The task was to convert a drill press into a 2.5-degrees-of-freedom CNC milling machine that could move at least 2 inches in the X and Y axis. The mechanism needed to not inhibit the functionality of the drill press.

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All axis operates using belts powered by stepper motors. The X-axis uses two belts driven by two motors to maintain stability and alignment while the central carriage is mounted along the Y-axis and powered by a single belt and motor to reduce weight. Screw holes in the carriage allows for two extruded aluminum parts to become the worktable to which any parts can be attached. The Z-axis uses a belt-driven ~1:3 ratio gear to increase the torque from the stepper motor used. This was to address the difficulties of actuating the lever to lower the drill bit. To further aid the Z-axis, our team shortened the return spring used to automatically draw the drill bit upwards to reduce the required torque on the Z-axis motor.

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My role in the group was to design and 3D print mounts for the motors, mounts for the bearings for the belts, the main carriage along the Y-axis, and the connector for the Z-axis belt. I used a digital caliper to measure and validate the 3D print measurements. I also utilized and maintained FlashForge 3D printers to produce the required parts for this project. 

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As a result, the CNC machine was able to mill a rough maximum volume of 7.5in x 8in x 0.5in. As demonstrated in the video, it was able to mill a flat squared surface from the uneven block of wood. The mill was controllable using Repetier-Host through G-code with a milling software.

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