Skateboard Wheels Add Capabilities To Plasma Cutter

July 28, 2025 by Bryan Cockfield 4 Comments

Although firmly entrenched in the cultural zeitgeist now, the skateboard wasn’t always a staple of popular culture. It had a pretty rocky start as surfers jankily attached roller skating hardware to wooden planks searching for wave-riding experiences on land. From those rough beginnings it still took decades of innovation until Rodney Mullen adapted the ollie for flatground skating before the sport really took off. Skateboard hardware is quite elegant now too; the way leaning turns the board due to the shape of the trucks is immediately intuitive for even the most beginner riders, and bearing technology is so high-quality and inexpensive now that skateboard hardware is a go-to parts bin grab for plenty of other projects like this plasma cutter modification.

[The Fabrication Series]’s plasma cutter is mounted to a CNC machine, allowing for many complex cuts in much less time than it would take to do by hand. But cutting tubes is a more complicated endeavor for a machine like this. This is where the skateboard hardware comes in: by fabricating two custom pivoting arms each with two skateboard wheels that push down on a tube to hold it in place, the CNC machine can roll the tube along the table in a precise way as the plasma cutter works through it.

Of course, cutting a moving part is a little more complicated for the CNC machine than cutting a fixed piece of sheet metal, so [The Fabrication Series] walks us through a few ways of cutting pipe for various purposes, including miters and notches. The first step is to build a model of the pipes, in this case using Onshape, and then converting the 3D model of the pipes into a sheet metal model that the CNC machine can use. It does take a few cuts on the machine to fine-tune the cuts, but in no time the machine is effortlessly cutting complex shapes into the pipe. Don’t have a plasma cutter at all? You can always build your own from scratch.

Thanks to [JohnU] and [paulvdh] for the tip!

Continue reading “Skateboard Wheels Add Capabilities To Plasma Cutter” →

High Frequency Food: Better Cutting With Ultrasonics

March 21, 2025 by Lewin Day 37 Comments

You’re cutting yourself a single slice of cake. You grab a butter knife out of the drawer, hack off a moist wedge, and munch away to your mouth’s delight. The next day, you’re cutting forty slices of cake for the whole office. You grab a large chef’s knife, warm it with hot water, and cube out the sheet cake without causing too much trauma to the icing. Next week, you’re starting at your cousin’s bakery. You’re supposed to cut a few thousand slices of cake, week in, week out. You suspect your haggardly knifework won’t do.

In the home kitchen, any old knife will do the job when it comes to slicing cakes, pies, and pastries. When it comes to commercial kitchens, though, presentation is everything and perfection is the bare minimum. Thankfully, there’s a better grade of cutting tool out there—and it’s more high tech than you might think.

Continue reading “High Frequency Food: Better Cutting With Ultrasonics” →

Hackaday Prize 2023: Machining Metals With Sparks

August 8, 2023 by Bryan Cockfield 3 Comments

Working with metals can present a lot of unique challenges even for those with a fairly well-equipped shop. Metals like aluminum and some types of steel can be cut readily with grinders and saws, but for thick materials or some hardened steels, or when more complex cuts need to be made, mechanical cutting needs to be reconsidered in favor of something electric like electrical discharge machining (EDM) or a plasma cutter. [Norbert] has been on the path of building his own EDM machine and walks us through the process of generating a spark and its effects on some test materials.

Armed with a microscope, a homemade high-voltage generator, drill bit, and a razor blade to act as the workpiece, [Norbert] begins by experimenting with electrical discharges by bringing the energized drill bit close to the razor to determine the distance needed for effective electrical machining. Eventually the voltage is turned up a bit to dive into the effects of higher voltage discharges on the workpiece. He also develops a flushing system using de-ionized water, and then finally a system to automate the discharges and the movement of the tool.

While not a complete system yet, the videos [Norbert] has created so far show a thorough investigation of this metalworking method as well as some of the tricks for getting a setup like this working. EDM can be a challenging method for cutting metal as we’ve seen before with this similar machine which uses wire as the cutting tool, but some other builds we’ve seen with more robust electrodes have shown some more promise.

Continue reading “Hackaday Prize 2023: Machining Metals With Sparks” →

CNC Feeds And Speeds, Explained As A First-Timer

May 5, 2023 by Donald Papp 35 Comments

If you’ve ever looked into CNC cutting tools, you’ve probably heard the term “feeds and speeds”. It refers to choosing the speed at which to spin the cutting tool, and how fast to plow it into the material being cut. They’re important to get right, and some of the reasons aren’t obvious. This led [Callan Bryant] to share his learned insights as a first-timer. It turns out there are excellent (and somewhat non-intuitive) reasons not to simply guess at the correct values!

A table of variables and how they relate to one another (click to enlarge).

The image above shows a tool damaged by overheating. [Callan] points out that as a novice, one might be inclined to approach a first cutting jobs conservatively, with a low feed rate. But doing this can have an unexpected consequence: a tool that overheats due to spinning too quickly while removing too little material.

CNC cutting creates a lot of heat from friction, and one way to remove that heat is by having the tool produce shavings, which help carry heat away. If a tool is making dust instead of shavings — for example if the feed rate is too conservative — the removed pieces will be too small to carry significant energy, and the tool can overheat.

