Fox Freehead

A Final 2021 Update on the Fox Freehead

One final check in before we take a few days off for the holidays. The Fox Freehead is now about 90% repaired. I have been working on the frozen tilt axis for the last week; it is another remarkable piece of engineering. The tilt axis is made up of a two-part casting that houses the hydraulic grease which works as the damper material, and a wiper arm with metering valve that works as the axle that the tilt axis moves on. What’s remarkable is that the wiper arm remains stationary as the two part casting moves through its rotational arc. The stationary wiper arm acts to displace the hydraulic grease through the metering valve as the camera operator tilts the head up and down.

Both the pan and tilt hydraulic dampers are protected by very clever pressure relief valves, which as it turns out, are causing me troubles getting the tiny bit of remaining air out of the system. I have had to take this apart several times, once to remove the original contaminated grease, once to restore the original cotton string gasket seals, once to replace the failed gasket that seals the two halves of the casting, and finally to replace that replacement gasket that turned out to be .005” too thick. Other than a little bit of air that needs to be worked out, it is now back together and working properly. And with that, I bid you all a happy holidays and a joyous new year. See you in 2022!