Homemade Gear Cutting Indexer Blends Art With Engineering

October 10, 2020 by Adam Zeloof 23 Comments

Ordinarily, when we need gears, we pop open a McMaster catalog or head to the KHK website. Some of the more adventurous may even laser cut or 3D print them. But what about machining them yourself?

[Uri Tuchman] set out to do just that. Of course, cutting your own gears isn’t any fun if you didn’t also build the machine that does the cutting, right? And let’s be honest, what’s the point of making the machine in the first place if it doesn’t double as a work of art?

[Uri’s] machine, made from brass and wood, is simple in its premise. It is placed adjacent to a gear cutter, a spinning tool that cuts the correct involute profile that constitutes a gear tooth. The gear-to-be is mounted in the center, atop a hole-filled plate called the dividing plate. The dividing plate can be rotated about its center and translated along linear stages, and a pin drops into each hole on the plate as it moves to index the location of each gear tooth and lock the machine for cutting.

The most impressive part [Uri’s] machine is that it was made almost entirely with hand tools. The most advanced piece of equipment he used in the build is a lathe, and even for those operations he hand-held the cutting tool. The result is an elegant mechanism as beautiful as it is functional — one that would look at home on a workbench in the late 19th century.

[Thanks BaldPower]

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Custom Tool Helps Hakko Set Threaded Inserts

October 5, 2020 by Dan Maloney 10 Comments

When the tool you need doesn’t exist, you have to make it yourself. Come to think of it, even if the tool exists, it’s often way more fun to make it yourself. The former situation, though, is one that [Sean Hodgins] found himself in with regard to threaded inserts. Rather than suffer from the wrong tool for the job, he machined his own custom threaded insert tool for his Hakko soldering iron.

Like many of us, [Sean] has embraced the use of heat-set threaded inserts to beef up the mechanical connections on his 3D-printed parts. [Sean] dedicated a soldering iron to the task, equipping it with a tip especially for the job. But it was the flavor of iron proverbially known as a “fire stick” and he found that this iron was too hot for PLA prints. As the new owner of a lathe, he was able to make quick work of the job using a piece of brass rod stock. Luckily, Hakko tips just slip on the heating element, so no threading operations were needed. [Sean] made insert tips for multiple sized inserts, and the results speak for themselves.

If you haven’t tried these out yet, check out [Joshua Vasquez’s] excellent guide on heat-set inserts. You’ll find this guide to the relative merits of the different types useful when ordering inserts. And if you’ve got the itch to buy a lathe now, we’ve got you covered there too.

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Teaching An Old Lathe New Tricks With A Programmable Power Feed

October 4, 2020 by Adam Zeloof 17 Comments

Ask anybody whose spent time standing in front of a mill or lathe and they’ll tell you that some operations can get tedious. When you need to turn down a stainless rod by 1/4″ in 0.030″ increments, you get a lot of time to reflect on why you didn’t just buy the right size stock as you crank the wheel back and forth. That’s where the lead screw comes in — most lathes have a gear-driven lead screw that can be used to actuate the z-axis ( the one which travels parallel to the axis of rotation). It’s no CNC, but this type of gearing makes life easier and it’s been around for a long time.

[Tony Goacher] took this idea a few steps further when he created the Leadscrew Buddy. He coupled a beautiful 1949 Myford lathe with an Arduino, a stepper motor, and a handful of buttons to add some really useful capabilities to the antique machine. By decoupling the lead screw from the lathe’s gearbox and actuating it via a stepper motor, he achieved a much more granular variable feed speed.

If that’s not enough, [Tony] used a rotary encoder to display the cutting tool’s position on a home-built Digital Readout (DRO). The pièce de résistance is a “goto” command. Once [Tony] sets a home position, he can command the z-axis to travel to a set point at a given speed. Not only does this make turning easier, but it makes the process more repeatable and yields a smoother finish on the part.

These features may not seem so alien to those used to working with modern CNC lathes, but to the vast majority of us garage machinists, [Tony]’s implementation is an exciting look at how we can step up our turning game. It also fits nicely within the spectrum of lathe projects we’ve seen here at Hackaday- from the ultra low-tech to the ludicrously-precise.

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True Craftsmanship: Pneumatic Powered Drone Wasn’t Made To Fly

August 10, 2020 by Danie Conradie 16 Comments

From time to time it’s good to be reminded that mechanical engineering can also be art. [José Manuel Hermo Barreiro], also known as [Patelo], is a retired naval mechanic with a love for scale model engines. Using only basic tools and a lathe, he has built a non-flying hexacopter display model, each propeller turned by a tiny single cylinder motor that runs on compressed air. From the tiny components of the valve systems, the brass framed acrylic windows into the crankcases, and the persistence of vision disc on the exhaust, the attention to detail is breathtaking.

One of the six hand crafted pneumatic motors

[Patelo] started the project on paper, and created a set of detailed hand-drawn blueprints to work from. Sadly a large part of the build took place during lockdown, and was not filmed, but we still get to see some work on a crankcase, connecting rod, camshaft, propellers, flywheel, and exhaust tubes. It is very clear that [Patelo] knows his way around his lathe very well, and is very creative with custom tools and jigs. The beautiful machine took approximately 1,560 hours to build, consists of 265 individually made parts held together with 362 screws.

