The task was to design a mechanical mechanism to lift a pen by at least 1". We were able to use a 28BYJ-48 stepper motor to actuate the motion and FDM 3D printers to construct the mechanism. 

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The design is a parallel 4-bar linkage (2 pairs of equal lengthed bars) that lift the pen when rotational power is applied to the upper arm. The motor was controlled using an Arduino Nano using Arduino IDE with a motor driver.

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The mechanism has a molded contour to the specifications of a red office pen, allowing for a snap fit without glue. This holder firmly grips the pen which didn't move when pushing vertically on the pen.

 

As a result, the mechanism was able to move the pen up to 4 inches vertically. The device did offer a small amount of resistance (enough to draw a line), however, there was just enough torque from the motor to return the pen to the upper position. Upon a redesign, I would shorten the horizontal arms to reduce the torque required to lift the pen.