Cristiano Maker

There is an amazing device to do exercises at home named "Power Twister" or "Power Crusher". I used it since my 10 years old. Below, there are some pictures with good exercises to do with it. The guide is in Portuguese but the images tell by themselves.

In my opinion, the Republic P-47 Thunderbolt is one of the most amazing planes of WWII. Some time ago, I found some interesting videos on Youtube showing how to fly this plane:

This is my homemade vacuum forming machine first try. I want to make a metal detector coil housing but I failed at the first time. May be due to using a too thick plastic (2mm polystyrene) or not enough temperature. The vacuum is obtained from a small vacuum cleaner (1400W) Here are some pictures of the device and a video. Next time I will try with a thinner plastic or other type (ABS). Part 2 - After some fails, the success! Well, today I will talk about the second try. I'm using the same type of plastic - polystyrene, 2mm but now I have a thermometer so I can measure it's temperature. I also added some screws to the frame, so I can prevent the plastic sheet from moving with the heat (because of expansion / contraction) and finally I got a good result as you can see below: I kept the plastic in the oven until it reached about 150 degrees celsius at the center of the sheet. Almost perfect. Not 100% because it seems I moved slightly the form out of place and it is not centered. ...

Some days ago, I was on the internet searching for old amateur radio projects and I've found a website that contains a lot of old magazines (  https://worldradiohistory.com/Archive-Short-Wave-Television/30s/ ) with exactly what I wanted - the only problem was they are so many, that I was no patience to download one by one, so, I decided to use some of my programming skills to help me, by making a simple python webscraping script, using the BeautifulSoup library. If you want to learn how I did it, please check my YouTube video below:

 Today, I made a simple video demonstrating how the control grid of a vacuum tube triode may work. Essentially, the purpose of a control grid, is to control the flow of electrons from the cathode to the anode of a vacuum tube. So, im my experiment, I put my ammeter in series with the B+ and the tube plate and applied a positive charge from a 9v battery and then I inverted the battery polarity, applying a negative charge. In the first case, It is possible to see the current flow increasing, while in the second case, the current practically doesn't flow anymore. You can see this simple experiment in the YouTube video below: For this experiment I used an early type 30 tube, a 1.5v battery and a 90v stack of 10 * 9v batteries and a couple of wires. Hope you like!

 I live in an old house that has no grounding system. As I do many projects using considerable voltages, like vacuum tube amplifiers, I need at least a grounded wall socket for my own security and the security of my devices. So, as my house is rented, I don't want to request someone to make a full/proper ground installation for the entire house. Instead, I created my own grounded socket. Fortunately, the house as a backyard, so I bought a copper grounding rod and buried it into the backyard and then I took a thick wire from it to the inside of the house and made a connection to the ground pin of a "female" socket and I'm using it for my projects. Below, there is a simple video showing the efficiency of that system I made: You you have a similar situation as mine, you can do something similar.

 Maybe you don't know, but you can use a car wiper motor to power your low speed / high torque project. For example, I used this kind of motor to power a ball mill I made some time ago. All you need is a used wiper motor, a computer ATX power supply and 2 wires. The first step is to find what is the low speed connection of your motor. Usually, it is a connection labelled with "53". If you can't find this in your motor, please take a search on the Internet about that for your specific motor brand / model (you can search also by the vehicle brand and model from which you got the motor). Then, as the 12volt supply, we will use any yellow wire from the power supply, and for the negative (ground) you may use any black one. Is simple as that, just connect a yellow from the power supply to the low speed connection of the motor (53 code) and the black wire to the ground connection (this could be simply the any metallic part of the motor). Please take also a look the the YouTu...