Parts
Outer Gimbal Ring
Outer Gimbal Ring
This is the shell, structure, and outermost element of the gimbal. It does not move relative to the rocket body, and has one servo motor mounted in it which controls one axis of rotation. The pin holes at the bottom of the part have steel pins that run into the inner gimbal ring for servo motor control of the entire inner ring. For simplicity, the outer gimbal ring friction fits into the rocket body tube. This makes assembling and disassembling the gimbal easy, and makes the process of securing the gimbal in the body tube very consistent.
This is the shell, structure, and outermost element of the gimbal. It does not move relative to the rocket body, and has one servo motor mounted in it which controls one axis of rotation. The pin holes at the bottom of the part have steel pins that run into the inner gimbal ring for servo motor control of the entire inner ring. For simplicity, the outer gimbal ring friction fits into the rocket body tube. This makes assembling and disassembling the gimbal easy, and makes the process of securing the gimbal in the body tube very consistent.
Inner Gimbal Ring
Inner Gimbal Ring
As stated above, the inner gimbal ring is controlled by the servo motor mounted in the outer gimbal ring. As seen in the picture to the left, there is one central hole which holds a steel pin that is attached to the engine mount. There is another servo motor mounted in the inner ring, which is responsible for the axis of rotation perpendicular to the axis in which the inner ring is mounted to the outer ring. The two side holes, which hold the steel pins mounted to the outer ring, are positioned below the center of mass of the ring to decrease the moment of inertia of the ring about this axis, making quicker gimbal maneuvers possible.
As stated above, the inner gimbal ring is controlled by the servo motor mounted in the outer gimbal ring. As seen in the picture to the left, there is one central hole which holds a steel pin that is attached to the engine mount. There is another servo motor mounted in the inner ring, which is responsible for the axis of rotation perpendicular to the axis in which the inner ring is mounted to the outer ring. The two side holes, which hold the steel pins mounted to the outer ring, are positioned below the center of mass of the ring to decrease the moment of inertia of the ring about this axis, making quicker gimbal maneuvers possible.
Engine Mount
Engine Mount
This is the holster for solid rocket engines with an outer diameter of 29 millimeters. This allows up to "F" class motors, which can provide 80 Newton seconds of total impulse. The engine mount is supported by one steel pin at the top of the part, allowing rotation on the axis of this pin. On the side of the mount, there is a hole for the inner ring pushrod to be put through for servo motor control.
This is the holster for solid rocket engines with an outer diameter of 29 millimeters. This allows up to "F" class motors, which can provide 80 Newton seconds of total impulse. The engine mount is supported by one steel pin at the top of the part, allowing rotation on the axis of this pin. On the side of the mount, there is a hole for the inner ring pushrod to be put through for servo motor control.
Servo Motors and Pins
Servo Motors and Pins
12g servo motors, steel pushrods, steel pins, and nylon spacers are all purchased from McMaster-Carr and are used in both the first and second version of the gimbal. The servo motors are controlled through pulse width modulation with a PCB designed by Reusable Rocketry at Purdue's electronics team. In version 2 of the gimbal, the servo motors are able to perform maximum gimbal deflection (-12.5 to 12.5 degrees in any axis) in under 0.1 seconds.
12g servo motors, steel pushrods, steel pins, and nylon spacers are all purchased from McMaster-Carr and are used in both the first and second version of the gimbal. The servo motors are controlled through pulse width modulation with a PCB designed by Reusable Rocketry at Purdue's electronics team. In version 2 of the gimbal, the servo motors are able to perform maximum gimbal deflection (-12.5 to 12.5 degrees in any axis) in under 0.1 seconds.