Document Type

Undergraduate Project

Date of Degree Completion

Spring 2023

Degree Name

Bachelor of Science


Engineering Technology

Committee Chair

Charles Pringle, PE

Second Committee Member

Dr. John Choi

Third Committee Member

Mr. Chris Berkshire


The purpose of this project is to build and improve on the carbon-fiber recycler at Central Washington University. The carbon-fiber recycler consists of four components such as a crusher, shredder, conveyor, and oven. This report will focus on the shredding and gearing elements. The chain drive on the shredder and the gearing module were replaced with a synchronous belt drive.

The pitch diameters for the sprockets on the shredder and the center distance of the shafts was evaluated to find the belt length. The velocity ratio and the angular velocity was used to find the minimum torque on the shaft. Lastly, the torque and pitch diameter were used to calculate the force on the belt. The center-to-center distance for the shafts between shredder and motor was reduced from 30.44 inches to 25.5 inches by manufacturing 4 in. x 7 in. x 2 in. spacers. The motor for the gearing component was moved downward an inch. The linear velocity ratio for the sprockets on the gearing device was changed from a 2.54:1 ratio to a 3:1 ratio to minimize the number of RPMs. A sound meter was used to measure the sound of the machine and a tachometer was used to measure the rotational speed. The intent to change the chain drive to a synchronous belt drive is to reduce the sound of the machine.

The sound of the machine was reduced by 50% when operating. The gearing portion achieved a minimum of 1000 RPMs when in operation.