cnc hacks

912 Articles

DIY CNC Uses Lots Of 3D-Printed Parts

November 5, 2021 by 21 Comments

There are probably almost as many DIY CNC designs as there are DIY CNCs. And there’s nothing wrong with that! We really liked [maxvfischer’s] documentation on GitHub for a machine he made based on a design by [Ivan Miranada].

In addition to a complete bill of materials, there are Fusion 360 files and very good instructions. There are several tips that seemed like they would help even if you were building similar machines.

The machine uses HTD5M belts instead of the more prevalent lead screw design. Everything slides on MGN12H slides. There are detailed photographs covering not just the tricky parts but even how to extend the stepper motor wires.

The original design used a Makita RT0700C for the spindle, but [max] couldn’t find one of those, but found a similar version with the same dimensions.

The only tip we would add is to be careful using taps in a handheld drill. (Don’t ask us how we know that.) A drill press is safer, or you can even use a tap handle and do it the old-fashioned way.

The firmware is grbl on an Arduino, and there are complete instructions for setting that up, too. We were amazed at the number of pictures included along with the detailed description. If you were ever afraid you couldn’t duplicate a CNC project, this might be the one to tackle.

There are, of course, cheaper and simpler options with fewer capabilities. Some are even almost free courtesy of the local dumpster.

an image of the graffomat at work

Automate Your Graffiti With The Graffomat!

September 30, 2021 by 30 Comments

In Banksy’s book, Wall and Piece, there is a very interesting quote; “Imagine a city where graffiti wasn’t illegal, a city where everybody could draw whatever they liked…”. This sounds like it would be a very exciting city to live in, except for those of us who do not have an artistic bone in their body. Luckily, [Niklas Roy] has come up with the solution to this problem; the Graffomat, a spray can plotter.

The Graffomat is, in its creator’s own words, a “quick and dirty graffiti plotter.” It is constructed primarily from wood and driven by recycled cordless drills that pulls string pulleys to move the gantry.  The Arduino Nano at the heart of the Graffomat can be controlled by sending coordinates over serial. This allows for the connection of an SD card reader to drip-feed the machine, or a computer to enable real-time local or over-the-internet control.

We are especially impressed with how [Niklas] handled positional tracking. The cordless drills were certainly not repeatable like a stepper motor, as to allow for open-loop control. Therefore, the position of the gantry and head needed to be actively tracked. To achieve this, the axes are covered with black and white striped encoder strips, that is then read by a pair of phototransistors as the machine moves along. These can then be paired with the homing switches in the top left corner to determine absolute position.

Graffomat is not the first automated graffiti machine we’ve covered. Read here about the robot that painted murals by climbing smokestacks in Estonia. 

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Small low-cost CNC mill with rotary tool

Minimal Mill: The Minamil

September 10, 2021 by 35 Comments

Having a few machine tools at one’s disposal is a luxury that not many of us are afforded, and often an expensive one at that. It is something that a large percentage of us may dream about, though, and with some commonly available tools and inexpensive electronics a few people have put together some very inexpensive CNC machines. The latest is the Minamil, which uses a rotary tool and straps it to an economical frame in order to get a functional CNC mill setup working.

This project boasts impressively low costs at around $15 per axis. Each axis uses readily available parts such as bearings and threaded rods that are readily installed in the mill, and for a cutting head the build is based on a Dremel-like rotary tool that has a similarly low price tag. Let’s not ignore the essentially free counterweight that is used.

For control, an Arduino with a CNC shield powers the three-axis device which is likely the bulk of the cost of this project. [Paul McClay] also points out that a lot of the material he needed for this build can be salvaged from things like old printers, so the $45 price tag is a ceiling, not a floor.

The Minamil has been demonstrated milling a wide variety of materials with excellent precision. Both acrylic and aluminum are able to be worked with this machine, but [Paul] also demonstrates it in its capacity to mill PCBs. It does have some limitations but for the price it seems that this mill can’t be beat, even compared to his previous CNC build which repurposed old CD drives.

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Minimalist Robot Arm Really Stacks Up

August 19, 2021 by 7 Comments

There’s nothing like a little weekend project, especially one that ends up better than you expected. And when you literally build a robotic arm out of workshop scraps, so much the better.

Longtime readers will no doubt recognize the build style used here as that of [Norbert Heinz], aka “Homofaciens” on YouTube. [Norbert] has a way of making trash do his bidding, and has shown us all kinds of seemingly impossible feats of mechatronics with just what’s lying around. In this case, his robot arm is made from scrap wooden roofing battens, or what we’d call furring strips here in the US. The softwood isn’t something you’d think would make a great material for building robots, but [Norbert] makes its characteristics work for him, like using wax-lubricated holes for hinge points. Steppers and lead screws cannibalized from an old CNC build, along with the drive electronics, provide the motion. It’s a bit — compliant — but precise enough to pick up nuts and stack them nicely. The video below gives an overview of the build, and detailed instructions are available too.

