When learning about the design of a machine or mechanism, reading and watching videos is certainly effective, but it’s hard to beat hands-on experimentation. In the video after the break, [Brick Technology] uses LEGO to gain some practical insight into the world of piston engine design, from single-cylinder all the way up to radial twelve-cylinder engines.
Using pneumatic cylinders from the LEGO Technic series, [Brick Technology] starts by getting the basics working with a single-cylinder design. Besides the fact that there are no fuel-air explosions involved, these pistons are also double-acting thanks to a valve mechanism that switches the pressurized side of the piston as it reaches the end of its stroke. After a couple of experiments, he settles on using a bank of six two liter soda bottles as a source of pressurized air.
He also increased the performance of the LEGO cylinders by drilling out the ports and adding silicon oil for lubrication. In the initial prototypes, the cylinders also acted as connecting rods, tilting back and forth as the crankshaft rotates. After some testing, he discovered he could increase efficiency by constraining the cylinder with a slider mechanism and adding a separate connecting rod.
With the basics done, [Brick Technology] could start experimenting with engine arrangements and geometry. Inline two, three, and four cylinders and V2, V6, V8, and even R12 were all on the menu. He could also change crankshaft geometry to trade torque for RPM and vice versa, and build a starter motor, and torque generator.
Just like [Brick Technology]’s LEGO electronic drums and vortex machine, this video gives us a itch that can only be scratched by a few hundred LEGO pieces. For rapid prototyping of course.
For a long time radial aircraft engines, with their distinctive cylinder housings arranged in a circle, were a common sight on aircraft. As an experiment, [KendinYap], wanted to see if he could combine 3 small DC motors into a usable RC aircraft motor, effectively creating an electric radial engine.
The assembly consists of three “180” type brushed DC motors, mounted radially in a 3D printed casing. A 3D printed conical gear is attached to each motor shaft, which drives a single output gear and shaft mounted in the center with two bearings. The gear ratio is 3:1. A variety of propellers can be mounted using 3D printed adaptors. As a baseline, [KendinYap] tested a single motor on a scale with a 4.25-inch propeller on a scale, which produced 170 g of thrust at 21500 RPM. Once integrated into the engine housing, the three motors produced 490 g of thrust at 5700 RPM, with a larger propeller. Three independent motors and propellers should theoretically provide 510 g of thrust, so there are some mechanical losses when combining 3 of them in a single assembly. However, it should still be capable of powering a small RC plane. It’s also not impossible that a different propeller could yield better results.
While there is no doubt that it’s no match for a brushless RC motor, testing random ideas just to see if it’s possible is usually fun and an excellent learning experience. We’ve seen some crazy flyable RC power plants, including a cordless drill, a squirrel-cage blower, and a leaf blower.
There’s something alluring about radial engines. The Wasps, the Cyclones, the Gnomes – the mechanical beauty of those classic aircraft engines can’t be denied. And even when a radial engine is powered by solenoids rather than internal combustion, it can still be a thing of beauty.
The solenoid engine proves that he has some mechanical chops. If you follow along in the videos below, you’ll see how [Tyler] progressed in his design and incorporated what he learned from the earliest breadboard stage to the nearly-complete engine. There’s an impressive amount of work here – looks like the octagonal housing was bent on a press brake, and the apparently homebrew solenoids are enclosed in copper pipe and fittings that [Tyler] took the time to bring to a fine polish. We’re skeptical that the microswitches that electrically commutate the engine will hold up to as many cycles are they’d need to handle for this to be a useful engine, but that’s hardly the point here. This one is all about the learning, and we think [Tyler] has done a bang-up job with that.
[Ian Jimmerson] has constructed a detailed model of a radial engine out of wood and MDF for an undisclosed reason. Rather than just delivering the wooden engine to wherever wood engines go, [Ian] decided to take the time to film himself disassembling and reassembling his engine, explaining in detail how it works as he goes. He starts by teaching about the cylinder numbering and the different possible cylinder configurations. It only gets better after that, and it’s worth watching the full 20 minutes of video. You’ll leave with a definite understanding of how radial engines work, and maybe build something neat with the knowledge.
Our only complaint is the lack of build photos or construction techniques. It’s a real feat to build something with this many moving parts that can run off an electric drill. Was a CNC involved, or was he one of those hardcore guys who manage to get precision parts with manual methods? Part 1 and 2 after the break.
Radial engines are just plain cool – it’s inarguable that any tech that originated with early aviation is inherently awesome. But, what do you do when you want to build a radial engine in your dorm where a combustion engine would be inadvisable? For University of Washington students [Jeffrey Weng] and [Connor Lee] the answer was to power it with solenoids in place of the pistons.
The easiest way to approach a project like this would have been to use a microcontroller. A simple program running on an Arduino could have easily provided the timing to switch power to each solenoid in succession. [Jeffrey Weng] and [Connor Lee], however, took a much more interesting approach by controlling timing via a simple distributor. This works in the same way a spark distributor on a combustion engine would have worked, except it’s actually providing the power to actuate the solenoids instead of providing just an ignition spark.
Also impressive is what they were able to accomplish with such basic tools. Those of us who are lazy and have access to more expensive tools would have just 3D printed or CNC cut most of the parts. Either [Jeffrey Weng] and [Connor Lee] didn’t have access to these, or they wanted to increase their machining street cred, because they created all of the parts with simple tools like a band saw and drill press. We’ve seen some beautiful engine projects before, but what this build lacks in objective beauty it makes up for in ingenuity.
Russians blowing up capacitors! As we all know, electronics only work because of blue smoke. [kreosan] is releasing this blue smoke from a few hundred caps. Fun times, even if they are a large number of inert tube shields in their collection of caps.
[Richard] wanted a Minecraft server, but not just any Minecraft server; this one demanded a custom case. A grass block was the inspiration, acrylic the medium, and a quad-core Mini-ITX the guts of the project.
[Matthias Wandel], a.k.a. the woodgears.ca dude, is well-known in certain circles for being a wizard of wood. One of the first projects that put him on the map was a pantorouter – a router to cut mortises and tenons. He’s going back to his roots and building a bigger version. This version uses models of routers that are available outside North America, and in the latest video [Matthias] has it dialed in very well.
There’s little more information on this hack, however, it’s quite interesting seeing an automated drum and a scanner playing a familiar Christmas tune. Check out the video of the duet in action!
A Radial Engine Model:
Through the process of experimentation, two “radial engine models” were produced. The engine model shown above uses a gear-reduced motor to power it. The other model uses CNC-cut gears and a motor from an air freshener!
Tips and Tricks on Repairing LCD Monitors:
So do you have a broken LCD monitor? Using techniques described in his post, [Neoxity] claims to have been able to repair 50 out of 60 broken monitors using techniques described on his blog.
While we’re on the subject of [Neoxity’s] page, why not check out his discussion on “flex cables” used for DIY. Like the humble resistor, they’re not glamorous, but you’d be hard pressed to find an electronics assembly without one.
Although not a hack in itself, the “illegal number” is a really interesting concept (mentioned by one of our readers in the comments). Since all data and programs can, at their core, be represented by a series of 1s and 0s, this can also be interpreted as a number. Thus, some numbers actually represent copyrighted or trade secret data that would be illegal to possess.