Mechanical Design

Most of the preliminary mechanical design was done using Unigraphics. Using Unigraphics gave us better visibility for forecasting any mechanical needs that the plotter would require. The design of the x-y plotter consisted of four major subassemblies: a frame, x-translation assembly, y-translation assembly, and solenoid assembly.

Frame

The frame consisted of a .25” thick aluminum which gave envelope dimensions of roughly 14x18x3 inches. Its main functions were to support the other subassemblies as well as to provide means of supporting the writing surface. Included in this frame assembly are a top panel and a bottom panel which provided mounting surfaces for the switches/white board and motor respectively.

X-Translation Assembly

This assembly is what provided the x directional motion of the plotter. A motor drove a gear on one of the shafts which in turn drove the pulleys and belt. The belts provided the linear motion and had to be tensioned significantly so as not to sag under the weight of the y-translational assembly which rests upon these belts.

Y-Translation Assembly

This assembly held a motor mounted to a “sled” which was allowed to move across a bracket. Motion was translated from the motor through the rack which creating a linear motion in the y-direction. A small strip of aluminum played a crucial role and acted as a rail, not allowing the sled to become skewed with respect to the rack.

Solenoid Assembly

This assembly consisted of a bracket which held the solenoid and allowed it to attach to the sled used in the y-translational assembly. The bracket also confined the solenoid actuation and maintained the orientation of the pen with a tube which was attached. This tube limited pen movement to the z-direction only.