Tandem — A Bicycle for Two

Homemade tandem bicycle: frame and drive

For many years I have been a regular subscriber to “M-K” and find in it a great deal that is interesting and useful. I hope my experience will also be of use to other readers: I want to share my thoughts and practical recommendations on making and operating a tandem bicycle. I built such a Read more…

Autogyro Rotor

Autogyro rotor blades: manufacture, balance, hub assembly

It is no exaggeration to say that the most important part of a glider-autogyro is the rotor. The autogyro’s flight qualities depend on the correctness of its airfoil, on mass, centering accuracy, and strength. True, the unpowered craft on a car tow rises only to 20–30 m. But even flight at such a height requires Read more…

A Sauna for Bees

Thermal unit for treating bees against mites

For almost twenty years, a design club for agricultural modeling has been operating at the Chernihiv regional Station of Young Technicians. Over the years, the students, under the guidance of their mentors, have developed and built many useful machines, mechanisms, and devices, many of which are of practical economic importance and bring real benefit to Read more…

Electric Cycle

DIY electric motorcycle: design, wiring, and road tests

Ecology and environmental protection are becoming increasingly relevant topics worldwide. Requirements for harmful emissions from vehicles are constantly being tightened. That is why major manufacturers are developing and starting to produce electric and hybrid cars. These trends are also reaching our country. And while the evolutionary direction of automotive development has been defined and is Read more…

Pedals for Champions

Bike drive with automatically extending pedal levers

The bicycle is probably the most widespread means of transport. And there is no doubt that it is also the most economical: two buttered sandwiches are enough to pedal for two hours. But can the efficiency of the human “engine” be increased? Reducing “fuel” consumption will not help. Friction and the weight of the machine Read more…

Around the Nail

18 tips: how to drive nails the right way

It would seem that driving a nail is about as simple as it gets. Still, even this seemingly straightforward operation requires a calculated approach and some experience. 1. Long nails are best driven with a 400—500 g hammer, and small ones with a hammer weighing up to 250 g. 2. To find nails driven deep Read more…

A ‘Hair Dryer’ for Welding

DIY hot-air gun for plastic welding at home

I offer home craftsmen (and not only them) a tool for welding plastics. However, it can also be used for a wide range of technical creativity tasks — for example, to blow solder off dismantled electronic boards. After all, the temperature of the air coming out of the nozzle tube will reach 300°C, and it Read more…

A Test for the House

Plot layout rules and dwelling house requirements

On his own land, the owner erected a two-storey shell of a “Canadian” house on a strip foundation. The adjacent plot had long been for sale. At last it found a new owner, who invited a surveyor for an accurate layout of the plot. During that procedure it turned out that the neighbour had built Read more…