We always appreciated [Norbert]’s minimalist builds, and seeing what can be accomplished with almost nothing is always inspirational. If you’re not familiar with his work, check out his cardboard and paperclip CNC plotter, his tin can encoders, or his plasma-powered printer.

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Giant CNC Machine Measures A Full Cubic Meter

August 8, 2021 by 32 Comments

There are plenty of designs for table-top 3D printers, engravers, and general CNC machines out there. However, if you wanna build big things and build them fast, sometimes you need a machine that can handle bigger jobs. This gigantic 1x1x1 m 5-axis CNC machine from [Brian Brocken] absolutely fits the bill.

The build relies on 3D-printed components and aluminium tubing to make it accessible for anyone to put together. [Brian] notes that 25×25 mm tubing with a 2 mm wall thickness does an okay job, but those aiming to minimize deflection would do well to upgrade to 5 mm thickness instead. Stepper motors are NEMA 23 size, though the Y-axis uses a pair of NEMA 17s. This is necessary to deal with the immense size of the machine. Control is thanks to an Arduino Mega fitted with a RAMPS board, running the Marlin firmware.

The plan is to use the machine to test out a variety of CNC machining techniques. It could make for a great maxi-sized 3D printer, and should be able to handle some basic 5-axis milling of very soft materials like foams. This might seem silly on the face of it, but it can be of great use for mold making tasks.

We’ve seen giant CNC routers built before, too, and they can readily be put to great use. Video after the break.

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Custom Caliper Tracks For When You’re Going The Distance

August 5, 2021 by 15 Comments

The working principle of digital calipers is mysterious enough that we’d never think to dismantle, much less improve them, right? Well, think again, as [Limi DIY] retrofits the processing element onto a custom track, extending the calipers measurement distance to a whopping 650 mm. Combined with a prior project to extract the measurement data, the result makes for a working multi-axis digital readout, a handy device for machine tools like a manual lathe or milling machine.

Digital calipers operate on the principle of measuring an array of variable capacitors. If we scratch our heads and look back at our physics notes, we’ll recall that the capacitance between two parallel conductive plates is linearly proportional to the surface area. By fixing one dimension of both plates and by sliding one plate over the other, we effectively change the area, giving ourselves a simple linear displacement sensor! (There are some classy error-correcting techniques too, and this [PDF] is a great place to look for more details.)

The theory takeaway is that this array of parallel plates can be embedded directly into a printed circuit board. We just need to know the dimensions. After some close measurement work, [Limi DIY] extracted the crucial measurements and fabbed a PCB with the pattern duplicated over 650 mm. After retrofitting the original processing element onto this new track, they had a working measurement device that’s far longer than the original!

If you’ve ever been tempted to disassemble your calipers but too nervous to bite off the investment, now’s your chance to follow along as [Lima DIY] demonstrates the gratuitous disassembly process for you in video format. And the fruits of their labor is also captured on a project post that includes the key dimensions if you’re looking to do the same thing.

If you’re looking for other ways to improve your calipers, why not start by giving them a major battery life boost.

Thanks to [absd] via [Jubilee Discord] for the tip!

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Upgrade A 3D Printed CNC Milling Machine By Using It

August 4, 2021 by 22 Comments

One of the original ideas behind the RepRap project was for the machines to create their own upgrades. That philosophy is shining brightly in [Ivan Miranda] CNC milling machine project, which has been used to upgrade its aluminum and 3D printed frame components to steel.

For precision machining on hard metal, machine rigidity is of utmost importance. [Ivan]’s original CNC mill made extensive use of lightweight aluminum extrusions with 3D printed fittings. The machine worked, but the lack of rigidity was visible in the surface quality of the machine parts. The latest upgrade included a completely new frame from welded steel tubing and heavy aluminum mounting plates. The original machine was used to slowly machine slots in the steel tubes to retain the adjustability of the Z-axis. Some of the 3D printed motor mounts remained, so in the second video after the break [Ivan] used the newly upgraded machine to mill some aluminum replacements.

While this machine might not be perfect, we have to respect [Ivan]’s willingness to toss himself in at the deep end and show all failures and lessons learned the hard way. This project was clearly used as an opportunity to improve his welding and machining skills. His fabrication skills have come a long way from mainly 3D printed projects like the giant tracked tank and screw tank.

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