CoreXY

24 Articles

Third Time’s A Charm For This Basketball-Catching Robot

September 9, 2020 by 20 Comments

We all know that version one of a project is usually a stinker, at least in retrospect. Sure, it gets the basic idea into concrete form, but all it really does is set the stage for a version two. That’s better, but still not quite there. Version three is where the magic all comes together.

At least that’s how things transpired on [Shane Wighton]’s quest to build the perfect basketball robot. His first version was a passive backboard that redirected incoming shots based on its paraboloid shape. As cool as the math was that determined the board’s shape, it conspicuously lacked any complicated systems like motors and machine vision — you know, the fun stuff.  Version two had all these elaborations and grabbed off-target shots a lot better, but still, it had a limited working envelope.

Enter version three, seen in action in the video below. Taking a page from [Mark Rober]’s playbook, [Shane] built a wickedly overengineered CoreXY-style robot to cover his shop wall. Everything was built with the lightest possible materials to keep inertia to a minimum and ensure the target ends up in the right place as quickly as possible. [Shane] even figured out how to mount the motor that tilts the backboard on the frame rather than to the carriage. A Kinect does depth-detection duty on the incoming ball — or the builder’s head — and drains pretty much every shot it can reach.

[Shane] has been doing some great work automating away the jobs of pro athletes. In addition to basketball, he has tackled both golf and baseball, bringing explosive power to each. We’re looking forward to versions two and three on both of those builds as well.

Continue reading “Third Time’s A Charm For This Basketball-Catching Robot” →

Moving Fridge Magnets Make For Unique Clock

August 14, 2020 by 40 Comments

We see a ton of clock projects around these parts, and being hackers, we love to feature them all. But every once in a while we stumble upon a great new way to display the time that really gets our attention and requires a closer look, such as this moving fridge magnet clock.

The fridge magnets [Craig Colvin] built this unique clock around are the colorful plastic kinds that have adorned the lower regions of refrigerators in toddler-filled households for ages. Instead of residing on a fridge, [Craig] laminated a sheet of white acrylic to a thin sheet of steel, to give the magnets something to hold onto. Moving the numbers is the job of a CoreXY-style mechanism. The belt-driven Cartesian movement maneuvers a head to to the right location to pick up a number; a servo in the head moves two powerful magnets into position under the number. The head then moves the number to the right spot, releases its magnets, and the number stays put on the board. You can see it in action in the video after the break.

While we love this as it is, it brings to mind some great mods. One can imagine the addition of letters to make a legit word clock, or to just add a calendar display. We’d also love to see these magnets in their natural habitat by building this into the door of a working fridge.

Continue reading “Moving Fridge Magnets Make For Unique Clock” →

Hackaday Podcast 045: Raspberry Pi Bug, Rapidly Aging Vodka, Raining On The Cloud, And This Wasn’t A Supercon Episode

December 6, 2019 by 5 Comments

Hackaday editors Mike Szczys and Elliot Williams talk over the last three weeks full of hacks. Our first “back to normal” podcast after Supercon turns out to still have a lot of Supercon references in it. We discuss Raspberry Pi 4’s HDMI interfering with its WiFi, learn the differences between CoreXY/Delta/Cartesian printers, sip on Whiskey aged in an ultrasonic jewelry cleaner, and set up cloud printing that’s already scheduled for the chopping block. Along the way, you’ll hear hints of what happened at Supercon, from the definitive guide to designing LEDs for iron-clad performance to the projects people hauled along with them.

Take a look at the links below if you want to follow along, and as always tell us what you think about this episode in the comments!

Take a look at the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!

Direct download (60 MB or so.)

Where to Follow Hackaday Podcast

Places to follow Hackaday podcasts:

Continue reading “Hackaday Podcast 045: Raspberry Pi Bug, Rapidly Aging Vodka, Raining On The Cloud, And This Wasn’t A Supercon Episode” →

Core XY Explained

November 12, 2019 by 28 Comments

If you are building a CNC machine, a 3D printer, or even a plotter, you have a need for motion in both the X and Y directions. There are many ways to accomplish this, for example, some printers move the tool in the X direction and the bed in the Y direction while others move the entire X carriage in the Y direction and yet more use a delta mechanism. However, one of the oldest means of doing this is the Core XY method. It is interesting because both motors remain stationary and the business end moves entirely on belts or cords. This is similar to the H-Bot technique, but with some differences. [Michael Laws] has a video (see below) that explains how two stationary motors can move a tool anywhere in an XY region.

