A simple device for carrying a wide sheet materials are easy to make yourself, having at hand two, tee, four corners and three or four water pipe section.
Recommend to read
THE TIMER CONTROLS THE SOUND
The device, whose scheme is published in the journal "Popular electronics" (USA), produces a positive pulse when a sound (for example, firing of the gun) reaches the microphone B1 (see...
AND AGAIN NUTRIT
On the mechanisms used to its movement due to inertia of the rotating imbalances of the journal "modelist-Konstruktor" wrote more than once (see number 5 and 12 for 1975, No. 6 1976, No....
