Small Footprint Scara Laser Engraver Has Massive Build Area

August 31, 2021 by Danie Conradie 22 Comments

One of the limitations of the conventional Cartesian CNC platforms is that the working area will usually be smaller than its footprint. SCARA arms are one of the options to get around this, as demonstrated by [How To Mechatronics], with his SCARA laser engraver.

This robot arm is modified from the original build we featured a while back, which had a gripper mounted. It uses mainly standard 3D printer components with 3D printed frame parts. The arms lengths are sized to fold over the base and take up little table horizontal space when not in use. It can work in a large semi-circular area around itself, and if a proper locating and homing method is implemented, it can be moved around and engrave a large area section by section.

One of the challenges of SCARA arms is rigidity. As the cantilevered arm extends, it tends to lean over under its weight. In [How To Mechatronics]’s case, it showed up as skewed engravings, which he managed to mitigate to some degree in the Marlin firmware.

Another possible solution is to reduce the weight of the arms by moving the motors to the base, as was done with the Pybot or dual-arm SCARA printers like the RepRap Morgan.

Continue reading “Small Footprint Scara Laser Engraver Has Massive Build Area” →

Hackaday Podcast 121: Crazy Bikes, DIY Flip Dots, EV Mountain Climbing, And Trippy Tripterons

June 4, 2021 by Mike Szczys 3 Comments

Hackaday editors Mike Szczys and Elliot Williams discuss a great week of hardware hacks. Two delightful mechanical hacks focus on bicycles: one that puts a differential on the front fork, and the other a flywheel between the knees. Elliot was finally impressed by something involving AI — a machine-learning guitar pedal. You’ve heard of a delta bot? The tripteron is similar but with a single rail for the three arms. After a look at flip dots, tiny robots, and solar air planes we close the show geeking out about racing electric vehicles up a hill and stories of the hardware that has made closed captions possible.

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 (55 MB or so.)

Places to follow Hackaday podcasts:

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IRC Will Never Die

May 22, 2021 by Elliot Williams 51 Comments

The big kerfuffle in the open source world this week surrounds the biggest IRC server operator, Freenode. Wherever the dust settles, myriad important open source projects use Freenode’s IRC servers for their main channel of user feedback, and a number of vibrant communities call or called Freenode home. What you would call a 3D printer, and most of the software that drives it, for instance, was brainstormed up in Freenode’s #reprap. If you want help with a Linux distribution, you’ll be set straight within a few minutes in the relevant channel, because the people who wrote, packaged, or maintain it are probably on Freenode waiting to chat.

But suppose Freenode burns to the ground tomorrow, as some are suggesting. So what? My take is that is doesn’t matter. Freenode doesn’t own IRC, setting up an IRC server is essentially trivial, and what’s really important is the online community — they can just pick up and move somewhere else with very little hassle.

This is not to say that we don’t all benefit from the diligence that Freenode’s volunteer administrators and operators have donated to the cause over the years. IRC servers don’t run themselves, and Freenode’s admins fought and won an epic battle with spammers a couple years back. Keeping IRC running at scale is a different thing than setting up something for your friends, and so the Freenode folks definitely deserve our thanks.

But look, IRC is an old protocol and it’s a simple protocol. It’s so simple, in fact, that writing an IRC bot is just a few dozen lines in Python, using no external libraries. All you need to do is send plain text over a socket. You can do this — it makes a great networking hello world.

IRC is fun for hackers, but if you want a user-friendly GUI client, you ridiculously many to choose from. There are even no-install web clients if you just want to dip your toes in. Heck, you could install your own server in an hour or so.

So saying that the demise of Freenode is the end of IRC is a lot like saying that the end of Hotmail was the end of e-mail. In the grand scheme of things, almost nobody actually uses IRC — Freenode has 78,000 users while Slack has 10 million — and IRC users are very savvy, if not full-on geeky. These are the sort of people who can probably find the server field in a menu and change it from irc.freenode.net to irc.whatever.org.

In addition to our traditional #hackaday channel on irc.freenode.net, there’s also a channel set up on irc.libera.chat as well. There isn’t much action in either — IRC tends to be a slow conversation, so don’t freak out if someone responds to you an hour later — but if you want to swing by, we’re there. IRC will never die!

2021 Hackaday Prize Begins!

If you missed our announcement, this year’s Hackaday Prize is on! We’ve all had a rough year and a half, and it’s lead a lot of us to think seriously about our world. How would you want to change it going forward? Fifty entrants will rethink, refresh, and rebuild their way into $500, and the Grand Prize is $25,000. Get hacking!

Plotter Uses Dual Disks

February 19, 2021 by Al Williams 19 Comments

If you want to move a pen (or a CNC tool, or a 3D printing hot end) in the X and Y plane, your choices are typically pretty simple. Many machines use a simple cartesian XY motion using two motors and some sort of linear drive. There’s also the core-XY arrangement where two motors move belts that cause the head to travel in two directions. Delta printers use yet another arrangement, but one of the stranger methods we’ve seen is the dual disk polar printer which — as its name implies — uses two rotating disks.

The unique mechanism uses one motor to rotate a disk and another motor to rotate the entire assembly. The print head — in this case a pencil — stays stationary. as you can see in the video below.

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This GCode Post-Processor Squeezes Lines Into Arcs

November 3, 2020 by Sonya Vasquez 34 Comments

When the slicer software for a 3D printer model files into GCode, it’s essentially creating a sequential list of connected line segments, organized by layer. But when the features of the original model are dense, or when the model is representing small curves, slicers end up creating a proliferation of teeny segments to represent this information.

