Vintage Logan Lathe Gets 3D Printed Gears

January 13, 2018 by 34 Comments

In December 2016, [Bruno M.] was lucky enough to score a 70+ year old Logan 825 lathe for free from Craigslist. But as you might expect for a piece of machinery older than 95% of the people reading this page, it wasn’t in the best of condition. He’s made plenty of progress so far, and recently started tackling some broken gears in the machine’s transmission. There’s only one problem: the broken gears have a retail price of about $80 USD each. Ouch.

On his blog, [Bruno] documents his attempts at replacing these expensive gears with 3D printed versions, which so far looks very promising. He notes that usually 3D printed gears wouldn’t survive in this sort of application, but the gears in question are actually in a relatively low-stress portion of the transmission. He does mention that he’s still considering repairing the broken gears by filling the gaps left by the missing teeth and filing new ones in, but the 3D printed gears should at least buy him some time.

As it turns out, there’s a plugin available for Fusion 360 that helpfully does all the work of creating gears for you. You just need to enter in basic details like the number of teeth, diametral pitch, pressure angle, thickness, etc. He loaded up the generated STL in Cura, and ran off a test gear on his delta printer.

Of course, it didn’t work. Desktop 3D printing is still a finicky endeavour, and [Bruno] found with a pair of digital calipers that the printed gear was about 10% larger than the desired dimensions. It would have been interesting to find out if the issue was something in the printer (such as over-extrusion) or in the Fusion 360 plugin. In any event, a quick tweak to the slicer scale factor was all it took to get a workable gear printed on the third try.

This isn’t the first time we’ve seen 3D printed gears stand in for more suitable replacement parts, nor the first time we’ve seen them in situations that would appear beyond their capability. As 3D printer hardware and software improves, it seems fewer and fewer of the old caveats apply.

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Easy Time-lapse Video Via Phone And Command Line

January 13, 2018 by 6 Comments

A good time-lapse video can be useful visual documentation, and since [Tommy]’s phone is the best camera he owns he created two simple shell scripts to grab time-lapse images and assemble them into a video. [Tommy]’s work is just the glue between two other things: an app that turns the phone into an IP camera with a web server on the local network, and the ability to grab a still image from that server on demand.

The app he uses for his iPhone normally serves video but has an undocumented feature that allows single frames to be downloaded by adding ‘/photo’ to the end of the URL, but the ability to get a still image is a common feature on IP camera apps for smartphones. His capture script (GitHub repository here) should therefore need only minor changes to work with just about any IP camera app.

Perching a phone over a workspace and using it to create a time-lapse with a couple of shell scripts is a great example of combining simple tools to get better functionality. It could be a good way to get additional use out of an older smartphone, too. Heck, even older dumbphones can still get some use out of them; Shmoocon 2017 brought us details on rolling your own 1G network.

LED Stand For Lego Saturn V Boldly Goes Where No Lego Has Gone Before

January 13, 2018 by 10 Comments

Hackers everywhere have spent the last couple of weeks building the remarkable Saturn V Lego models that they got for the holidays, but [Kat & Asa Miller] decided to go an extra step for realism: they built a stand with LED lights to simulate launch. To get the real feel of blast off, they used pillow stuffing, a clear acrylic tube and a string of NeoPixel LEDs. These are driven by an Adafruit Trinket running code that [Asa] wrote to create the look of a majestic Saturn V just lifting off the launchpad with the appropriate fire and fury.  They initially were not sure if the diminutive Trinket would have the oomph to drive the LEDs, but it seems to work fine, judging by the video that you can see after the break.

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3D Print A Home Automation Switch

January 13, 2018 by 15 Comments

If you are the kind of person who won’t use cheap Sonoff modules to control AC powered devices, we don’t blame you and you should probably stop reading now. However, if you don’t mind a little exposed AC wiring and you have a 3D printer, you might be interested in the second generation of [530 Project’s] in-wall light switch.

The 3D printed switch fits a standard box and uses the guts of a Sonoff controller. These work with all the popular ecosystems such as Alexa and Google Home. And they are cheap. Like, really cheap. If you already have a 3D printer, even counting the cost of the filament these are going to be a small fraction of the cost of a commercial switch. You can see a video about the device, below.

