Making A Motorized Turntable Portable

[Robin Reiter] needed a better way to show off his work. He previously converted an electric TV stand into a full 360-degree display turntable, but it relied on an external power supply to get it spinning. It was time to give it an upgrade.

Putting his spacial organization skills to work, [Reiter] has crammed a mini OLED display, rotary encoder, a LiPo 18650 battery and charging circuit, a pair of buck converters, a power switch, and an Arduino pro mini into the small control console. To further maximize space, [Reiter] stripped out the pin headers and wired the components together directly. It attaches to the turntable in question with magnets, so it can be removed out of frame, or for displaying larger objects!

When first powered on, the turntable holds in pause mode giving [Reiter] time to adjust the speed and direction. He also took the time to add an optical rotary encoder disk to the turntable and give the gearing a much needed cleaning. Check out the project video after the break!

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Rubies Are A 3D Printer’s Best Friend

Watching a 3D printer work always reminds us of watching a baker decorate a cake. Gooey icing squeezes out of a nozzle and makes interesting shapes and designs. While hot plastic doesn’t taste as good as icing, it does flow easily through the printer’s nozzle. Well… normal plastic, anyway. These days, advanced 3D printers are using filament with wood, metal, carbon fiber, and other additives. These can provide impressive results, but the bits of hard material in them tend to wear down metallic nozzles. If this is your problem and you are tired of replacing nozzles, you should check out the Olsson Ruby Nozzle.

Ruby, in this case, isn’t just a name. The nozzle has a small bit of ruby with a 0.4mm hole in the center — or they have a few other sizes. We suppose diamond would even be better, but ruby is so much more affordable. We haven’t tried these ourselves, but [3D Printing Nerd] has an interesting video review you can see below.

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Peer Review In The Age Of Viral Video

Recently, a YouTube video has been making the rounds online which shows a rather astounding comparison between two printed models of the US Capitol. Starting with the line “3-D PRINTERS CAN NOW PRINT TWICE AS FAST”, the video shows that one print took four hours to complete, and the other finished in just two hours by virtue of vibration reducing algorithms developed at the University of Michigan. The excitement around this video is understandable; one of the biggest limitations of current 3D printer technology is how long it takes to produce a model of acceptable quality, and if improvements to the software that drives these machines could cut total print time in half, the ramifications would be immense.

In only a few weeks the video racked up tens of thousands of views, and glowing articles popped up with headlines such as: “How to cut 3D print times in half by the University of Michigan” and “University of Michigan professor doubles 3D printing speeds using vibration-mitigating algorithm“. Predictably, our tips line lit up with 3D printer owners who wanted to hear more about the incredible research that promised to double their print speed with nothing more than a firmware update.

The only problem is, the video shows nothing of the sort. What’s more, when pushed for details, the creators of the video are now claiming the same thing.

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Entry-Level 3D Printer Becomes Budget PCB Machine

A funny thing happened on [Marco Rep]’s way to upgrading his 3D printer. Instead of ending up with a heated bed, his $300 3D printer can now etch 0.2-mm PCB traces. And the results are pretty impressive, all the more so since so little effort and expense were involved.

The printer in question is a Cetus3D, one of the newer generation of affordable machines. The printer has nice linear bearings but not a lot of other amenities, hence [Marco]’s desire to add a heated bed. But hiding beneath the covers was a suspicious transistor wired to a spare connector on the print head; a little sleuthing and a call to the factory revealed that the pin is intended for accessory use and can be controlled from G-code. With a few mods to the cheap UV laser module [Marco] had on hand, a printed holder for the laser, and a somewhat manual software toolchain, PCBs with 0.2-mm traces were soon being etched. The video below shows that the printer isn’t perfect for the job; despite the smooth linear bearings, the low mass of the printer results in vibration that shows up as wavy traces. But the results are more than acceptable, especially for $330.

This isn’t [Marco]’s first budget laser-etching rodeo. He recently tried the same thing using a cheap CNC laser engraver with similar results. That was a $200 dedicated engraver, this is a $300 3D printer with a $30 laser. It seems hard to lose at prices like these.