This is just the nature of the beast; lots of detail translates into lots of teeny segments. Unfortunately, some printers actually struggle to print these models at the desired speeds, not because of some mechanical limitation, but because the processor cannot recalculate the velocities of these segments fast enough. The result is that some printers simply stutter or slow down the print, resulting in print times that are much higher than they should be.

Enter Arc Welder, a GCode compression tool written by [FormerLurker] that scrutinizes GCode files, hunts for these tiny segments, and attempts to replace contiguous clusters of them with a smaller number of arcs. The result is that the number of GCode commands needed to represent the model drop dramatically as connected clusters of segment commands become single arc commands.

“Now wait”, you might say, “isn’t an arc an approximation of these line segments?” And yes–you’re right! But here lies the magic behind Arc Welder. The program is written such that arcs only replace segments if (1) an arc can completely intersect all the segment-to-segment intersections and (2) the error in distance between segment and arc representation is within a certain threshold. These constraints act such that the resulting post-processing is true to the original to a very high degree of detail.

A concise description of Arc Welder’s main algorithm as pulled from the docs

This whole program operates under the assumption that your 3D printer’s onboard motion controller accepts arc commands, specifically G2 and G3. A few years ago, this would’ve been uncommon since, technically, 3D printing and STL file only requires moving in straight line segments. But with more folks jumping on the bandwagon to use these motion control boards for other non-printing applications, we’re starting to see arc implementations on boards running Marlin, Smoothieware, and the Duet flavor of RepRap Firmware.

For the curious, this program is kindly both well documented on operating principles and open source. And if [FormerLurker] seems like a familiar name before–you’d be right–as they’re also the mind behind Octolapse, the 3D printing timelapse tool that’s a hobbyist crowd favorite. Finally, if you give Arc Welder a spin, why not show us what you get in the comments?

Thanks for the tip [ImpC]!

Open And Sustainable Engineering Hack Chat

August 17, 2020 by Dan Maloney No comments

Join us on Wednesday, August 19 at noon Pacific for the Open and Sustainable Engineering Hack Chat with Joshua Pearce!

Since the first of our hominid ancestors learned to pick up a rock and make it into a tool, we humans have been using our engineering skills to change the world. For most of the 2 million or so years since that first technological leap, natural materials like stone and wood were the focus of our engineering projects, and except for a few tantalizing remnants, most of what was built has returned to the Earth whence it came.

Then we discovered other materials; we learned to free metals from rocks and how to harvest the fossilized hydrocarbon remains of ancient plants. Iron, aluminum, plastic, and silicon became our stock in trade, and the planet is now layered so thick with these materials and the byproducts of harvesting them that a new geological epoch, the Anthropocene Epoch, has been proposed to cover this time of human activity and its impact on the geological record.

But if we humans are clever enough to make such an impact, we should be clever enough to think our way out of the mess, and wise enough to see the need. That’s where the efforts of Dr. Pearce’s research at the Michigan Tech Open Sustainability Technology (MOST) lab are focused. Dr. Pearce envisions a sustainable future powered by pervasive solar photovoltaic systems and using open-source technologies like 3D printing to drive new models for manufacturing. We’ve recently seen interesting work from his lab, like this grinder that makes custom compression screws for plastic recycling. The MOST page on Hackaday.io is filled with other great examples of the technology that supports their mission, from low-cost environmental testing instruments to 3D-printable microfluidics.

Dr. Pearce will join us on the Hack Chat to talk about open and sustainable engineering. Be sure to stop by with your questions and to find out what you can do to engineer a brighter future, starting right in your own shop.

Our Hack Chats are live community events in the Hackaday.io Hack Chat group messaging. This week we’ll be sitting down on Wednesday, August 19 at 12:00 PM Pacific time. If time zones baffle you as much as us, we have a handy time zone converter.

Click that speech bubble to the right, and you’ll be taken directly to the Hack Chat group on Hackaday.io. You don’t have to wait until Wednesday; join whenever you want and you can see what the community is talking about.

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Feeding Both Filament And Electrons Through A Custom D-Sub Connector

December 13, 2019 by Danie Conradie 28 Comments

We sometimes forget that 3D printers are just CNC platforms with a hotend attached, and there a whole range of alternative tool heads to use. [Jón Schone] has been doing exactly that, and needed a way to quickly disconnect his hotend completely from his printer, so he 3D printed his own custom D-sub connector for both filament and wires. (Video, embedded below.)

[Jon] has added a number of upgrades for his Creality CR10 3D printer, including a quick change tool mount to allow him to also use a laser engraver and even a small spindle. When the hotend is removed there’s no way to quickly disconnect the wiring , so the print head is usually left connected and placed to one side of the printer. For a quick detach solution for both wiring and the Bowden tube, he first modified an off-the-shelf D-sub connector. The connector was relatively expensive, and the tube had a tendency to pop out, which led to some failed prints.

[Jon] wanted to use proper Bowden tube fittings inside the connector, so he designed and printed his own D-sub connector and bought loose contacts. Pushing the contacts into the housing turned out to be quite difficult to do without breaking them, so he’s working on making that process simpler. This is just one of many examples of 3D printing 3D printer upgrades, which has been a core feature of the RepRap project right from the beginning. Check out the video after the break

We have no shortage of 3D printer hacks and there will be many more to come. Some cool recent ones includes the Jubilee CNC that was built from the start with automatic tool changing in mind, and a printer that fits in your backpack. Continue reading “Feeding Both Filament And Electrons Through A Custom D-Sub Connector” →