Mastering Ball Screws

November 2, 2016 by 32 Comments

Most inexpensive 3D printers use a type of lead screw to move some part of the printer in the vertical direction. A motor turns a threaded rod and that causes a nut to go up or down. The printer part rides on the nut. This works well, but it is slower than other drive mechanisms (which is why you don’t often see them on the horizontal parts of a printer). Some cheap printers use common threaded rod, which is convenient, but prone to bad behavior since the rods are not always straight, the threads are subject to backlash, and the tolerances are not always the best.

More sophisticated printers use ACME threaded rod or trapezoidal threaded rods. These are made for this type of service and have thread designs that minimize things like backlash. They typically are made to more exacting standards, too. Making the nut softer than the rod (for example, brass or Delrin) is another common optimization.

However, when lead screws aren’t good enough, mechanical designers turn to ball screws. In principle, these are very similar to lead screws but instead of a nut, there is a race containing ball bearings that moves up and down the screw. The ball bearings lead to less friction.

Misumi recently posted a few blog articles about ball screws. Some of the information is basic, but it also covers preloading and friction. Plus they are promising future articles to expand on the topic. If you prefer to watch a video, you might enjoy the one below.

Continue reading “Mastering Ball Screws” →

ESP32 Modules Popping Up Everywhere, In Stock Almost Nowhere

November 2, 2016 by 46 Comments

We know what it’s like to wait for newly released electronic parts. Clicking refresh every day at your favorite online retailers, reading reviews published by the press who got preview units, and maybe even daring to order implausibly cheap devices from foreign lands. The ESP32 has many of us playing the waiting game, and we’ll level with you — they’re out of stock most places. But, if you look hard enough you can find one. At least, you could find them before we wrote this quick roundup of ESP32 hardware. If hearing about parts that are just out of reach is your sort of thing, then read on, you masochist!

Continue reading “ESP32 Modules Popping Up Everywhere, In Stock Almost Nowhere” →

Rotary Cell Phone: Blast From A Past That Never Was

November 2, 2016 by 32 Comments

The 1970s called and they want their rotary dial cell phone back.

Looking for all the world like something assembled from the Radio Shack parts department – remember when Radio Shack sold parts? – [Mr_Volt]’s build is a celebration of the look and feel of a hobbyist build from way back when. Looking a little like a homebrew DynaTAC 8000X, the brushed aluminum and 3D-printed ABS case sports an unusual front panel feature – a working rotary dial. Smaller than even the Trimline phone’s rotating finger stop dial and best operated with a stylus, the dial translates rotary action to DTMF tones for the Feather FONA board inside. Far from a one-trick pony, the phone sports memory dialing, SMS messaging, and even an FM receiver. But most impressive and mysterious is the dial mechanism, visible through a window in the wood-grain back. Did [Mr_Volt] fabricate those gears and the governor? We’d love to hear the backstory on that.

This isn’t the first rotary cell phone hybrid we’ve featured, of course. There was this GSM addition to an old rotary phone and this cell phone that lets you slam the receiver down. But for our money a rotary dial cell phone built from the ground up wins the retro cool prize of the bunch.

Continue reading “Rotary Cell Phone: Blast From A Past That Never Was” →

LED Matrix Shades You Can Actually See Though

November 2, 2016 by 16 Comments

[Gal Pavlin] admits to enjoying the occasional dance music show. For those who have never been to one, LED one-upmanship at these shows is a real and terrible thing, so much so that an entire market exists around it. To that end, [Gal] built a pretty spiffy set of LED glasses.

It took quite a bit of work to arrive at the final design. All the circuitry and LEDs fit entirely within the envelope of the lenses on a pair of sunglass frames of dubious parentage. The batteries squeeze in between the user’s head and temples.

On top of the clever packaging is an equally impressive set of features. Each lens is a matrix of 69 LEDs. They have an accelerometer, a microphone, and a light sensor. There’s even a vibrating alert motor, which we feel is just showing off.  Best of all, you can actually see through the glasses, thanks to clever layout and very tiny LEDs.

The device requires a tag connect or soldering on a pigtail to program. If you’d like to build one yourself all the files are available on [Gavin]’s site. There’s a video of it in operation after the break.

Continue reading “LED Matrix Shades You Can Actually See Though” →

Easy Parabolic Mirror From A Trash Can Lid

November 1, 2016 by 34 Comments

Parabolic reflectors for solar applications are nice stuff, and making your own is a great project in itself. One of the easiest ways we have seen is that of [GREENPOWERSCIENCE], who uses nothing more than a trash can lid, mylar film, and tape. You need a way to make a partial vacuum though.

The idea is so simple that it´s almost like cheating. Cut a circle of mylar slightly larger than the lid, and tape it all around, taking care of stretching the mylar in the process. After you´re done with this, you end up with a nice flat mirror. Here´s where the vacuum is needed to force the film into parabolic shape. Extract the air from a little hole in the lid that was previously drilled, and tape it to prevent the loss of the vacuum. The atmospheric pressure on the mylar film will take care of the job, and magically you get a nearly-parabolic reflector ready for work.

In this other video, you can see the reflector in action burning stuff. One obvious problem with this technique is the loss of the vacuum after some time, about an hour according to the author. Here´s another way to make a more durable mirror also with mylar as the reflecting element, however the quality of the resulting mirror is not as good.

 

Surf’s Up! Virtually

November 1, 2016 by No comments

While it may or may not be true that if everybody had an ocean they’d be surfing like California, it is true that with a water pump, some copper tape, and a few scraps you can make a surfing simulator that sprays you if you don’t keep your balance.

You can see the simple device in operation in the video below. We presume [Adi_10] actually surfs, but we can’t comment on the realism of the simulator. There’s no computer. Just a switch made from the base and the balance board.

Continue reading “Surf’s Up! Virtually” →

Wii U RetroPie Console Looks Gorgeous

November 1, 2016 by 8 Comments

What to do with your broken gaming consoles? Gut it and turn it into a different gaming console! Sudomod forum user [banjokazooie] has concocted his own RetroPie console from the husk of a WiiU controller — an ingenious demonstration of how one can recycle hardware to a perfectly suited purpose.

[banjokazooie] actually used an original shell for this build, but if you happen to have a broken controller around — or know someone who does — this is a great use for it. A Raspberry Pi 3 is the brains of this operation (not counting [banjokazooie]), and it features a 6.5″ HDMI display, a Teensy 2.0 setup for the inputs, a headphone jack with automatic speaker disconnection, dual 3400 mAh batteries, an external SD card slot, and a lot of hard work on the power supply circuit — although [banjokazooie] reports that the hardest part was cutting to size a custom PCB to mount it all on. The original plan was to see if the idea was possible, and after a three month effort, it appears to work beautifully.

Continue reading “Wii U RetroPie Console Looks Gorgeous” →