Ever used magnets in a project, and had to fiddle around with it until it worked? Then you should have used a magnetic viewing film, so you could see the problem directly.
With a magnetometer you can detect the existence and location of a magnet several inches away, perfect for so many robotic projects. You can even use it as a non-contact joystick as demonstrated it the video below this one:
We all uses DC motors in one way or another. Even if you’re not building a machine that have DC motors, you still engage them when you use a machine to brush your teeth, shave your hair or get a buzzing sound from your mobile phone. But do you know how they work? Just check this video from Learn Engineering and see if you actually know all the detailed science that goes into making a modern DC motor.
Electric motors come in many size and types, but the homopolar motor is without a doubt the simplest motor in the world. While the efficiency and torque is lower compared to ordinary motors, the ease of construction and small size makes it a very interesting build and a possible perfect fit for small-scale mechanics. All you need is a battery, neodymium magnet and copper wire, that’s it! In this video from Nicole Zavi a normal double A battery is used, but there is not reason why a button cell can’t be used instead and result in a motor that only measure a couple of millimeters in width and height. This video is the best we have found so far, since it not only shows many variations of wire design and how to use it for a practical purpose, but also the importance of adjusting the tightness of the wire and balancing it on the battery. To make it easier to balance it, we recommend making a small dimple on the top of the battery with any metal tool, like a screwdriver. We believe that this type of motor has more potential then it has gotten credit for in the past, and we would love to see how you use this in your project, so be sure to send us your homopolar pictures or videos!
Do you have a computer model that you want to realize or just want to replicate an existing object? Don´t need it to have mechanical functions? No access to a 3D printer and would rather avoid the messy work of Papier-mâché? Then this video is for you! Here Will and Norm from Tested demonstrates how a program called “Pepakura“, a printer and some glue can allow you to realize that computer model for cheap and without fancy equipment.