Downhole jack assembly sensor

1. A drill string comprising:

a drill bit with a body intermediate a shank and a working face, the working face comprising at least one cutting element;

a jack assembly disposed within the drill bit body and comprising a jack element disposed on a distal end of the assembly;

the jack element substantially protruding from the working face and being adapted to move with respect to the bit body; and

at least one position feedback sensor disposed proximate the jack assembly and adapted to detect a position and/or orientation of the jack element with respect to the drill bit;

wherein the jack assembly comprises a driving shaft disposed intermediate a driving mechanism and the jack element;

wherein the jack assembly comprises a geartrain disposed intermediate the driving mechanism and the driving shaft; and

wherein the at least one position feedback sensor is disposed within the geartrain.

2. The drill string of claim 1 , wherein the at least one position feedback sensor is adapted to calculate a velocity or oscillation frequency of the jack element.

3. The drill string of claim 1 , wherein the jack element is adapted to rotate about a central axis.

4. The drill string of claim 1 , wherein the jack element is adapted to translate along a central axis.

5. The drill string of claim 1 , wherein movement of the jack element is powered by a downhole motor.

6. The drill string of claim 1 , wherein the at least one position feedback sensor is powered by a downhole power source.

7. The drill string of claim 1 , wherein the at least one position feedback sensor is in electrical communication with a downhole network.

8. The drill string of claim 1 , wherein the at least one position feedback sensor is part of a bottom hole assembly.

9. The drill string of claim 1 , wherein the at least one position feedback sensor comprises a hall effect sensor, an optical encoder, a magnet, a mechanical switch, a rotary switch, a resolver, an accelerometer, or combinations thereof.

10. The drill string of claim 1 , wherein the at least one position feedback sensor senses the position and/or orientation of the jack element by recognizing a characteristic of a signal element disposed proximate the sensor.

11. The drill string of claim 10 , wherein the characteristic comprises a change in density, geometry, length, chemical composition, magnetism, conductivity, optical reactivity, surface coating composition, or combinations thereof.

12. The drill string of claim 10 , wherein the signal element comprises a generally disc-shaped geometry, is disposed in the jack assembly, and is mechanically coupled to the jack element.

13. The drill string of claim 1 , wherein the drill string comprises a plurality of position feedback sensors.

14. The drill string of claim 1 , wherein the jack element comprises a distal deflecting surface having an angle relative to a central axis of 15 to 75 degrees.

15. The drill string of claim 1 , wherein the drill string further comprises at least one electrical component selected from the group consisting of direction and inclination packages, generators, motors, computational boards, position feedback sensors, accelerometers, or combinations thereof.

16. The drill string of claim 15 , wherein the at least one electrical component is rotationally fixed to the drill string

17. The drill string of claim 15 , wherein the at least one electrical component is rotationally coupled with respect to the jack element.