When it comes to mechanical timepieces, we’re used to seeing mechanisms stuffed with tiny gears and wheel, often of marvelous complexity and precision. What we’re perhaps less used to seeing is a clock that uses chains and sprockets, and that looks more like what you’d find on a bicycle on your typical bicycle.
We can’t recall seeing anything quite like [SPE]’s “Time Machine” before. It’s one of those builds that explains itself by watching it work, so check out the video below and you’ll see where this one is going. The clock has three loops of roller link chain, each of which has a series of numbers welded to the links. The loops of chain are advanced around sprockets by a trio of geared-down motors, with the numbers standing up straight at the top of each loop. A microcontroller keeps track of the time and starts the clock advancing every minute, but a series of microswitches that are activated by the passing chain do all the rest of the control — sounds like a perfect time to say, “Could have used a 555,” but we still think it’s great the way it is.
Surprisingly, [SPE]’s clock seems like it wouldn’t be that hard to live with. Many unique electromechanical clocks that we feature, like a clock that’s nothing but hands or The Time Twister, are a little on the noisy side. While “Time Machine” isn’t exactly silent, its whirring isn’t terrible, and even though its clicks are a little loud, they’ve got a satisfying mechanical sound to them.
Continue reading “Sprockets And Chains Drive This Unique Mechanical Digital Clock”
It goes without saying that we love to see all the clever ways people have come up with to populate their printed circuit boards, especially the automated solutions. The idea of manually picking and placing nearly-microscopic components is reason enough to add a pick and place to the shop, but that usually leaves the problem of feeding components to the imagination of the user. And this mass-production-ready passive component feeder is a great example of that kind of imagination.
Almost every design we’ve seen for homebrew PnP component feeders have one of two things in common: they’re 3D-printed, or they’re somewhat complex. Not that those are bad things, but they do raise issues. Printing enough feeders for even a moderately large project would take forever, and the more motors and sensors a feeder has, the greater the chance of a breakdown. [dining-philosopher] solved both these problems with a simple design using only two parts, which can be resin cast. A lever arm is depressed by a plunger that’s attached to the LitePlacer tool, offset just enough so that the suction cup is lined up with the component location on the tape. A pawl in the lower arm moves forward when the tool leaves after picking up the part, engaging with the tape sprocket holes and advancing to the next component.
[dining-philosopher] didn’t attack the cover film peeling problem in his version, choosing to peel it off manually and use a weight to keep it taut and expose the next component. But in a nice example of collaboration, [Jed Smith] added an automatic film peeler to the original design. It complicates things a bit, but the peeler is powered by the advancing tape, so it’s probably worth it.
Continue reading “Printable, Castable Feeders Simplify Pick-and-Place Component Management”
Chain sprockets are a key drivetrain component in a lot of builds. Unfortunately they can be difficult to source, particularly for those outside the reach of retailers like McMaster-Carr. In such situations, you might consider making your own.
The toothed profile on a chain sprocket can be produced in a simple manner by drawing a base circle, along with a series of circles spaced appropriately for the chain in question. This involves measuring the pitch and roller diameter of the chain. With these measurements in hand, a template can be created to produce the sprocket.
From there a series of holes are drilled to rough out the basic shape of the teeth, before the sprocket is then cut down to its appropriate outer diameter. The finishing work consists of chamfering the sprocket’s thickness, as well as the filing the sharp edges of the teeth for smooth engagement.
It’s a quick and easy method for producing sprockets with well-defined, accurate profiles. We’ve featured other rough and ready methods before, too. Video after the break.
Continue reading “Making Your Own Chain Sprockets, The Tidy Way”
Sometimes, mechanical parts can be supremely expensive, or totally unavailable. In those cases, there’s just one option — make it yourself. It was this very situation in which I found myself. My electric scooter had been ever so slightly bested by a faster competitor, and I needed redemption. A gearing change would do the trick, but alas, the chain sprocket I needed simply did not exist from the usual online classifieds.
Thus, I grabbed the only tools I had, busied myself with my task. This is a build that should be replicable by anyone comfortable using a printer, power drill, and rotary tool. Let’s get to work!
Continue reading “How To Make An Electric Scooter Chain Sprocket With Nothing But Hand Tools”
When your widgets have proven so successful that building them gets to be a grind, it might be time to consider a little mechanical help in the form of a pick and place machine (PnP). If you’re going to roll your own though, there’s a lot to think about, not the least of which is how to feed your beast with parts.
Managing the appetite of a PnP is the idea behind this custom modular parts feeder, but the interesting part of [Hans Jørgen Grimstad]’s work-in-progress project has more to do with the design process. The feeders are to support a custom PnP being built in parallel, and so the needs of one dictate the specs of the other. Chief among the specs are the usual big three: cheap, fast, and reliable. But size is an issue too insofar that the PnP could be working with dozens of component reels at once. Flexibility was another design criteria, so that reels of varied width can be accommodated.
With all that in mind, [Hans] and company came up with a pretty slick design. The frame of the feeder is made out of the PCBs that house the motors for handling the tape, and the ATmega168 that controls everything. Tapes are driven by a laser-cut sprocket driven by 3D-printed worm gears. The boards have fingers that mate up to the aluminum extrusion that the PnP will be built from, and at only a few millimeters wider than the tape, lots of feeders can be nestled together. The video below shows the feeder undergoing some tests.
Alas, this build isn’t quite done, so you’ll have to check back for the final schematics and PCB files if you want to build one for yourself. While you’re waiting, you might want to build your own pick and place.
Continue reading “Custom Parts Feeder Aims To Keep Pace With Pick And Place”