The ability to build a robot to take care of a tedious task for you is power indeed. For a few centuries, the task of helping determine one’s location fell to the sextant. Now, you can offload that task to this auto-sextant, courtesy of [Raz85].
To be clear, this robo-sextant doesn’t give you your exact location, but it does find and display the bearing and altitude of the most luminous object around and display them on the LCD — so, the sun and moon. A pair of cheap servos handle the horizontal and vertical movement, an Arduino Uno acts as the brains and nervous system, and a photoresistor acts as the all-seeing eye. Clever use of some cardboard allow [Raz85] to keep the photoresistor isolated from most all light except what the sextant is currently pointed at. Servos have a limited field of movement, so you might need to adjust [Raz85]’s code accordingly if you’re rebuilding this one yourself.
After taking three minutes to make its rounds of the sky, the Uno records the servos’ positions when fixed on the sun or moon, translating that data into usable coordinates. Don’t forget the best part, it runs on batteries making it convenient for all your wave-faring excursions!
Continue reading “Finding The Sun And Moon The New Old-Fashioned Way”
People who know about bearings go through a phase of bemusement with regards to fidget spinners. We say something like, “man, I got a whole box of bearings in the basement.” Then we go through a “OK, I’ll make one” phase and print one out of PLA.
[fishpepper] took that sentiment a step further. After being forced to print spinners for his kids, he got jealous and decided to make his own—but his spinner would be a version for engineers. [fishpepper]’s ginormous spinner consists of five bearings superglued inside each other, with the grease cleaned out of the insides to make them spin faster. The inner two sets are doubled up bearings, 6 mm x 17 mm x 6 mm and 17 mm x 30 mm x 7 mm. The middle bearing measures 30 mm x 55 mm x 13 mm, and the fourth bearing 55 mm x 90 mm x 18 mm.
If you want to stop here, it’s a good size, around two inches across. However, [fishpepper] took it a step further, adding a fifth bearing, a 90 mm x 140 mm x 24 mm monster weighing in at 1 kg by itself. The total weight comes to 1.588 kg with the 3D-printed hub included. If you want to make one yourself, check out [fishpepper’s] bearing-in-bearing spinner tutorial which guides you through the various steps.
Hackaday likes fidget spinners so much you’d think we were in 6th grade: we’ve published posts on the three-magnet spinner hack, a fidget-spinning robot, and teaching STEAM with fidget spinners.
Continue reading “Bearing-in-Bearing Fidget Spinner Taken to the Max”
Consider the humble ball bearing. Ubiquitous, useful, and presently annoying teachers the world over in the form of fidget spinners. One thing ball bearings aren’t is easily 3D printed. It’s hard to print a good sphere, but that doesn’t mean you can’t print your own slew bearings for fun and profit.
As [Christoph Laimer] explains, slew bearings consist of a series of cylindrical rollers alternately arranged at 90° angles around an inner and outer race, and are therefore more approachable to 3D printing. Slew bearings often find application in large, slowly rotating applications like crane platforms or the bearings between a wind turbine nacelle and tower. In the video below, [Christoph] walks us through his parametric design in Fusion 360; for those of us not well-versed in the app, it looks a little like magic. Thankfully he has provided both the CAD files and a selection of STLs for different size bearings.
[Christoph] is no stranger to complex 3D-printable designs, like his recent brushless DC motor or an older clock build. The clock is cool, but the bearings and motors really get us — we’ll need such designs to get to self-replicating machines.
Continue reading “Big Slew Bearings Can Be 3D Printed”
So you’ve just taken apart a hard drive, and you’re looking at all the pieces on your desktop. You’re somehow compelled to use them all in different projects. Why not pull out that very high quality bearing that keeps the platters spinning at high RPMs and build this simple anemometer with it? That’s what [Sergei Bezrukov] did, and it looks like a perfect el cheapo project.
