DX6i center throttle

If you are using a plane/copter with your DX6i, you normally
have zero throttle at stick down.

If you sometimes want to use a RC car or a 3D copter with reverse,
you might need to have zero throttle at middle stick.

You can permanently change that with some 3D printed parts and a
spring, but you will need to open the radio each time you want
to change the vehicle.

With this add on, you can use a rubber band to temporarily have
throttle zero at middle stick.

It should work with t