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Acetone Smoothing Results In Working Motor

Here’s something only ’90s kids will remember. In 1998, the Air Hogs Sky Shark, a free-flying model airplane powered by compressed air was released. This plane featured foam stabilizers, wings, a molded fuselage that served as a reservoir, and a novel engine powered by compressed air. The complete Sky Shark setup included an air pump. All you had to do was plug the plane into the pump, try to break the pressure gauge, and let the plane fly off into a tree or a neighbor’s rooftop. It’s still a relatively interesting mechanism, and although we’re not going to see compressed air drones anytime soon it’s still a cool toy.

Since [Tom Stanton] is working at the intersection of small-scale aeronautics and 3D printing, he thought he would take a swing at building his own 3D printed air motor. This is an interesting challenge — the engine needs to be air-tight, and it needs to produce some sort of usable power. Is a standard printer up to the task? Somewhat surprisingly, yes.

The design of [Tom]’s motor is more or less the same as what is found in the Air Hogs motor from twenty years ago. A piston is attached to a crank, which is attached to a flywheel, in this case a propeller. Above the cylinder, a ball valve keeps the air from rushing in. A spring is mounted to the top of the piston which pushes the ball out of the way, allowing air into the cylinder. At the bottom of the stroke, the ball closes the valve and air escapes out of the bottom of the cylinder. Simple stuff, really, but can it be printed?

Instead of the usual printer [Tom] uses for his builds, he pulled out an old delta slightly modified for higher quality prints. Really, this is just a 0.2 mm nozzle and a few tweaks to the print settings, but the air motor [Tom] designed came out pretty well and was smoothed to a fine finish with acetone.

After assembling the motor, [Tom] hooked it up to a soda bottle serving as a compressed air reservoir. The motor worked, although it’s doubtful a plane powered with this motor would fly for very long. You can check out [Tom]’s video below.

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3D Printed Cookie Molds For The Best Speculoos

Experiencing nostalgia for the outstanding Belgian cuisine [Adam], currently stuck in Ohio, found himself in craving some home-made speculoos. For the uninitiated, speculoos is what those brown cookies usually served with coffee on planes dream of becoming one day.

To add some extra regional flavour, [Adam] decided to print his own molds featuring motifs from Brussels. The risks of 3D prints in the kitchen are the subject of a lively discussion. They are addressed in this project by recommending the use of food safe filament and sealant for the molds. The fact that the dough will be removed from the molds almost instantly and that the molds don’t go into the oven puts the risks in the vicinity of using plastic cutting boards in your kitchen.

[Adam]’s write up features solid, well illustrated baking instructions that should enable any of you to replicate this delicacy. Some links to additional references and two recipes are thrown in for good measure. The article finishes with detailed instructions for designing your own molds that take the properties of the medium into account, to ensure your custom motif will still be recognizable after baking. Line art with a stroke width of around 2-3 mm seems to work best. It is that time of year and we hope to see a lot more tricks to take your cookie and edible house designs to the next level so don’t forget to send in a tip.

With 3D printed molds having been used to shape resin, silicone and even metal, we are at a point where cookie dough looks like a natural progression.

Visual 3D Print Finishing Guide

With 3D printers now dropping to record low prices, more and more people are getting on the additive manufacturing bandwagon. As a long time believer in consumer-level desktop 3D printing, this is a very exciting time for me; the creativity coming out of places like Thingiverse or the 3D printing communities on Reddit is absolutely incredible. But the realist in me knows that despite what slick promotional material from the manufacturers may lead you to believe, these aren’t Star Trek-level replicators. What comes out of these machines is often riddled with imperfections (from small to soul crushing), and can require considerable cleanup work before they start to look like finished pieces.

If all you hope to get out of your 3D printer are some decent toy boats and some low-poly Pokemon, then have no fear. Even the most finicky of cheap printers can pump those out all day. But if you’re looking to build display pieces, cosplay props, or even prototypes that are worth showing to investors, you’ve got some work cut out for you.

With time, patience, and a few commercial products, you can accomplish the ultimate goal: turning a 3D printed object into something that doesn’t look like it was 3D printed. For the purposes of this demonstration I’ll be creating a replica of the mobile emitter used by the “Emergency Medical Hologram” in Star Trek: Voyager. I can neither confirm nor deny I selected this example due to the fact that I’m currently re-watching Voyager on Netflix. Let’s make it look good.

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