PCB Holder Quick-fix Turns Out To Be Big Improvement

July 1, 2018 by Donald Papp 15 Comments

When something needs improving, most hacks often make a small tweak to address a problem without changing how things really work. Other hacks go a level deeper, and that’s what [Felix Rusu] did with his 3D printed magnetic holders. Originally designed to address a shortcoming with the PCB holders in his LE40V desktop pick-and-place machine, they turned out to be useful for other applications as well, and easily modified to use whatever size magnets happen to be handy.

The problem [Felix] had with the PCB holders on his pick-and-place was that they hold the board suspended in midair by gripping the sides. The board is held securely, but the high density of parts on panelized PCB designs leads to vibrations in the suspended board as the pick-and-place head goes to work. Things are even worse when the board is v-scored for the purpose of easily snapping apart the smaller boards later; they sometimes break along the score lines due to the stress.

Most people would solve this problem by putting a spacer underneath the board to stabilize things, but [Felix] decided to go a level deeper and change the mounting system altogether with a simple mod. The boards now lie on a flat metal plate, and his magnetic holders are simple to make and easily do the job of holding any size PCB secure. As a bonus, it turns out that the holders also do a passable job of holding work materials down on a laser cutter’s honeycomb table. A video overview is embedded below, and the design files are available on Thingiverse.

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Handmade Robot Brings Stop Motion To Life

June 29, 2018 by Tom Nardi 17 Comments

Stop motion animation is often called a lost art, as doing it (or at least, doing it well) is incredibly difficult and time consuming. Every detail on the screen, no matter how minute, has to be placed by human hands hundreds of times so that it looks smooth when played back at normal speed. The unique look of stop motion is desirable enough that it still does get produced, but it’s far less common than hand drawn or even computer animation.

If you ever wanted to know just how much work goes into producing even a few minutes of stop motion animation, look no farther than the fascinating work of [Special Krio]. He not only documented the incredible attention to detail required to produce high quality animation with this method, but also the creation of his custom robotic character.

Characters in stop motion animation often have multiple interchangeable heads to enable switching between different expressions. But with his robotic character, [Special Krio] only has to worry about the environments, and allow his mechanized star do the “acting”. This saves time, which can be used for things such as making 45 individual resin “drops” to animate pouring a cup of tea (seriously, go look).

To build his character, [Special Krio] first modeled her out of terracotta to get the exact look he wanted. He then used a DIY 3D laser scanner to create a digital model, which in turn he used to help design internal structures and components which he 3D printed on an Ultimaker. The terracotta original was used once again when it was time to make molds for the character’s skin, which was done with RTV rubber. Then it was just the small matter of painting all the details and making her clothes. All told, the few minutes of video after the break took years to produce.

This isn’t the first time we’ve seen 3D printing used to create stop motion animation, but the final product here is really in a league of its own.

[Thanks to Antonio for the tip.]

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3D Printed Tourniquets Are Not A Cinch

June 28, 2018 by Brian McEvoy 32 Comments

Saying that something is a cinch is a way of saying that it is easy. Modeling a thin handle with a hole through the middle seems like it would be a simple task accomplishable in a single afternoon and that includes the time to print a copy or two. We are here to tell you that is only the first task when making tourniquets for gunshot victims. Content warning: there are real pictures of severe trauma. Below, is a video of a training session with the tourniquets in Hayat Center in Gaza and has a simulated wound on a mannequin.

On the first pass, many things are done correctly: the handle is the correct length and diameter, the strap hole fit the strap, and the part is well oriented on the platen. As with many first iterations, it looks good on a screen, but in the real world, we all live under Murphy’s law. In practice, some of the strap holes had sharp edges that cut into the strap, and one of the printed buckles broke unexpectedly.

On the whole, the low cost and availability of the open-source tourniquets outweigh the danger of operating without them. Open-source medical devices are not just for use in the field, they can help with training too. This tourniquet is saving people and proving that modeling skills can be a big help in the real world.
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Tiny Printers Get Color Mixing

June 28, 2018 by Brian Benchoff 8 Comments

Last weekend was the inaugural East Coast RepRap Festival in beautiful Bel Air, Maryland. Like it’s related con, the Midwest RepRap Festival, ERRF is held in the middle of nowhere, surrounded by farms, and is filled with only people who want to be there. It is the anti-Maker Faire; only the people who have cool stuff to show off, awesome prints, and the latest technology come to these RepRap Fests. This was the first ERRF, and we’re looking forward to next year, where it will surely be bigger and better.

One of the stand-out presenters at ERRF didn’t have a big printer. It didn’t have normal stepper motors. There weren’t Benchies or Marvins or whatever the standard test print is these days. [James] is showing off tiny printers. Half-scale printers. What’s half the size of a NEMA 17 stepper motor? A NEMA 8, apparently, something that isn’t actually a NEMA spec, and the two companies that make NEMA 8s have different bolt hole patterns. This is fun.