The build is fairly low-tech and entirely sufficient. The cups are made from plastic containers that used to contain pantyhose. A Hall-effect sensor and a magnet take care of measuring the rotations, feeding its signal into a PIC that calculates the wind speed from the revolution rate. The rest of the housing is PVC, with some other miscellaneous parts found at the hardware store.
To calibrate the device, [Sergei] made a second hand-held unit that he could (presumably) drive around in a car to get a baseline wind speed, and then note down the revolution rate. Once you’ve got a good reference, holding the portable unit up to the permanent one transfers the calibration.
But the star of the show, that lets the anemometer spin effortlessly, is the sweet bearing that used to spin a hard-drive platter. If you haven’t played with one of these bearings before, you absolutely should. We just ran a post on taking apart a hard drive for its spare-parts goodness so you have no excuse. If you’re feeling goofy, you can mount one onto a board, step on it with the ball of your foot, and spin. They’re quality bearings, and you’ll be surprised how quickly you can spin as you pull your arms in.
Thank [Matt] for the tip!
The whining of the turbines in the 3D printed pneumatic rotary tool might make your teeth hurt. When [Axodus] tipped us off about it he mentioned it sounded like a 747 taking off. But we hear a dentist’s drill when watching the demo video.
[Richard Macfarlane] published his design if you want to try building one for yourself. But you will need to do some machining in addition to printing the enclosure and the pair of turbines. The shaft of the tool needs to fit the bearings precisely. It accepts a center blue spacer with a red turbine on either side. This assembly is encapsulated in the two-part threaded blue body which has a flange to friction fit with the shop vacuum hose. The business end of the machined shaft was designed and threaded to accept the collet from a Dremel or similar rotary tool.
We wonder how much work it would be to re-engineer this to act as a PCB drill press?
Continue reading “60,000 RPM vacuum powered rotary tool was 3D printed”
[Ben Krasnow’s] water vortex machine has been an exhibit in the lobby of the San Jose City Hall for quite some time now. Unfortuantely he recently had to perform some repair work on it due to the parts inside the water chamber rusting.
This is the same water vortex that we saw about a year ago. It uses a power drill to drive an impeller at the bottom of a water column to produce the vortex. That impeller was made from painted steel and after being submerged for eight months it began rusting, which discolored the water. [Ben’s] repair process, which you can watch after the break, replaces the shaft and the impeller. He reused a plastic PC cooling fan as the new impeller. The replacement shaft is stainless steel, as is all of the mounting hardware that will be in contact with water. But for us, the most interesting part of the repair is his explanation of the shaft gasket and bearings. Two thrust bearings and two radial bearings ensure that the shaft cannot move axially, which would cause a problem with the gasket. He had intended to swap out the oil seal for an all Teflon seal but the machined acrylic wasn’t conducive to the part swap. Instead, he replaced it with the same type of gasket, but bolstered the new one with some silicone to stave off corrosion.
Continue reading “Water vortex exhibit repair gives a look at the bearing and gasket design”
While we normally don’t make it a habit to feature Kickstarter projects, we couldn’t pass this one up. [Barton Dring] from BuildLog.net is putting together a project called MakerSlide that we’re sure will interest many of you out there.
Through his various CNC builds, he has found that one of the more expensive and frustrating components to obtain is a linear bearing system. He notes that commercial systems are expensive, and while an occasional eBay bargain can be found, it’s not the ideal way of going about things. He also points out that homebrew systems usually work after some tuning and adjustments, but can be time consuming to build.
He is proposing a v-groove bearing system, complete with wheels made from Delrin, as a standardized replacement for all of the aforementioned solutions. He anticipates selling the rails for about 10 cents per centimeter, putting the average cost of a 4 foot system around $20.
As a bonus, he is offering up free MakerSlide materials to anyone that sends him a “new, innovative or interesting open source design or basic idea that uses the material.” You would only have to pay shipping in order to get your new project off the ground.
Standardization is always good, and seeing this rail system go into production would definitely benefit the hacker community. Take a minute to check it out if you are so inclined.