Monday, February 14, 2011

Video lessons – rapid fire pistol shooting basics by Khaidurov

Two video lessons by Efim Khaidurov. Absolute rarity and exclusive. These videos were produced by Soviet Union’s ministry of sport in 1982-1983.
I promise to add annotations in English as soon as possible – so you can understand what is right and what is wrong.

Pistol shooting basics (with annotations in English)

Rapid fire pistol shooting basics (with annotations in English)

Wednesday, February 9, 2011

TOZ-35 free pistol with electromechanical trigger

New project: electromechanical trigger for TOZ-35 free pistol.
Our goals:
  • Get rid of many tiny parts of mechanical trigger no more available today on the market;
  • Learn – how electromechanical trigger might work;
  • Original pistol weight and balance must remain the same as before;
  • Learn something new.
Electromechanical trigger consists of two main parts:
  • Electronic part. Subdivided into:
    • Power supply (rechargeable via USB);
    • Contact key (button, switch, pressure gauge etc);
    • Analog amplifier;
    • Digital converter;
    • Digital analyzer;
    • Impulse generator;
    • Solenoid.
  • Mechanical part – original bolt «as is».
Developers: me and Alexander Exl.

Sun, 13 Feb 2011:
We worked all day on strain gauge, Wheatstone Bridge and Instrumentation amplifier. Seems to be work. Photos a little bit later.
As you may notice – we use strain gauge – no buttons, no springs, no contacts, no trigger movement. Later it must be enough to tune tiny potentiometer to adjust the «trigger weight».

Wed, 23 Feb 2011:
Amplifier with the gain of 10000 in action.

Sat, 26 Feb 2011:
Noise immune threshold circuit has only two states - low and high.

Sun, 6 March 2011:
Trigger hysteresis switching and pull force measured in Volts.