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Inexpensive Display Jumps To Life

January 13, 2018 by 19 Comments

If you’ve ever been to a local fair or amusement park, chances are you’ve seen an illusion known as Pepper’s Ghost. To perform the illusion, essentially all that’s needed is a thin sheet of plastic or one-way mirror and a light source. Get it right, and you’ll have apparitions popping up in all kinds of interesting places. With just the right software, though, one of those places could be in your own 3D display.

Using just a tablet and a sheet of plastic rolled into a cone, a three-person team was able to create a 3D display using the Pepper’s Ghost illusion. Using special software that the team developed, an image is altered so that when it reflects off of the plastic cone the image appears as a 3D rendering of the original picture. The rendering is perspective-correct and offers a novel way to interact with a 3D model without needing expensive equipment or special glasses.

If you do have some fancy equipment sitting around, like a computer monitor and some plexiglass, similar 3D displays have been made which utilize similar effects. Right now the team that developed this one haven’t made their code open yet, but have promised to release it soon so that others can build their own displays.

Thanks to [bmsleight] for the tip!

Home Decorating With Tiny Arcade Cabinets

January 12, 2018 by 19 Comments

Thanks to the general miniaturization of electronics, the wide availability of cheap color LCD screens, and the fact that licensing decades old arcade games is something of a free-for-all, we can now purchase miniature clones of classic arcade cabinets for about $20 USD. In theory you could play these things, but given they’re less than 4 inches in height they end up being more of a desk novelty than anything. Especially since it seems like most of the effort went into making the cabinet itself; a classic example of “form over function”.

Unfortunately, if you want to buy these little arcade cabinets to use as decoration for your office or game room, they aren’t particularly well suited to the task. The “demo” mode where the game plays itself doesn’t last for very long, and even if it did, the game would chew through batteries at an alarming rate. [Travis] decided to tackle both issues head on by powering his Tiny Arcades over USB and locking them into demo mode.

The stock power for the Tiny Arcade comes from three AAA batteries, or 4.5 V. This made it easy enough to run over  5 V USB, and a four port USB charger is used to provide power to multiple machines at once. Forcing the game to stay in demo mode wasn’t much harder: a 555 timer was used to “push” the demo button with a frequency of every 10 seconds or so to keep the game up and running. A simple timer circuit was put together in the classic “dead bug” style, and sealed up with liquid rubber so it would play nice with the insides of the Tiny Arcade.

Since his little machines wouldn’t need their stock power switches anymore, [Travis] rewired the speaker lead through it. So now the machine stays on and in demo mode as long as it’s plugged into USB power, and you can flip the switch on the back to turn off the sounds. Perfect for sitting up on a shelf or the corner of your desk.

Usability issues not withstanding, there’s a pretty big (no pun intended) following for micro sized arcade cabinets. We’ve seen projects ranging from modding a Game Boy Advance to even tinier scratch builds.

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Warhammer 40K Model Rocket Launcher

January 12, 2018 by 5 Comments

[Daniel L]’s friend has a passion for Warhammer 40K. [Daniel] himself has a similar zeal for perfection in details. When he remembered a long-forgotten request to build a working rocket launcher for one of his friend’s Warhammer 40K models — well — the result was inevitably awesome.

The MicroMaxx motors — one of the smallest commercial rocket motors on the market — he had on hand seemed to fit the model of the Hyperios Whirlwind anti-air rocket tank. Modeling and 3D printing all the parts proved to be easier than assembling the incredibly detailed model — on top of sanding and filling gaps, a perfect paint job was no simple matter.

The launcher has two main circuit boards: a STM32F407 microcontroller brain, a low-power A20737A Bluetooth module, and a voltage regulator. The second has the constant current source and MOSFET output stages for the rocket igniters. Pitch and yaw handled by a pair of RC servo motors. [Daniel L] has also gone the extra mile by creating an accompanying iPhone app using the Anaren Atmosphere IDE — it’s simple but it works!

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