We previously featured tiny V-12 engine that [Patelo] built around 2012. At that time he was 72 years of age, which means he should be around 80 now. We can only hope to come to emulate him one day, and that we get to see more of what comes out of his workshop. Hats off to you, sir.

Turning A Waterjet Cutter Into A Wood Lathe, For No Reason

July 9, 2020 by Dan Maloney 30 Comments

On the shortlist of dream tools for most metalworkers is a waterjet cutter, a CNC tool that uses insanely high-pressure water mixed with abrasive grit to blast sheet metal into intricate shapes. On exactly nobody’s list is this attachment that turns a waterjet cutter into a lathe, and with good reason, as we’ll see.

This one comes to us by way of the Waterjet Channel, because of course there’s a channel dedicated to waterjet cutting. The idea is a riff on fixtures that allow a waterjet cutter (or a plasma cutter) to be used on tubes and other round stock. This fixture was thrown together from scrap and uses an electric drill to rotate a wood blank between centers on the bed of the waterjet, with the goal of carving a baseball bat by rotating the blank while the waterjet carves out the profile.

The first attempt, using an entirely inappropriate but easily cut blank of cedar, wasn’t great. The force of the water hitting the wood was enough to stall the drill; the remedy was to hog out as much material as possible from the blank before spinning up for the finish cut. That worked well enough to commit to an ash bat blank, which was much harder to cut but still worked well enough to make a decent bat.

Of course it makes zero sense to use a machine tool costing multiple hundreds of thousands of dollars to machine baseball bats, but it was a fun exercise. And it only shows how far we’ve come with lathes since the 18th-century frontier’s foot-powered version of the Queen of the Machine Shop.

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Build A Lathe Like It’s 1777

June 29, 2020 by Tom Nardi 22 Comments

We’ve seen quite a few scratch built lathes here at Hackaday, but none quite like the handcrafted pole lathe put together by [Jon Townsend] and his band of Merry Men as part of their effort to build a period-accurate 18th century log cabin homestead. With the exception of a few metal spikes here and there, everything is made out of lumber harvested from the forest around them.

The lathe is designed to be a permanent structure on the homestead, with two poles driven into the ground to serve as legs. Two rails, made of a split log, are then mounted between them. The movable components of the lathe, known as “puppets” in the parlance of the day, are cut so they fit tightly between the rails but can still be moved back and forth depending on the size of the work piece. With two metal spikes serving as a spindle, the log to be turned down is inserted between the puppets, and wedges are used to lock everything in place.

So that’s the easy part. But how do you spin it? The operator uses a foot pedal attached to a piece of rope that’s been wound around the log and attached to a slender pole cantilevered out over the lathe. By adjusting the length and angle of this pole, the user can set the amount of force it takes to depress the pedal. When the pedal is pushed down the log will spin one way, and when the pole pulls the pedal back up, it will spin the other.

Since the tools only cut in one direction, the user has to keep letting the pressure off when the log spins back around. The fact that the work piece isn’t continuously rotating in the same direction makes this very slow going, but of course, everything was just a bit slower back in the 18th century.

So now that we’ve seen lathes made from wood, intricately cut slabs of stone, and a grab bag of junkyard parts, there’s only one question left. Why do you still not have one?

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Turn By Wire Is A Machinist’s Sixth Sense

March 24, 2020 by Sonya Vasquez 14 Comments

It’s hard not to be a little intimidated by the squeaks and whirs that come with your first journey into a machine shop. Here, skilled machinists pilot giant hunks of cast iron that turn metals into piles of chips to yield beautiful parts. But what if machine tools themselves didn’t have to seem so scary. What if using them could feel a bit more intuitive, even, dare we say, natural from the get-go?

Enter Turn by Wire, a unique set of force feedback and machine control concepts applied to a lathe brought to you by researchers [Rundong Tian], [Vedant Saran], [Mareike Kritzler], [Florian Michahelles], and [Eric Paulos] at Berkelely.

Turn by Wire vastly reimagines the relationship between a user’s control inputs and the machine outputs in two ways: (1) by changing the mapping between the hand cranks and machine movements and (2) by changing the haptic feedback felt by the machinist. Since both of these interactions can be defined programmatically, the researchers created three unique ways of interacting with the lathe. First, by defining a tool path in the graphic user interface (GUI), the machinist can use a single hand crank to step forward and back in time along that toolpath. Second, by applying virtual guidelines in the GUI, both the machine and the hand cranks will physically snap to the guide lines when they are sufficiently close. Finally, the hand cranks can be used to teach the machinist a technique by adding resistive forces into the hand cranks depending on movement while a machinist is stepping through a process like peck drilling.

This is a great example of [Tom Knight’s] “just wrap a computer around it!” as mentioned by [Bunnie Huang] when we featured the IQ Motor Modules. It’s a powerful example of how putting a computer between the controls and the machine can correct for real world imperfections, be they in the mechanics of the machine of the operator. For the curious, have a look at [Rundong’s] paper published at UIST and [Vedant’s] master’s thesis.

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