bearing

32 Articles

Adding Two Axes Makes CNC Router More Than The Sum Of Its Parts

July 26, 2023 by 20 Comments

The problem with building automated systems is that it’s hard to look at any problem and not see it in terms of possible automation solutions. Come to think of it, that’s probably less of a bug and more of a feature, but it’s easy to go overboard and automate all the things, which quickly becomes counterproductive in terms of time and money.

If you’re clever, though, a tactical automation solution can increase your process efficiency without breaking the budget. That’s where [Christopher Helmke] seems to have landed with this two-axis add-on fixture for his CNC router. The rig is designed to solve the problem of the manual modification needed to turn off-the-shelf plastic crates into enclosures for his line of modular automation components, aspects of which we’ve featured before. The crates need holes drilled in them and cutouts created in their sides for displays and controls. It’s a job [Christopher] tackled before with a drill and a jigsaw, with predictable results.

To automate the job without going overboard, [Christopher] came up with a tilting turntable that fits under the bed of the CNC router and sticks through a hole in the spoil board. The turntable is a large, 3D printed herringbone gear driven by a stepper and pinion gear. A cheap bearing keeps costs down, while a quartet of planetary gears constrain the otherwise wobbly platform. The turntable also swivels 90 degrees on a herringbone sector gear; together, the setup adds pitch and roll axes to the machine that allow the spindle access to all five sides of the crates.

Was it worth the effort? Judging by the results in the video below, we’d say so, especially given the number of workpieces that [Christopher] has to process. Add in the budget-conscious construction that doesn’t sacrifice precision too much, and this one seems like a real automation win.

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What’s In A Slip Ring?

June 19, 2023 by 20 Comments

We know that when [Big Clive] puts up another video, the chances are we’re in for another fascinating look into a piece of tech on his bench. The latest is a slip ring assembly, and he gives it a teardown to reveal its secrets.

For most of us, the only place we encounter a slip ring is in some electric motors or alternators when it provides a connection via a conductive ring and a graphite brush from a fixed component to a rotating one. But they also appear as components in their own right wherever a rotating assembly needs an electrical contact, and it’s one of these that [Clive] has on his bench. It’s a compact unit with an impressive six conductors, and its manufacturer boldly claims that it’s good for mains voltages. We’re going with the verdict in the video below the break. That’s wishful thinking, given the size of the unit.

Inside is a rotor with six brass rings and a couple of decent little bearings, while the other half of the unit is a set of gold-plated spring contacts. There is extensive use of potting, and the verdict is that this is a surprisingly good quality component for the eBay price. We look forward to our community finding inventive uses for them. Having a ready-made unit sure beats making your own.

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Kino Wheels Gives You A Hand Learning Camera Operation

March 28, 2023 by 4 Comments

Have you ever watched a movie or a video and really noticed the quality of the camera work? If you have, chances are the camera operator wasn’t very skilled, since the whole point of the job is to not be noticed. And getting to that point requires a lot of practice, especially since the handwheel controls for professional cameras can be a little tricky to master.

Getting the hang of camera controls is the idea behind [Cadrage]’s Kino Wheels open-source handwheels. The business end of Kino Wheels is a pair of DIN 950 140mm spoked handwheels — because of course there’s a DIN standard for handwheels. The handwheels are supported by sturdy pillow block bearings and attached to 600 pulse/rev rotary encoders, which are read by an Arduino Mega 2560. The handwheels are mounted orthogonal to each other in a suitable enclosure; the Pelican-style case shown in the build instructions seems like a perfect choice, but it really could be just about anything.

To use Kino Wheels, [Cadrage] offers a free camera simulator for Windows. Connected over USB, the wheels control the pan and tilt axes of a simulated camera in an animated scene. The operator-in-training uses the wheels to keep the scene composed properly while following the action. A little bit of the simulation is shown in the brief video below, along with some of the build details.

While getting camera practice is the point of the project, that’s not to say Kino Wheels couldn’t be retasked. With a little work, these could be used to actually control at least a couple of axes of a motion control rig, or maybe even to play Quake.

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Feeling The Heat: Railway Defect Detection

March 28, 2023 by 29 Comments

On the technology spectrum, railroads would certainly seem to skew toward the brutally simplistic side of things. A couple of strips of steel, some wooden ties and gravel ballast to keep everything in place, some rolling stock with flanged wheels on fixed axles, and you’ve got the basics that have been moving freight and passengers since at least the 18th century.

