Custom Lathe Tool Cuts Complex Oil Grooves

September 8, 2022 by 41 Comments

Oil grooves are used to lubricate the inside of a bearing, and can come in many forms — from a single hole that takes a few drops of oil, to helical patterns that distribute it over the entire internal surface. The ideal arrangement is a looping figure eight pattern similar to an oscilloscope Lissajous figure, but cutting these is a nightmare. That is, unless you’ve got the proper tool.

We figure [Machine Mechanic] must need to cut a lot of them, as they spent quite a bit of time perfecting this custom lathe attachment to automate the process. Through an assortment of clever linkages and a rod-turned-crank that was welded together in-situ, the device converts the rotational motion of the lathe into a reciprocating action that moves the cutting tool in and out of the bearing. Incidentally the business end of this gadget started life out as a bolt, before it was turned down and had a piece of tool steel brazed onto the end.

With a little adjustment, it seems like this device could also be used to carve decorative patterns on the outside of the workpiece. But even if this is the only trick it can pull off, we’re still impressed. This is a clever hack for a very specialized machine shop operation that most would assume you’d need a four-axis CNC to pull off.

Lathes seem at first like rather single purpose machines, we’re always pleased to discover strange and wonderful things being done with them, like this seemingly impossible-to-turn piece, and this combo wire EDM and lathe.

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Cut Just About Anything With This Combination Lathe And Wire EDM

July 20, 2022 by 18 Comments

They say that if you have a lathe, you have every other machine tool too. To some degree, that’s true — you can make almost anything on a lathe, including another lathe, and even parts best made on other machine tools can usually be made on a lathe in a pinch. But after seeing this lathe attachment for a DIY electric discharge machining tool, we might be inclined to see the EDM as the one machine tool to rule them all.

Now, we’ll admit that the job [BAXEDM] built this tool for might be a little contrived. He wanted to make some custom hex inserts for his Swiss Army knife, which seem like they’d have been pretty easy to make from hex bar stock in a conventional lathe. Then again, hardened steel is the kind of material that wire EDM was made for, and there seem to be many use cases for an attachment that can spin a workpiece against an EDM cutting wire.

That was really the trick of this build — spinning a part underwater. To accomplish this, [BAXEDM] built a platform to carry a bearing block that supports a standard ER-25 collet, with a bracket that holds a stepper clear of the water in the EDM cutting tank. There are plenty of 3D printed insulators too, to keep most of the attachment electrically isolated from the EDM current, plus exotic parts like ceramic bearings that won’t corrode under water. There were a ton of other considerations, too; [BAXEDM] goes through the long iterative design process in the video below, as well as taking his new tool for a literal spin starting at about the 27:00 mark.

If you’re intrigued by what EDM can accomplish — and who wouldn’t be? — but you need more background on the process, we’ve got you covered.

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AR Display Shows CNC Lathe Operations In Real Time

February 16, 2022 by 16 Comments

[Kent VanderVelden] has come up with an interesting AR system to assist operators who are monitoring CNC lathes. (video, embedded, below) The idea is to first produce a ‘frozen’ video stream of the workpiece. This was achieved by placing a high-speed camera above the lathe, and triggering an image capture, synchronized to the rotational position of the workpiece. A high-speed rotary encoder, attached to the tailstock via a belt drive, feeds the current position into an Altera Terasic DE-Nano FPGA eval board. This is then compared to the position from another encoder, doing duty as an angular set point control. The resulting signal is used as the camera trigger to generate a video stream of just the frames where the angle is as selected by the operator, thus giving the impression of a frozen position. The video stream is sent over to a client device based on a Raspberry Pi 4 with a UPS hat, allowing it to be portable.

High speed rotary encoder driven via a belt

This video stream is overlaid with details of the current machine position, as well as the LinuxCNC G-code being executed and a graphical representation of the operation being performed by the machine. This combined video is then fed to a Vufine VUF-110 wearable, which is minimally invasive, allowing the operator to clearly see the machine of interest. As [Kent] suggests, there are many possible usage scenarios for such a setup, including remote monitoring of multiple operating machines by a single operator.

We’ve seen a few neat machine hacks over the years, here’s a nice project adding a programmable power feed to an old lathe, and since wood lathes are often missing out some DRO love, here’s a nice way to tell them that you care.

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Mini-lathe carriage wheel

Improving A Mini-Lathe With A Few Clever Hacks

November 13, 2021 by 21 Comments

Like many budget machinists, the delightfully optimistically named [We Can Do That Better] had trouble with some of the finer controls on his import mini-lathe. But rather than suffer through it, he chose to rectify the machine’s shortcomings and in the process, teach everyone a bunch of great tips.

[We Can Do That Better]’s lathe retrofit focused on the carriage handwheel, which appears to lack proper bearings and wobbles around in a most imprecise manner. On top of that, the gearing of the drive made for an unsatisfying 19 mm of carriage travel per revolution of the handwheel. A single gear change made that an even 20 mm per rev, which when coupled with a calibrated and indexed handwheel ring greatly simplifies carriage travel measurements.

