Department - Author 1

Mechanical Engineering Department

Degree Name - Author 1

BS in Mechanical Engineering



Primary Advisor

John Ridgely


Executive Summary:

The Inyo National Forest is arguably one of the most beautiful locations in California, containing natural masterpieces such as Mount Whitney and the Ancient Bristlecone Pine Forest. Despite its magnificence, the Inyo National Forest can be a treacherous region. The Friends of the Inyo take pride in being able to facilitate the viewing experience for all outdoorsmen by maintaining the mountain trails, which includes providing adequate trail signage.

Unfortunately, there is a fundamental issue with the recent state of trail signage in the Inyo National Forest: the rate at which signs are being vandalized or naturally destroyed is greater than the rate at which signs can be produced. More specifically, the problem is that the current sign production process is completely manual; the process of routing the necessary letters and symbols consumes the majority of the production time, since it takes approximately two days to complete. Without adequate signage on the mountain trails, hikers and explorers are at a heightened risk for injury.

We, the Cal Poly Forest Friends, have been commissioned by the Friends of the Inyo to resolve the issue of manufacturing trail signs. We plan on designing, building, and testing a prototype CNC machine for Paul McFarland, an employee of the Friends of the Inyo whom is responsible for replacing signs. This CNC machine can automatically produce a trail sign from a wooden blank so as to expedite the sign replacement process. By comparing different industry methods of etching letters into a wood substrate, researching all applicable signage guidelines for compliance, and optimizing the prototype design for the intended use cases, we have developed a low cost, high capacity CNC router that can be installed directly in Paul McFarland’s workshop.

There has been much work done in the field of CNC machinery, so we believe it is feasible to design a functioning prototype that has been optimized for this purpose. The positional accuracy range of the machine will be broadened from the industry standard of ±0.0005 in to our requirement of ±0.063 inches. This optimized accuracy will allow for emphasis on increased workpiece capacity at a lower total cost. Additionally, by building the prototype CNC router as part of the Cal Poly Multidisciplinary Senior Project class, we will be able to adhere to the revised $3,500 budget. With a successful prototype in hand by June 2015, the sign production rate for the Friends of the Inyo will potentially increase tenfold, and provide the Friends of the Inyo with the ability to replace illegible trail signs within the Inyo National Forest.