It is well know that the ignition of a KNO3-sorbitol motor is sometimes a challenge. It happens that only a small surface of the motor gets ignited, expecially the top and bottom surfaces of the different segments of a Bates burner. When this happens when launching a rocket with a KNO3-sorbitol motor, it can results in dangerous stability situations.

To resolve this a series of tests were executed wih an igniter existing of a long tube (2m lenght by 1cm diameter) foreseen of many small holes of 1mm. The tubes was filled with Zinc-Sulfer powder (ratio 3/1).

We can see during these test that the tube get already fully ignited over his 2m length after 0.2s.

An analog system but smaller in lenght was successfully used to ignite the KNSB58-2 motor.

Figuur 1: igniter