If these printers look familiar, you’re right. A few years ago at the New York Maker Faire, we checked out these tiny little printers, and they do, surprisingly, print. There are a lot of tricks to make a half-size printer, but the most impressive by far is the tiny control board. This tiny little board is just 2.5 by 1.5 inches — much smaller than the standard RAMPS or RAMBO you’d expect on a DIY printer. On the board are five stepper drivers, support for two heaters, headers for OLEDs and Graphic LCDs, and a switching regulator. It’s a feat of microelectronics that’s impressive and necessary for a half-size printer.

Since we last saw these tiny printers, [James] has been hard at work expanding what is possible with tiny printers. The most impressive feat from this year’s ERRF was a color-mixing printer built around the same electronics as the tiny printers. The setup uses normal-size stepper motors (can’t blame him) and a diamond-style hotend to theoretically print in three colors. If you’ve ever wanted a tiny printer, this is how you do it, and I assure you, they’re very, very cute.

Pool Ball Return System Chalked Up To Ingenuity

June 27, 2018 by Kristina Panos 12 Comments

Do you play pool? If so, you probably take the automatic ball return systems in bar and billiard hall tables for granted. [Roger Makes] was tired of walking around his home table to collect the balls every time he wanted to play, so he designed a time-saving ball return system.

Instead of falling into the little netted baskets that came with the table, the balls now drop into 3D-printed pockets and ride along dowel rod rails into a central collection box, which is suspended by straps beneath the rack-em-up end of the table. The rails themselves are fortified with ABS ribs that keep the balls from falling through.

Pool is all about geometry, and this really hit home when [Roger] was trying to merge the funnel part of the pocket with the exit chute in the design phase. He covered all the angles with a modular design that lets the chute rotate freely, which takes a lot of stress away from the dowel rods. We’ve got the video cued up after the break, so don’t bother with getting out your film canister full of quarters.

We can’t wait to see what [Roger Makes] next. Maybe it’ll be something like this OpenCV score-keeping system.

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Apple Coin Bank Plants The Seed Of Saving

June 25, 2018 by Kristina Panos 14 Comments

Consider the piggy bank. Behind that innocent, docile expression is a capitalistic metaphor waiting to ruin your fond memories of saving for that BMX bike or whatever else it was that drove home the value of a dollar. As fun as it is to drop a coin in a slot, the act of saving your pennies and learning financial responsibility could be a bit more engaging.

It seems like [gzumwalt] feels the same way. He’s designed a coin bank for his grand-kids that takes a more active role in the deposit process—it straight up eats the things. Put a coin on the platform and the upper half of the apple’s face is pushed open by an arm that pulls the coin inside on its return path.

Continuing with the money-saving theme, [gzumwalt] didn’t use a micro or even a 555. No, the core of this project is a pair of micro lever switches, a small gear motor, and 4.5V DC. When a coin hits the platform, the first switch engages the motor. The motor drives a 3-D printed mechanism modeled after Hoeckens’ linkage, which converts rotational motion to (nearly) straight-line motion. The second switch stops the cycle. Confused? You can sink your teeth into it after the break.

Don’t worry, the kids don’t have to slice up the apple when it’s time to go to the candy store, ’cause there’s a screw-in hatch on the bottom. This is because [gzumwalt] is a wizard of 3-D printing and design. Not convinced? Check out his balloon-powered engine or his runs-on-air plane.

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Lost In Space Gets 3D Printing Right

June 25, 2018 by Tom Nardi 100 Comments

When it has become so common for movies and television to hyper-sensationalize engineering, and to just plain get things wrong, here’s a breath of fresh air. There’s a Sci-Fi show out right now that wove 3D printing into the story line in a way that is correct, unforced, and a fitting complement to that fictional world.

With the amount of original content Netflix is pumping out anymore, you may have missed the fact that they’ve recently released a reboot of the classic Lost in Space series from the 1960’s. Sorry LeBlanc fans, this new take on the space traveling Robinson family pretends the 1998 movie never happened, as have most people. It follows the family from their days on Earth until they get properly lost in space as the title would indicate, and is probably most notable for the exceptional art direction and special effects work that’s closer to Interstellar than the campy effects of yesteryear.

But fear not, Dear Reader. This is not a review of the show. To that end, I’ll come right out and say that Lost in Space is overall a rather mediocre show. It’s certainly gorgeous, but the story lines and dialog are like something out of a fan film. It’s overly drawn out, and in the end doesn’t progress the overarching story nearly as much as you’d expect. The robot is pretty sick, though.

No, this article is not about the show as a whole. It’s about one very specific element of the show that was so well done I’m still thinking about it a month later: its use of 3D printing. In Lost in Space, the 3D printer aboard the Jupiter 2 is almost a character itself. Nearly every member of the main cast has some kind of interaction with it, and it’s directly involved in several major plot developments during the season’s rather brisk ten episode run.

I’ve never seen a show or movie that not only featured 3D printing as such a major theme, but that also did it so well. It’s perhaps the most realistic portrayal of 3D printing to date, but it’s also a plausible depiction of what 3D printing could look like in the relatively near future. It’s not perfect by any means, but I’d be exceptionally interested to hear if anyone can point out anything better.

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