This is a system to level the bed of a CR-10 3D printer using four dials at the front. They turn four sets of gears which mesh with gears that spin the four bed leveling screws beneath the bed. This allows full adjustment of the bed during operation, without placing your hand under the bed (very difficult while moving). Additionally, one spin from a front dial will increase the bed height by .25 millimeters.
It works by using a square rail to transmit rotations from a front dial to a gear that slides along the shaft and is also held in place next to the leveling gear. The leveling gear fits around the hand screw that adjusts the height of the bed.
The only thing not printed is a 3/16" 3' metal square bar to act as a non-circular rail (see links below):
Helix Angle: 60
Helix Angle: 30
I'm sure there are plenty of adjustments that need to be made for the HickTop (mine) vs the Creality versions. And this could be modified to fit entirely different platforms with similar a bed leveling adjustment mechanism. I've assembled the parts in a combined Fusion 360 (https://a360.co/2kIADDH)
Edit: I noticed that if you mirror two of the slide gears, and mirror the associated thumb screw gears (so that they are left handed threads), the new setup will allow all four of the front dials to spin in the same direction to move the bed up/down (one left handed set for the right pair of rails, and one left handed set for the left pair of rails). That's also an optional part to attach a camera to.