Metal lathes are capable machines that played a large role in the industrial revolution, and an incredible tool to have at your disposal. But that doesn’t mean they can’t be used to have a little fun, as demonstrated by [Oleg Pevtsov] who made a bidirectional bolt as a machining exercise just because he could.
Both videos after the break are in Russian, but the video and auto generated subtitles are enough to get the main points across. The bolt is an M42 size with a 40 mm pitch, with grooves cut in both directions to allow left-handed and right-handed nuts to be threaded. The large pitch means that instead of a single continuous groove like a normal bolt, ten separate grooves need to be cut for each threading direction to cover the bolt surface. Since this was all machined on a manual lathe, a dial indicator was required to maintain accurate spacing. It took [Oleg] four painstaking attempts to get it right, but the end result looks very good. Instead of a fixed cutter, he used a trimming router mounted on a custom clamp.
[Oleg] also machined three different brass nuts to go on the bolt with a fixed cutter. First left-hand and right hand threaded nuts were made, followed by a bidirectional nut. Due to the large pitch and careful machining, all three nuts will spin down the bolt under the force of gravity alone. Although the bidirectional nut doesn’t move as smoothly as the other two, it can change rotation and translation direction at random.
While this is a one-of-a-kind fidget toy, have any of our readers seen a bidirectional bolt or lead screw in the wild? We can imagine that the ability to move two nuts in opposite directions on a single lead screw might have some practical applications.
It’s possible to make incredible parts on a manual lathe. A handbuilt V10 engine and a pneumatic hexacopter model are just two examples of what’s possible with enough skill, knowledge, and patience. Sadly it is a fading form of craftsmanship, rendered mostly obsolete outside of hobby projects by CNC machines.
Continue reading “Tighten This Bolt In Any Direction You Want” →
Eric Weinhoffer has had plenty of experience in the product design arena, and this hard-earned knowledge is readily apparent in his mentor session for The Hackaday Prize. These serve to link up Prize entrants with industry experts in order to help them take their projects into production. You still have time to get in on the 2019 Hackaday Prize which is accepting entries until August 25th.
Eric’s work as a Prototype Engineer at Bolt stands him in good stead to deliver valuable advice on manufacturing techniques and prototyping. With projects as diverse as CNC milling machiness and ISS payloads under his belt, Eric was able to help out these entrants with a series of tricky problems that will be familiar to anyone who has tried to take a project out of the lab and into the market.
Let’s take a look at the projects and the advice that were shared during this session.
Continue reading “Eric Weinhoffer Covers Enclosure Design And Manufacturing Tech During Hackaday Prize Mentor Session” →
They hold together everything from the most delicate watch to the largest bridge. The world is literally kept from coming apart by screws and bolts, and yet we don’t often give a thought to these mechanisms. Part of that is probably because we’ve gotten so good at making them that they’re seen as cheap commodities, but the physics and engineering behind the screw thread is interesting stuff.
We all likely remember an early science lesson wherein the basic building blocks of all mechanisms laid out. The simple machines are mechanisms that use an applied force to do work, such as the inclined plane, the lever, and the pulley. For instance, an inclined plane, in the form of a splitting wedge, directs the force of blows against its flat face into a chunk of wood, forcing the wood apart.
Screw threads are another simple machine, and can be thought of as a long, gently sloped inclined plane wrapped around a cylinder. Cut a long right triangle out of paper, wrap it around a pencil starting at the big end, and the hypotenuse forms a helical ramp that looks just like a thread. Of course, for a screw thread to do any work, it has to project out more than the thickness of a piece of paper, and the shape of the projection determines the mechanical properties of the screw.
Continue reading “Mechanisms: The Screw Thread” →
Becoming accomplished with a lathe is a powerful skillset, but it’s only half of the journey. Being clever comes later, and it’s the second part of the course. Patience is in there somewhere too, but let’s focus on being clever. [TimNummy] wants a knobbed bolt with critical parameters, so he makes his own. After the break, there is a sixty-second summary of the linked video.
Making stock hardware is a beginner’s tasks, so custom hardware requires ingenuity or expensive machinery. Adding finger notches to a bolthead is arbitrary with an indexing chuck, but one isn’t available. Instead, hex stock becomes a jig, and the flat sides are utilized to hold the workpiece at six intermittent angles. We can’t argue with the results which look like a part that would cost a pretty penny.
Using material found in the workshop is what being clever is all about. Hex brass stock comes with tight tolerances on the sides and angles so why not take advantage of that?
[TimNummy] can be seen on HaD for his Jeep dome light hack and an over-engineered mailbox flag. Did you miss [Quinn Dunki]’s piece on bootstrapping precision machine tools? Go check that out!
Continue reading “Indexing Chuck Not Required” →
Here’s a great way to quickly and easily make attractive and functional knobs with no tools required. All you need is some casting resin (epoxy would do in a pinch), a silicone mold intended for candy, and some socket head bolts. With the right preparation and a bit of careful placement and attention, smooth and functional knob ends are only minutes away. Embedded below is a short video demonstrating the process.
These may not replace purpose-made knobs for final products, but for prototypes or to use around the shop on jigs, clamps, or furniture they certainly fit the bill. With a layer of adhesive fabric or rubber, they might even make serviceable adjustable feet for low-stress loads.
This technique could be extended to reproducing broken or missing dakaware or bakelite knobs. This, of course, would require an original, unbroken knob and a small silicone mold, but it’s still a project that’s well within the capabilities of the garage-bound hacker.
While we’re on the subject of knobs, don’t forget we’ve seen an excellent method of repairing knobs as well.
Continue reading “A Great Way To Make Quick And Easy Knobs” →
Ben Einstein, a product designer and founder at Bolt, a hardware-based VC, recently got his hands on a Juicero press. This desktop juice press that only works with proprietary pouches filled with chopped fruits and vegetables is currently bandied in the tech press as evidence Silicon Valley has gone mad, there is no future in building hardware, and the Internet of Things is a pox on civilization. Hey, at least they got the last one right.
This iFixit-style tear down digs into the Juicero mixer in all its gory details. It’s beautiful, it’s a marvel of technology, and given the engineering that went into this machine, it was doomed to fail. Not because it didn’t accomplish the task at hand, but because it does so with a level of engineering overkill that’s delightful to look at but devastating to the production cost.
Continue reading “Juicero: A Lesson On When To Engineer Less” →
You’ve got to enjoy any project where the hacker clearly loves what he or she is doing. And when the project is as cool as a motor-driven, rubber band powered, fully automatic crossbow, it’s hard not to laugh along.
A full-auto crossbow is no mean feat, and it took a man with a love for rubber-powered firearms to get it right. [JoergSprave]’s design is based on a rack-and-pinion system and executed mainly in plywood. The main pinion gear is a composite of aluminum and wood, in a bid to increase the life of the mechanism and to properly deal with the forces involved. The pinion, turned by a powerful electric drill, drives the rack back and locks the carrier under the 30-bolt magazine. A rubber-powered follower forces a bolt down and a cam on the pinion trips the sear, the bolt is fired and the cycle continues.
We slowed the video down a bit and it looked to us like the cyclical rate of fire was about 7 rounds per second, or a respectable 420 rounds per minute. Pretty powerful, too, and the accuracy isn’t bad either.
We’ve seen [Joerg]’s inventions before, like this soda bottle Gatling arrow launcher, or his ridiculous machete launcher. We hope he keeps having fun and letting us watch.
Continue reading “Full-Auto Crossbow Rocks And Rolls On Rubber Bands And Electric Drill” →