[Callan] makes a table of variables at work in a CNC system in order to better understand their relationship before getting into making a formula for calculating reasonable feed and speed rates. Of course, such calculations are a reasonable starting point only, and it’s up to the operator to ensure things are happening as they should for any given situation. As our own Elliot Williams observed, CNC milling is a much more manual process than one might think.

Cutting Metals With A Diode Laser?

September 21, 2022 by Dave Rowntree 34 Comments

Hobbyist-grade laser cutters can be a little restrictive as to the types and thicknesses of materials that they can cut. We’re usually talking about CO₂ and diode-based machines here, and if you want to cut non-plastic sheets, you’re usually going to be looking towards natural materials such as leather, fabrics, and thin wood.

But what about metals? It’s a common beginner’s question, often asked with a resigned look, that they already know the answer is going to be a hard “no. ” However, YouTuber [Chad] decided to respond to some comments about the possibility of cutting metal sheets using a high-power diode laser, with a simple experiment to actually determine what the limits actually are.

Using an XTool D1 Pro 20W as a testbed, [Chad] tried a variety of materials including mild steel, stainless, aluminium, and brass sheets at a variety of thicknesses. Steel shim sheets in thicknesses from one to eight-thousandths of an inch appeared to be perfectly cuttable, with an appropriate air assist and speed settings, with thicker sheets needing a good few passes. You can definitely see the effect of excess heat in the workpiece, resulting in some discoloration and noticeable warping, but those issues can be mitigated. Copper and aluminium weren’t touched by the beam at all, likely due to the extra reflectivity, but we do have to wonder if appropriate surface treatments could improve matters.

Obviously, we’ve seen that diode lasers can have an impact on metals, simply smearing a little mustard on the workpiece seems to make marking a snap. Whilst we’re on the subject of diode lasers, you can get a lot of mileage from just strapping such a laser module onto a desktop CNC.

Continue reading “Cutting Metals With A Diode Laser?” →

Autonomous Mower Hits Snag

February 28, 2022 by Bryan Cockfield 10 Comments

Interfacing technology and electronics with the real world is often fairly tricky. Complexity and edge cases work their way in to every corner of a project like this; just ask anyone who has ever tried to operate a rover on Mars, make a hydroponics garden, or build almost any robotics project. Even those of us who simply own a consumer-grade printer are flummoxed by the ways in which they can fail when manipulating single sheets of paper. This robotic lawnmower is no exception, driving its creator [TK] to extremes to get it to mow his lawn.

[TK] actually had a platform for his autonomous mower ready to go thanks to a previous build using this solar-powered robot to explore the Australian outback. Adding another motor to handle the grass trimming seemed simple at first and he set about wiring it all up and interfacing it to the robot. After the first iteration he found the robot was moving too fast to effectively cut the grass, so he added a more powerful cutting motor and a gearbox to help the mower crawl more slowly over the lawn. Disaster struck when his 3D printed mount for the steel cutting blades shattered, but with [TK] uninjured he pushed on with more improvements.

As it stands right now, the mower can effectively cut the grass moving forward even with the plastic-only cutting blades that [TK] is using now for safety reasons. The mower stripped its reverse gear so there still are some improvements to make before this robot is autonomously cutting the lawn without supervision. Normally we see lawnmowers retrofitted with robotics rather than robotics retrofitted with a lawnmower, but we’re excited to see any approach that lets us worry about one less household chore.

Thanks to [Rob] for the tip!

Continue reading “Autonomous Mower Hits Snag” →

Fail Of The Week: A Bigger Hacksaw Isn’t A Better Hacksaw

February 14, 2022 by Dan Maloney 23 Comments

If we’re being honest, the main reason to buy a power tool is to avoid the pain of using one’s muscles. Oh sure, we dress it up with claims that a power tool will make us more productive, or give better results, but more often than not it’s the memory of how your forearm feels after a day of twisting a screwdriver that makes you buy a cordless driver.

It appears that [Artisan Makes] has a high tolerance for pain, seeing how the main prep tool in his metal shop is a plain old hacksaw. So in an effort to speed up his stock prep, he turned not to a bandsaw or cutoff saw, but instead built the world’s silliest hacksaw. It’s the metalworking equivalent of the two-man bucksaws that lumberjacks used to fell trees before chainsaws came along, and at a meter and half in length, it’s about the size of one too. Modifying the frame of his trusty hacksaw was easy — he just popped the end pieces off and attached them to an extra-long piece of tube stock. Finding a 1.5-meter hacksaw blade was the main challenge; not exactly a big-box store item, that. So a section of metal-cutting bandsaw blade was modified to fit the frame, and it was off to the races.

Or not. The video below tells the tale of woe, which starts with the fact that [Artisan]’s shop is too small for the hilariously long hacksaw. Solving the fixturing problems didn’t soo much to help, though — there was no way to tension the blade enough to get it to stop wobbling during cutting. It was also clear that the huge saw wasn’t able to apply enough downforce on the stock to get good cuts. Maybe with a second set of hands, though…

There are plenty of ways to improve hacksawing in the shop, and while this isn’t one of them, we sure appreciate the chuckle we got out of it. And you really should check out [Artisan Makes]’ channel — his more serious stuff is really good.

Continue reading “Fail Of The Week: A Bigger Hacksaw Isn’t A Better Hacksaw” →