When there are no guns, no shotguns, no revolvers. People fought with spears, swords, and just rocks. In ancient times during the siege of fortresses used a special weapon for throwing large stones, catapult. In these simple military machines were used “energy” twisted ropes made of sinews.
HOW TO SAVE THE THREAD
It is useless to try to saw off the screw with a hacksaw: broken thread, the nut cannot be screwed on the warped teeth first turns. But the same operation will be quite successful if you screwed the nut on the screw: then at screwing its threads, the threads will be straightened.
The attention of many modelers are attracted to the photos (“M-K”, No. 10, 1979) on the international competition teams of the socialist countries on aviamodelling sports. The editors have received many letters with the request to give more details about the model of the winner of these competitions the master of sports of international class Anatoly Kolesnikov from Frunze. To fulfill these wishes. L. Kolesnikov talks about his Cordoba flight.
Every year fewer and fewer aircraft with piston engines. Lightweight, economical running on cheaper than gasoline, fuels, jet engines replacing piston even from agricultural aviation. But in any aeromodelling competition still reigns “piston era”. On kartodromo you will see the masterfully made copies of “Ilya Muromets”, “Nieuport”, I-15, Yak-3… do Not attempt to only search for a model jet aircraft — the era of rapid modern machines in modeling has not yet arrived. The reason is the lack of jet motors or at least their imitators: piston motors with impellers. Unfortunately, numerous attempts by modelers to create quasirational the engine was not successful — usually these devices have extremely low efficiency and did not develop the thrust required for steady flight of the model.
Jigsaw is perhaps the most popular tool in the home workshop craftsmen, and in the laboratory modeller. Meanwhile, its design has remained unchanged for decades, but this does not mean that it is perfect.
With all its advantages of an inflatable boat of any design has the same General disadvantages: Shorty wislica, turtle speed and bad handling. From all of them at once we managed to get rid of, adapting your boat “Dive-4” under sail: with him she became and the faster and more manageable. And actually upgrading was quite simple and compact, that is blended with the amenities characteristic of inflatable boats.
My tools are designed for processing of soil in the garden and the vegetable garden. The main type of work in the spring and summer — preparation of beds for planting and care of plants. Therefore, more than a third of the set are rippers. They are divided into three types: one-, two – and trehrozhkovye, and each is used depending on the planting density and the soil conditions. Where gaps between plants are great, easy to work trehrozhkovye — they are the most productive; and where planting is thickened, handy slowly loosen the ground two or odnokrylym.