It’s not news that Leonardo DaVinci was somewhat ahead of his time, and over the centuries many of the creations in his sketchbooks have been created and proved quite functional. The guys from the YouTube channel How To Make Everything have been looking at one such sketch, a screw thread-cutting machine. At first glance, it seems a little flawed. Threads are hard to make by hand, and you can see that this thread-cutting machine needs two identical threads operating as a reference to make it work. However, as the guys demonstrate, you can create threads by hand using simple methods.
Starting with an offset blade mounted on a block with a hole through it, a dowel can be scribed with a starter thread. This can then be worked by hand to cut enough of a groove for the application. They demonstrated that the machine was viable using nothing but wood for construction. A metal blade was mounted, and some preload force was applied to it with a spring. The dowel to be cut was loaded, and the machine ran back and forth enough times to create a very nice-looking screw thread. And once you’ve made two identical threaded dowels, you can use them to upgrade the machine or even build a second. Once you have a repeatable way to make such threads, all kinds of applications become more accessible. Need a bench vice? No problem now!
Whilst the demonstration doesn’t precisely follow the plans laid out by the master inventor, they aren’t all that clear on the cutting tool after all, it’s nice to see people still wanting to build his ideas, and we’ll certainly be following along.
If you like these “from scratch” builds, you’ll like this other one. Leonardo’s work wasn’t just about machines; he was also very interested in science. Here’s a recreation of his demonstration of gravity as a form of acceleration.
Thanks to [Keith] for the tip!
Next do the transmission gearing in his “tank” vehicle design.
(I suspect that was an innocent oversight on his part, he’s clearly smart enough to recognize that three gears all meshed together is a brick)
I’ve heard suggestions that he did it deliberately, as a means of limiting his era’s arms race.
The drawing shows a wooden plane blade embedded in the traveling block cutting the screw profile
The impressive idea of this is that this will make screws more accurate than the ones used in the device. Errors will average out.
I would love to see this used over and over. True to HTME, with a water wheel, turning two new screws and using them in the machine to make another two and so on. Or maybe with an electric motor going back and forth?
At some point you could use a finer cutting device. Harder wood to be cut?
If you are patient, how far can this go?
In about 500 years of device evolution you could be making nanometer-scale features on silicon disks! Imagine what you could do with that!