The idea behind Core XY goes back to at least old drafting tables. You can think of it as an object held by two ends of the same belt. As one end of the belt gets shorter the other end gets longer. The belts are arranged so that motion of one motor causes the tool to move at a 45 degree angle. That means you have to move both motors to go in a straight line.

Continue reading “Core XY Explained” →

Watch A 3D Printer Get Designed From The Ground Up

November 10, 2019 by 15 Comments

Too often when you see a build video, you only get to see the final product. Even if there’s footage of the build itself, it’s usually only the highlights as a major component is completed. But thankfully that’s not the case with the “V-Baby” CoreXY 3D printer that [Roy Berntsen] has been working on.

Watching through his playlist of videos, you’re able to see him tackle his various design goals. For example he’d like the final design to be both machinable and printable, which is possible, but it certainly adds complexity and time. He also transitions from a triangular base to a rectangular one at some point. These decisions, and the reasons behind them, are all documented and discussed.

Towards the end of the series we can see the final testing and torturing process as he ramps up to a final design release. This should definitely demystify the process for anyone attempting their first 3D printer design from scratch.

The HackadayPrize2019 is Sponsored by:

X-Printer Fits In A Backpack

October 2, 2019 by 16 Comments

3D printers are great for rapid prototyping, but they’re not usually what you’d call… portable. For [Malte Schrader], that simply wouldn’t do – thus, the X-printer was born!

The X-printer is a fused-deposition printer built around a CoreXY design. Its party piece is its folding concertina-style Z-axis, which allows the printer to have a build volume of 160x220x150mm, while measuring just 300x330x105mm when folded. That’s small enough to fit in a backpack!

Getting the folding mechanism to work took some extra effort, with the non-linear Z-axis requiring special attention in the firmware. The printer runs Marlin 1, chosen for its faster compile time over Marlin 2. Other design choices are made with an eye to ruggedness. The aluminium frame isn’t as light as it could be, but adds much needed rigidity and strength. We’d love to see a custom case that you could slide the printer into so it would be protected while stowed.

It’s a build that shows there’s still plenty to be gained from homebrewing your own printer, even in the face of unprecedented options on the market today. We’ve seen other unique takes on the portable printer concept before, too. Video after the break.

Continue reading “X-Printer Fits In A Backpack” →

Classy CoreXY Build Breaks Down The Design Pinchpoints

August 3, 2018 by 5 Comments

Ever since [Ilan Moyer] published the design, CoreXYs have been exploding in the homebrew 3D Printer community. Nevertheless, not all designs are created equal, and a solid design means adhering to some unspoken constraints. Fear not, though. [Mark Rehorst’s] blog post pulls the lid off these constraints and puts them up-front-and-center.  For anyone looking to succeed with their own CoreXY build, this thoughtful critique will keep us away from stray design paths.

[Mark’s] blogpost centers around the xy-stage of his UMMD printer. Here, he walks through the constraints of where belts should be located to guarantee dimensional accuracy of parts. Engineering doesn’t always result in designing the parts ourselves, but rather picking them from a list of options. This geometry-constraint breakdown gives us a more acute set of eyes the next time we pick a CoreXY frame to download and clone off of a place like Thingiverse.

What’s more, for all the antagonizing forces acting on our xy-stage like thermal expansion and frame flexing, [Mark] comes in with a countermeasure. Belts are thickened. Moving stages are constrained correctly, and pulley blocks are reinforced for a stage that is both precise and accurate. Given that it’s so easy to get another printer to start producing parts, lessons learned here will guide us on what underlying measures they need to counteract for a successful print stage.

It’s hard not to love [Mark Rehorst’s] foray into at-home printer builds. Not only do we see new ideas that constantly reinvent how we design printers, each build comes bundled with a wealth of tips and drawbacks. [Mark] gives us a tested design and a critical set of eyes on it that better helps us explore the space if we so choose. For more thoughtful additions to your next 3D printer, check out [Mark’s] CPAP-style remote cooling fan and belt-driven z axis.