Exercise machine with pancake motor

1. An exercise machine comprising:

a pancake motor, wherein the pancake motor is in an out-runner configuration;

a torque controller coupled to the pancake motor;

a spool coupled to the pancake motor, and a cable wound about the spool;

an arm to position the cable, wherein the arm comprises: 1) an arm slider to translate the arm and guide the cable along a rail associated with the arm, 2) a vertical pivot locking mechanism to position and keep the arm in a fixed vertical pivoted position, and 3) a horizontal pivot mechanism for the rail;

an actuator coupled to the cable at an end of the arm;

a high resolution encoder coupled to the pancake motor wherein the high resolution encoder determines motor position of the pancake motor; and

a second encoder with resolution lower than a high resolution encoder, wherein the second encoder determines position of the actuator.

2. The exercise machine of claim 1 , further comprising a voltage stabilizer coupled to the pancake motor to dissipate power, wherein the voltage stabilizer comprises a control signal to modulate power dissipated through a resistor.

3. The exercise machine of claim 1 , wherein the exercise machine is a strength training machine.

4. The exercise machine of claim 1 , further comprising a differential coupled to the pancake motor.

5. The exercise machine of claim 4 , further comprising a first spool and a second spool, each spool coupled to the differential.

6. The exercise machine of claim 5 , further comprising: a first arm; a second arm; a first cable; and a second cable, wherein: the first cable is wound about the first spool; the second cable is wound about the second spool; the first arm positions the first cable; and the second arm positions the second cable.

7. The exercise machine of claim 6 , wherein the pancake motor, first spool, and second spool are mounted near the top of the exercise machine.

8. The exercise machine of claim 6 , wherein the cables are routed over the top of the exercise machine.

9. The exercise machine of claim 1 , further comprising a low profile gear box coupled to the pancake motor.

10. The exercise machine of claim 1 , further comprising a low profile differential coupled to the pancake motor.

11. The exercise machine of claim 1 , wherein the exercise machine is low profile.

12. The exercise machine of claim 1 , further comprising a second pancake motor.

13. The exercise machine of claim 12 , further comprising a first spool and a second spool, wherein the first spool is coupled to the pancake motor, and wherein the second spool is coupled to the second pancake motor.

14. The exercise machine of claim 13 , further comprising: a first arm; a second arm; a first cable; and a second cable, wherein: the first cable is wound about the first spool; the second cable is wound about the second spool; the first arm positions the first cable; and the second arm positions the second cable.

15. The exercise machine of claim 1 , further comprising a wall bracket, wherein the exercise machine at least in part hangs on the wall bracket.

16. The exercise machine of claim 1 , wherein the pancake motor has teeth compatible with a belt integrated into a body of the pancake motor along an outer circumference.

17. The exercise machine of claim 1 , wherein the pancake motor uses cable tension and gravity to move a slider up and down to desired positions for a first arm.