Aluminum No Match For 3D Printed Press Brake Dies

January 14, 2018 by Tom Nardi 44 Comments

If you’re looking for a get-rich-quick scheme, you can scratch “Doing small-scale manufacturing of ultralight aircraft” off your list right now. Turns out there’s no money in it. At least, not enough money that you can outsource production of all the parts. Not even enough to setup a huge shop full of customized machining tools when you realize you have to make the stuff yourself. No, this sounds like one of those “labors of love” we always hear so much about.

So how does one do in-house manufacturing of aircraft with a bare minimum of tools? Well, since you’re reading this on Hackaday you can probably guess that you’ve got to come up with something a bit unorthodox. When [Brian Carpenter] of Rainbow Aviation needed a very specific die to bend a component for their aircraft, he decided to try designing and 3D printing one himself.

He reasoned that since he had made quick and dirty dies out of wood in the past, that a 3D printed one should work for at least a few bends before falling apart. He even planned to use JB Weld to fill in the parts of the printed die which he assumed would start cracking and breaking off after he put it through a few cycles. But even after bending hundreds of parts, wear on the dies appears to be nearly non-existent. As an added bonus, the printed plastic dies don’t mar the aluminum pieces they are bending like the steel dies do.

So what’s the secret to printing a die that can bend hundreds of pieces of aluminum on a 20 ton brake without wearing down? As it turns out…not a whole lot. [Brian] attributes the success of this experiment to designing the die with sufficiently accurate tolerances and having so high of an infill that it may as well be solid plastic.

In fact, the 3D printed die worked out so well that they’ve now expanded the idea to a cheap Harbor Freight brake. Before this tool was going more or less unused as it didn’t have features they needed for the production of their parts, namely a radius die or backstop. But by 3D printing these components [Brian] was able to put the tool back to work.

We’ve previously covered the art and science of bending sheet metal, as well as a homebuilt brake that let’s you do it on a budget even Rainbow Aviation would scoff at. So what are you waiting for? Go build an airplane.

Thanks to [Oahupilot] for the tip.

Continue reading “Aluminum No Match For 3D Printed Press Brake Dies” →

Not So Simple LED Upgrade For Microscope

January 14, 2018 by Donald Papp 18 Comments

[Amen] obtained a microscope whose light source was an incandescent bulb, but the light from it seemed awfully dim even at its brightest setting. Rather than hunt down a replacement, he decided to replace the bulb with a 1W LED mounted on a metal cylinder. The retrofit was successful, but there were numerous constraints on his work that complicated things. The original bulb and the LED replacement differed not just in shape and size, but also in electrical requirements. The bulb was also part of an assembly that used a two-pronged plug off to the side for power. In the end, [Amen] used 3D printing, a bit of metal work, and a bridge rectifier on some stripboard to successfully replace his microscope’s incandescent bulb assembly with an LED. He even used a lathe to make connector pins that mated properly with the microscope’s proprietary power connector, so that the LED unit could be a drop-in module.

Working on existing equipment always puts constraints on one’s work, usually due to space limitations, but sometimes also proprietary signals. For example, a common issue when refitting a projector with an LED is to discover that the projector expects a stock bulb, and refuses to boot up without one. Happily, the microscope didn’t care much about the bulb itself, and with the LED positioned in roughly the same position as the original bulb’s filament [Amen] obtained smooth and even lighting across the field of view with no changes made to the microscope itself.

Vintage Logan Lathe Gets 3D Printed Gears

January 13, 2018 by Tom Nardi 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.

Continue reading “Vintage Logan Lathe Gets 3D Printed Gears” →

Rolling Robot With Two Motors, But None Are On The Wheels

January 12, 2018 by Donald Papp 4 Comments

This unusual 3D printed Rolling Robot by [ebaera] uses two tiny hobby servos for locomotion in an unexpected way. The motors drive the front wheel only indirectly, by moving two articulated arms in a reach-and-retract motion similar to a breaststroke. The arms are joined together at the front, where a ratcheting wheel rests underneath. When the arms extend, the wheel rolls forward freely. When the arms retract, the wheel’s ratchet locks and the rest of the body is pulled forward. It looks as though extending one arm more than the other provides for rudimentary steering.

The parts are all 3D printed but some of them look as though they might be a challenge to print well due to the number of small pieces and overhangs. A short video (embedded below) demonstrates how it all works together; the action starts about 25 seconds in.

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Printed PC Speakers Are Way Cooler Than Yours

January 12, 2018 by Tom Nardi 21 Comments

On the off chance you’re reading these words on an actual desktop computer (rather than a phone, tablet, smart mirror, game console…), stop and look at the speakers you have on either side of your monitor. Are you back now? OK, now look at the PC speakers and amplifier [Kris Slyka] recently built and realize you’ve been bested. Don’t feel bad, she’s got us beat as well.