But that basic simplicity belies the true complexity of a railway, where even just keep keeping the trains on the track can be a daunting task. The forces that a fully loaded train can exert on not only the tracks but on itself are hard to get your head around, and the potential for disaster is often only a failed component away. This became painfully evident with the recent Norfolk Southern derailment in East Palestine, Ohio, which resulted in a hazardous materials incident the likes of which no community is ready to deal with.

Given the forces involved, keeping trains on the straight and narrow is no mean feat, and railway designers have come up with a web of sensors and systems to help them with the task of keeping an eye on what’s going on with the rolling stock of a train. Let’s take a look at some of the interesting engineering behind these wayside defect detectors.

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Icicle Patterns With Custom Gantry

March 22, 2023 by 2 Comments

[Cranktown City] uses a number of custom-built linear rails used as gantries for various tools in the shop. The first is on a plasma cutter, which is precise but difficult to set up or repair. Another is for mounting a camera, and while it is extremely durable, it’s not the most precise tool in the shop. Hoping to bridge the gap between these two, he’s building another gantry with a custom bearing system, and to test it he’ll be using it to create patterns in icicles hanging from an eave at his shop.

While this isn’t the final destination for this gantry, it is an excellent test of it, having to perform well for a long period of time in an extremely cold environment. The bearing system consists of a piece of square steel tubing turned 45° inside another larger square steel tube and held in place with two sets of three bearings with V-shaped notches. To drive the gantry he is using a motor with a belt drive, and for this test a piece of drip irrigation is mounted to it which lets out a predetermined amount of water on top of the roof to create numerous icicles beneath with various programmed lengths.

After a few test runs the gantry system can create some icicles, although they don’t have the exact sine wave shape that [Cranktown City] programmed into it. They are varying lengths though, and with no more cold days in the forecast he’s called it a success. This isn’t the final destination for this robotic linear gantry, though, but it did help him work out some of the kinks with it beforehand. For other sources of inspiration, take a look at this linear rail system also used for driving various robotic tooling.

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Wire race bearing

Adding Wire Races Improves 3D-Printed Bearings

December 13, 2021 by 35 Comments

Like a lot of power transmission components, bearings have become far easier to source than they once were. It used to be hard to find exactly what you need, but now quality bearings are just a few clicks away. They’re not always cheap though, especially when you get to the larger sizes, so knowing how to print your own bearings can be a handy skill.

Of course, 3D-printed bearings aren’t going to work in every application, but [Eros Nicolau] has a plan for that. Rather than risk damage from frictional heating by running plastic or metal balls in a plastic race, he uses wire rings as wear surfaces. The first video below shows an early version of the bearing, where a pair of steel wire rings lines the 3D-printed inner and outer races. These worked OK, but suffered from occasional sticky spots and were a bit on the noisy side.

The second video shows version two, which uses the same wire-ring race arrangement but adds a printed ball cage to restrain the balls. This keeps things quieter and eliminates binding, making the bearing run smoother. [Eros] also added a bit of lube to the bearing, in the form of liquid PTFE, better known as Teflon. It certainly seemed to smooth things out. We’d imagine PTFE would be more compatible with most printed plastics than, say, petroleum-based greases, but we’d be keen to see how the bearings hold up in the long term.

Maybe you recall seeing big 3D-printed bearings around here before? You’d be right. And we’ve got you covered if you need to learn more about how bearings work — or lubricants, for that matter.

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Magnetic Bearings Put The Spin On This Flywheel Battery

July 22, 2021 by 35 Comments

[Tom Stanton] is right about one thing: flywheels make excellent playthings. Whether watching a spinning top that never seems to slow down, or feeling the weird forces a gyroscope exerts, spinning things are oddly satisfying. And putting a flywheel to work as a battery makes it even cooler.

Of course, using a flywheel to store energy isn’t even close to being a new concept. But the principles [Tom] demonstrates in the video below, including the advantages of magnetically levitated bearings, are pretty cool to see all in one place. The flywheel itself is just a heavy aluminum disc on a shaft, with a pair of bearings on each side made of stacks of neodymium magnets. An additional low-friction thrust bearing at the end of the shaft keeps the systems suitably constrained, and allows the flywheel to spin for twelve minutes or more.

[Tom]’s next step was to harness some of the flywheel’s angular momentum to make electricity. He built a pair of rotors carrying more magnets, with a stator of custom-wound coils sandwiched between. A full-wave bridge rectifier and a capacitor complete the circuit and allow the flywheel to power a bunch of LEDs or even a small motor. The whole thing is nicely built and looks like a fun desk toy.

This is far from [Tom]’s first flywheel rodeo; his last foray into storing mechanical energy wasn’t terribly successful, but he has succeeded in making flywheels fly, one way or another.

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