This is a very useful servo accessory that I have made to remotely actuate panel-mounted fuel valves. Designed to fit most 1/4 in compression needle valves, this adapter interfaces these valves with a servo motor so I don't have to be close to my rocket engine test stand if things go horribly wrong. It is supposed to use a 25kg-cm servo motor with 270 degrees of rotation in order to have enough torque to fully open and close the valve. This adapter can be used with remote control or Arduino to remotely control the flow rate of any type of fluid. It can also be used with ball valves if the "valve_turner" part is slightly modified. From automation to remote control vehicles, being able to remotely control fluid flow rates can be extremely useful.

Printing:
the two parts of this assembly will be subject to very high torques when the valve is being turned so use a strong and rigid material with 100% infill. use support on both parts and a brim if adhesion is an issue.

Assembly:
First, use 4x #6-1/2in thread-forming screws to attach the high-torque servo to the top of the servo holder. Then, use an M3 x 10mm machine screw (or whatever fits your servo) to compress the valve turner on to the servo until it sits flush with the servo bearing. It may require a considerable amount of force to tighten on the valve turner as any misalignment in the printer may have the interlocking gear pattern be too tight. A tight fit is helpful though, as it will help transfer the torque more effectively. Once assembled, use 6 screws to mount it to any panel with a valve and make sure to align the valve axis with the servo axis. use a servo tester to make sure it rotates freely and if so, your servo valve is complete.

Notes:
do not use on any valve that cannot be easily turned by hand as significant torque could shear the parts along their layer lines. THIS VALVE DOES NOT AUTOMATICALLY CLOSE IF POWER IS LOST! When using for flammable gasses/liquids, always use a solenoid valve in conjunction with this valve so that flow can be stopped if there are any power or signal problems. Make sure you always have a failsafe option when dealing with any fuels or chemicals.