While the end result of the build is pretty great in its own right, for our money the best part of the video is its rich collection of machinist’s tips. The use of a wooden dowel and a printed paper template to stand in for a proper dividing head was brilliant, as was using the tailstock of the lathe to drive an engraving tool to cut the index lines. We’ve seen the use of a Dremel tool mounted to the toolpost to stand in for a milling machine before, but it’s always nice to see that trick used. And the mechanism for locking the dial to the handwheel was really clever, too.

Considering a mini-lathe? As encouraging as [We Can Do That Better]’s experience may be, it might be wise to take a deep dive into the pros and cons of such a machine.

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Big homemade lathe

Heavy Metal Lathe Build Doesn’t Spare The Steel

October 27, 2021 by 22 Comments

It’s common wisdom that the lathe is the essential machine tool, and the only one that can make copies of itself. While we won’t argue the primacy of the lathe in the machine shop, this scratch-built, heavy-duty lathe gives the lie to the latter argument — almost.

We’re used to seeing homebrew lathes, of course, and we’ve featured more than a few of them before. But two things make [Jornt]’s build stand out: how few specialized tools were needed to build it, and the sheer size and bulk of the finished product. Where most homebrew lathes tend to be the bench top variety and feature cast aluminum parts, [Jornt] went with steel for his build, and a lot of it. The base and bed of the machine are welded from scrap steel I-beams, and the ways are made from angle iron that has been ground flat with a clever jig to hold an angle grinder. The angle grinder plays a prominent role in the build, as do simple tools like a hand drill, files, and a welder — and yes, the unfinished lathe itself, which was used to bore out the bearing blocks for the headstock.

The completed lathe, powered by a treadmill motor in a way that [Jeremy Fielding] would no doubt endorse, comes in at a beefy 450 kg. It honestly looks like something you could buy from a catalog, and has most of the features of commercial machines. One thing we’d love to see on this lathe is the electronic lead screw that [James Clough] developed for his off-the-shelf lathe.

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Vertical Mill Completes Scrapyard Lathe Build

January 12, 2021 by 12 Comments

One thing’s for sure: after seeing [Roland Van Roy] build a vertical mill from industrial scrap, we’ve got to find a better quality industrial scrapyard to hang around.

The story of this build started, as many good shop stories do, at the lathe, which in this case was also a scrapyard build that we somehow managed to miss when it first posted. This lathe is decidedly different from the common “Gingery method” we’ve seen a few times, which relies on aluminum castings. Instead, [Roland] built his machine from plate stock, linear slides, and various cast-off bits of industrial machines.

To make his lathe yet more useful, [Roland] undertook this build, which consists of a gantry mounted over the bed of the lathe. The carriage translates left and right along the bed while the spindle, whose axis lines up perfectly with the center axis of the lathe, moves up and down. [Roland] added a platform and a clever vise to the lathe carriage; the lathe tool post and the tailstock are removed to make room for these mods, but can be added back quickly when needed. Digital calipers stand in for digital read-outs (DROs), with custom software running on a Picaxe and a homebrew controller taking care of spindle speed control.

[Roland] reports that the machine, weighing in at about 100 kg, exhibits a fair amount of vibration, which limits him to lighter cuts and softer materials. But it’s still an impressive build, and what really grabbed us was the wealth of tips and tricks we picked up. [Roland] used a ton of interesting methods to make sure everything stayed neat and square, such as the special jig he built for drilling holes in the T-slot extrusions to the use of cyanoacrylate glue for temporary fixturing.

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Gorgeous Mini-Lathe Makes The Most Out Of Wood And Metal

November 16, 2020 by 32 Comments

It’s a cliche that the only machine tool that can make copies of itself is the lathe. It’s not exactly true, but it’s a useful adage in that it points out that the ability to make big round things into smaller round things, and to make unround things into round things, is a critical process in so many precision operations. That said, making a lathe primarily out of wood presents some unique challenges in the precision department

This isn’t [Uri Tuchman]’s first foray into lathe-building. Readers may recall the quirky creator’s hybrid treadle-powered and electric lathe, also primarily an exercise in woodworking. That lathe has seen plenty of use in [Uri]’s projects, turning both wood and metal stock into parts for his builds. It wasn’t really optimal for traditional metal turning, though, so Mini-Lathe 2 was undertaken. While the bed, headstock, and tailstock “castings” are wood — gorgeously hand-detailed and finished, of course — the important bits, like the linear slides for the carriage and the bearings in the headstock, are all metal. There’s a cross-slide, a quick-change tool post, and a manual lead screw for the carriage. We love the finely detailed brass handcranks, which were made on the old lathe, and all of the lovely details [Uri] always builds into his projects.

Sadly, at the end of the video below we see that the lathe suffers from a fair amount of chatter when turning brass. That’s probably not unexpected — there’s not much substitute for sheer mass whenit comes to dampening vibration. We expect that [Uri] will be making improvements to the lathe in the coming months — he’s not exactly one to leave a job unfinished.

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