The speaker and amplifier enclosures were painstakingly printed and assembled over the course of three months, and each piece was designed to be small enough to fit onto the roughly 4 in x 4 in bed of her PrintrBot Play. While limited print volume made the design considerably trickier, it did force [Kris] to adopt a modular design approach with arguably made assembly (and potential future repairs or improvements) easier.

The amplifier is made up of rectangular “cells” which are connected to each other via 3 mm threaded rods. For now the amplifier only has 4 cells, but this could easily be expanded in the future without having to design and print a whole new case. Internally the amplifier is using two TDA8932 digital amplifier modules, and some VU meters scored off of eBay.

Each speaker enclosure is made up of 10 individual printed parts that are then glued and screwed together to make the final shape, which [Kris] mentions was inspired by an audio installation at the Los Angeles County Museum of Art. They house 4″ Visaton FR 10 HM drivers, and are stuffed with insulation.

It’s a bit difficult to nail down the style that [Kris] has gone for here. You see the chunky controls and analog VU meters and want to call it retro, but it’s also a brass cog and sprocket away from being Steampunk. On the other hand, the shape of the speakers combined with the bamboo-filled PLA used to print them almost gives it an organic look: as if there’s a tree somewhere that grows these things. That’s actually a kind of terrifying thought, but you get the idea.

If your computer speakers were assembled by mere mortals, never fear. We’ve covered a number of interesting hacks and mods for more run-of-the-mill desktop audio setups which should hold you over until it’s time to harvest the speaker trees.

[via /r/3Dprinting]

When A Skimmer Isn’t A Skimmer

January 2, 2018 by Tom Nardi 163 Comments

I have a confession to make: ever since the first time I read about them online, I’ve been desperate to find an ATM skimmer in the wild. It’s the same kind of morbid curiosity that keeps us from turning away from a car accident, you don’t want to be witness to anyone getting hurt, but there’s still that desire to see the potential for danger up close. While admittedly my interest is largely selfish (I already know on which shelf I would display it), there would still be tangible benefits to the community should an ATM skimmer cross my path. Obviously I would remove it from the machine and prevent others from falling prey to it, and the inevitable teardown would make interesting content for the good readers of Hackaday. It’s a win for everyone, surely fate should be on my side in this quest.

So when my fingers brushed against that unmistakable knobby feel of 3D printed plastic as I went to insert my card at a local ATM, my heart skipped a beat. After all these years, my dream had come true. Nobody should ever be so excited about potentially being a victim of fraud, but there I was, grinning like an idiot in the farmer’s market. Like any hunter I quickly snapped a picture of my quarry for posterity, and then attempted to free it from the host machine.

But things did not go as expected. I spend most of my free time writing blog posts for Hackaday, so it’s safe to say that physical strength is not an attribute I possess in great quantity, but even still it seemed odd I couldn’t get the skimmer detached. I yanked it in every direction, tried to spin it, did everything short of kicking it; but absolutely no movement. In fact, I noticed that when pulling on the skimmer the whole face plate of the ATM bulged out a bit. I realized this thing wasn’t just glued onto the machine, it must have actually been installed inside of it.

I was heartbroken to leave my prize behind, but at the very least I would be able to alert the responsible party. The contact info for the ATM’s owner was written on the machine, so I emailed them the picture as well as all the relevant information in hopes that they could come check the machine out before anyone got ripped off.

Continue reading “When A Skimmer Isn’t A Skimmer” →

Electronics Workbench Goes Vertical With Pegboard Mounting

January 1, 2018 by Donald Papp 8 Comments

[JesusGomez] has certainly put work into his Vertical Laboratory concept. There’s a bit more to the idea than simply using 3D printed parts to move electronics from the desktop onto a metal pegboard, although that part is certainly nicely done. There are 3D models for securely mounting various hardware such as Raspberry Pi, Beaglebone, ESP32, cable management, breadboards, and other common parts to a metal pegboard. Instead of having parts and wires splayed across a workbench, it can be mounted and organized vertically. Having a project or prototype mounted on pegboard is easier to store, saves room, and frees up desk space in small work areas. It also makes for an organized and visually pleasing layout.

A clever piece of design is in the plastic mounts that he created. He wanted parts to remain securely mounted unless intentionally removed, allow different mounting orientations, and to never require access to the back side of the pegboard. To accomplish this, the parts use a combination of pegs that slide-lock with bendable sections that act as lock tabs. Once mounted, the parts stay put until the lock tabs are released by gently prying them out of position. Since mounting and removal can be done entirely from the front, wall mounted pegboards with inaccessible backs can be used.

Metal pegboard has its uses, even if the more common dead-tree version shows up more often in projects from DIY vacuforming to making a modular work surface for when space is at an absolute premium.