelf portable mechanical keyboard should make text entry a pleasure. For a little fun, he even came up with a themed arcade controller for the VT100 that can be used with RetroPie. The printed logo plate is an especially nice touch, and we’re more than willing to forgive the fact that he had to print it at a larger scale than the rest of the terminal to get all the detail in with his printer’s 0.4 mm nozzle.

On a technical level, this is perhaps the most straightforward replica we’ve ever seen from [Michael]. But even on a relatively simple project like this, his signature attention to detail and craftsmanship is on full display. It’s always a good day when he’s got a new build to show off with, and we’re eager to see what he comes up with next.

Generator Runs On Natural Gas With Field Expedient Tip

March 3, 2021 by Tom Nardi 111 Comments

Many small gasoline engines can be safely modified to run on natural gas or propane with a kit that replaces the carburetor and adds a regulator, providing a reliable alternative fuel source in the event that gasoline is difficult to obtain in an emergency situation. This seat of the pants hack by [HowToLou] is definitively not the safe way to run your generator on natural gas, but if you ever find yourself in a situation where getting the power back on might be a literal matter of life or death, it’s a tip worth keeping in mind.

The basic idea here is that you feed natural gas (though propane should also work) directly into the engine’s intake by way of a hose attached to the air filter box. While cranking the engine, a valve on the gas line is used to manually adjust the air–fuel mixture until it fires up. It’s an extremely simple hack that, in a pinch, you can pull off with the parts on hand. But as you might expect, that simplicity comes at a cost.

There are a few big problems with this approach, but certainly the major one is that there’s nothing to cut off the flow of gas when the engine stops running. So if the generator stalls or you just forget to close the valve after you shut it down, there’s the potential for a very dangerous situation. Additionally, the manual gas valve will be at odds with a generator that automatically throttles up and down based on load. Though to be fair, there are certainly generators out there that simply run the engine flat-out the whole time.

Much like his DIY generator interlock plate that we covered last month, we imagine this project may rub some folks in the wrong way. Admittedly, this isn’t a modification that you should take lightly and certainly not something you’d want to rely on for long-term use. But as the recent situation in Texas has reminded us, drastic times can occasionally call for drastic measures.

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Attack Of The Flying 18650s

March 3, 2021 by Tom Nardi 31 Comments

When somebody builds a quadcopter with the express purpose of flying it as fast and aggressively as possible, it’s not exactly a surprise when they eventually run it into an immovable object hard enough to break something. In fact, it’s more like a rite of passage. Which is why many serious fliers will have a 3D printer at home to rapidly run off replacement parts.

Avid first person view (FPV) flier [David Cledon] has taken this concept to its ultimate extreme by designing a 3D printable quadcopter that’s little more than an 18650 cell with some motors attached. Since the two-piece frame can be produced on a standard desktop 3D printer in a little over two hours with less than $1 USD of filament, crashes promise to be far less stressful. Spend a few hours during the week printing out frames, and you’ll have plenty to destroy for the weekend.

While [David] says the overall performance of this diminutive quadcopter isn’t exactly stellar, we think the 10 minutes of flight time he’s reporting on a single 18650 battery is more than respectable. While there’s still considerable expense in the radio and video gear, this design looks like it could be an exceptionally affordable way to get into FPV flying.

Of course, the argument could be made that such a wispy quadcopter is more likely to be obliterated on impact than something larger and commercially produced. There’s also a decent amount of close-quarters soldering involved given the cramped nature of the frame. So while the total cost of building one of these birds might be appealing to the newbie, it’s probably a project best left to those who’ve clocked a few hours in on the sticks.

We’ve seen quite a few 3D printed quadcopter frames over the years, but certainly none as elegant as what [David] has created here. It’s an experiment in minimalism that really embraces the possibilities afforded by low-cost desktop 3D printing, and we wouldn’t be surprised to see it become the standard by which future designs are measured.

How To Design A Custom Generator Interlock Plate

February 22, 2021 by Tom Nardi 85 Comments

If you connect a generator to your home’s main electrical panel when the power goes out, you need to make sure the main breaker is shut off. Otherwise, when the power comes back on, you (or the linemen) are going to have a bad time. There are commercial interlock plates which physically prevent the generator and main breakers from being switched on at the same time, but since they tend to be expensive, [HowToLou] decided to make one himself.

The hardest part of this project is designing the template. It needs to be carefully shaped so its resting position prevents the generator’s breaker from being switched on under normal circumstances, but once the main is turned off and out of the way, you should be able to lift it up and have the clearance to flip the lower breaker. Spending some quality time at the breaker box with tape and a few pieces of cardboard is going to be the easiest way of finding the proper shape.

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Slick Web Oscilloscope Is Ready In A Flash (Literally)

February 22, 2021 by Tom Nardi 27 Comments

A bench oscilloscope is one of the most invaluable tools in the hardware hacker’s arsenal, but even the slimmest digital models are a bit large to be part of your everyday electronic carry. Sure you could throw one of those cheap pocket scopes in your bag, but what if there was an even easier way to take a peek at a few signals while you’re on the go?

For those who roam, the Arduino-web-oscilloscope project created by [David Buezas] is worth a close look. Using the Web Serial API built into recent versions of Google’s Chrome browser, this project allows you to pop open a software oscilloscope without installing anything locally. Whether it’s a public computer or that cheap Chromebook you keep around for emergencies, a valuable tool is just a few clicks away.

Flashing the MCU from the web interface.

Of course, there has to be some hardware involved. Despite what you might think given the name of the project, the code currently only supports the Logic Green LGT8F328P microcontroller. This cheap ATmega328P clone not only runs at 32 Mhz but according to [David], many operations can be done in fewer clock cycles than on the original 328P. In short it’s fast, and fast is good if you want more samples.

One of the best parts about this project is that a function to flash the firmware to the LGT8F328P is built right in the web interface. With the oscilloscope running in the browser, you just need to plug in a blank board, click the button to flash it, and start taking measurements. You could outfit a whole classroom or hackerspace with basic oscilloscopes in minutes, with a per-seat cost of just a few bucks.

Now as you might expect, there are some pretty hard limits on what you can realistically measure with this setup. For one thing, the board can’t handle anything higher than 5 volts. Even the cheapest oscilloscope kit is still going to be an upgrade, but the fact you can spin this up almost anywhere for the cost of a cheap MCU board makes it hard to complain about the results.

[Thanks to Bill for the tip.]