4. Conclusion

The contact points for the two end effectors occur when θ₂ is 205.7 degrees. The total Mechanical advantage of the system at that point is 0.025. This means that the force applied to the crank handle is decreased by a total factor of 40.

If the input was a torque instead of a crank, this would be equivalent to:

Given the input radius value of 1.25 in, the output force is equivalent to the input torque multiplied by a factor of 0.02. This is a decrease by a factor of 50. 

The takeaway is that the current system would need a very large motor to be able to hold objects of small mass. Inherently this is not desirable for most applications as motors become exponentially more expensive with the increase in motor power. This can be changed by increasing the gear reduction ratio with a gear train of sorts.

One thing the decreasing factor does help is in the world of collaborative robotics. The system is fairly back-driveable, so a reaction force on the end effector will cause a reaction torque on the input linkage. This reaction torque is actually increased by a factor of 50. If the input linkage is capable of measuring reaction torque, such as a series elastic actuator, the torque readings will be amplified, and thus easier to detect.