Throttle Mechanism

Since the Odyssey engine is a hybrid, only one propellant will need to be throttled. For this, we have selected a Swagelok needle valve (SS-12NBF12) with a custom actuator mounted on top. The motor we chose was an ODrive DC motor (M8325S) with an integrated encoder.

We found the needle valve to be approximately 4.75 turns open to close. With this setup, we have demonstrated the ability to go from open to close within 0.5 seconds. The ODrive motor also allows us follow ramps and steps with variable PID control gains. This design have been rapidly iterated over the course of a couple months, leading to the final design shown below.

A potentiometer has been incorporated to give additional reliability in case a loss of power results in a loss of known state on the ODrive side. The sequence for the throttle is handled from the remote unit and is incorporated into the auto sequence in addition to the ignition.