[Perry] was interested in adding a 4th axis to his CNC machine, but not very excited at the prospect of spending hundreds of dollars on the parts and electronics to make it work. There is a very clever and very inexpensive way to add a 4th axis to a CNC machine, though, and after a bit of fabrication, he was able to add a ‘rolling’ 4th axis to his machine.
The idea for this build comes from [Bob] over on the CNC Shark forums. Instead of adding a motor to rotate a work piece around, [Bob]’s build simply mounts it between two jaws, and rolls everything around against the bed of the CNC router. Don’t have a clue what that means? Check out the picture to the right, and you’ll see brilliance built in Delrin and HDPE. By mounting two rack gears to the bed and two geared jaws to the carriage of the machine, moving the router in the Y axis also rotates the 4th axis. This is far, far too clever; it doesn’t require any additional electronics and the only software tweaks are a bit of G-code hacking.
[Perry] took one look at [Bob]’s project and decided this would be the perfect build to get him a 4th axis. The parts for this build were fabricated out of black HDPE, with the only real change to the design being a ‘variable length’ 4th axis. Instead of two rack gears mounted to the bed of the machine, [Perry]’s build only uses one rack, with the other end simply rolling on the bed.
There are a lot of clever inventions that don’t work, so what’s the verdict with this CNC hack? It actually looks pretty good. [Perry] was able to turn some square stock into round stock, and able to engrave a spiral around a cylinder. You can check out those videos below.
[Frank Howarth] has a shop most woodworkers would kill for, stuffed with enough tools to equip multiple hackspaces — four radial-arm saws alone! But while the CNC router in the middle of the shop, large enough to work on an entire sheet of plywood, is a gem of a machine, it was proving to be a dusty nightmare. [Frank]’s solution was as unique as his workspace — this swiveling overhead dust extraction system.
The two-part video below shows how he dealt with the dual problems of collection and removal. The former was a fairly simple brush-bristle shroud of the type we’ve featured before. The latter was a challenge in that the size of the router’s bed — currently 8′ but soon to be extended to 12′ — and the diameter of the hoses needed to move enough air made a fixed overhead feed impractical. [Frank]’s solution is an overhead trolley to support the hoses more or less vertically over the router while letting the duct swivel as the gantry moves around the work surface. There were a few pitfalls along the way, like hoses that shorten and stiffen when air flows through them, but in the end the system works great.
Using a CNC router is a dusty business if your material of choice is wood. Sure, you can keep things tidy by chasing the cutter around the table with a shop vac, but that sort of takes the fun out of having a machine that can make cuts without you. The big boy machines all have integrated dust collection, and now you can too with this 3D-printed CNC router dust shoe.
Designed specifically for the X-Carve with a DeWalt 611 router, [Mark Edstrom]’s brush is a simple design that’s almost entirely 3D printed. The shroud encloses the router body and clamps to the mounting bracket, totally surrounding the business end of the machine. The cup is trimmed with a flexible fringe to trap the dust and guide it to the port that fits a small (1-1/4″ diameter) shop vac hose. The hose is neatly routed along the wiring harness, and the suction is provided by a standard shop vac.
Files for the cup are up on Thingiverse; we suspect it’d be easy to modify the design to work with other routers and dust collectors. You might even find a way to shroud a laser cutter and capture the exhaust with a DIY filter.
You may have a few questions regarding [ThisOldTony]’s effort. First, unless you’re familiar with machine tooling, you may wonder what exactly a boring head is. The video below makes it plain, but the short answer is that it’s a tool to make holes. A boring head spins a boring bar with a cutting tool, and the head can be offset to spin the bar through an adjustable diameter. They’re great for making large holes of precise diameters – skip to around 25:30 to see it in action.
The other question might be: why does he spend so much time and effort building something he can just buy off the shelf? If you have to ask that question, we think you may be missing the point. [Tony] seems mainly interested in building tools; using them to make non-tool things is merely a happy accident. We totally respect that, and besides, just look at the quality of the tool he makes. We find his videos very entertaining, too – he’s got a great sense of humor and the video production quality is top-notch. Just watch out for banana peels and space-time continuum issues.
Drag Knives seem to be the overshadowed awkward kid on the playground of CNC equipment, but they have a definitive niche making stencils, vinyl stickers, and paper cuts. Unfortunately, the drag knife blades for CNC routers are pricey — over $100 for a single blade. [Brian] at the Grunblau Design Studio took the price point as a challenge to build his own end-effector. A few iterations later, he’s created his very own drag knife blade tool that accepts replaceable steel blades for cutting.
From constraint-driven concept, to a 3D printed proof-of-concept, to a fully machined aluminum prototype, [Brian’s] efforts hit all the highlights of a well-engineered project. At the end of the day, dull blades can be swapped for a few dollars, rather than shelling out another $150 for the off-the-shelf variant. We’ve seen bootstrapped CNC vinyl cutters before, but nothing that takes an original re-envisioning of the tool itself.
The video below will no doubt remind you about previous versions of [HomoFaciens]’ CNC builds, which we’ve covered in depth. With an eye to spending as little as possible on his builds, most parts are recovered from e-waste, with a fair amount of Dumpster diving thrown in. For this upgrade, the salvaged brushed DC motors with their signature gap-toothed encoder disks are replaced with genuine bipolar steppers. The primary intention of his build is to learn (and teach) as much as possible, so he spends a good amount of time going over steppers and their control – how to determine phase wiring, how to wire up the not-salvaged-but-still-cheap drivers, directional control, and half-stepping. The mechanics are decidedly dodgy, but there are clever expedients aplenty – we especially like the oil cup fabricated from a brass tube and a bolt with a hole drilled in it. Everything just works, and the results to expense ratio is hard to beat.
While we appreciate the upgrades here, we’re still keen to see how junky his other trash can CNC can get. And we’re still waiting on the paper clip and cardboard challenge.
OK, we exaggerate a little – but only a little. Apart from the control electronics, almost everything in [HomoFacien]’s build could be found by the curb on bulk-waste pickup day. Particle board from a cast-off piece of flat-pack furniture, motors and gears from an old printer, and bits of steel strapping are all that’s needed for the frame of a serviceable CNC machine. This machine is even junkier than [HomoFacien]’s earlier build, which had a lot more store-bought parts. But the videos below show pretty impressive performance nonetheless.
Sure, this is a giant leap backwards for the state of the art in DIY CNC builds. but that’s the point – to show what can be accomplished with almost nothing, and that imagination and perseverance are more important for acceptable results than an expensive BOM.
With that in mind, we’re throwing down the gauntlet: can anyone build a CNC machine from cardboard and paperclips?