Document Type

Undergraduate Project

Date of Degree Completion

Spring 2018

Degree Name

Bachelor of Science


Engineering Technology

Committee Chair

Dr. Craig Johnson

Second Committee Member

Professor Roger Beardsley

Third Committee Member

Professor Charles Pringle


Apple orchards are a critical component of agriculture in the United States, and keeping the apple trees in the best shape for optimum growth and production is hard work. Neil Hauff, an agriculture industry expert, challenged students at CWU to engineer a power assisted tree pruner. Across the country, apple orchards need pruned every season. The pruning of the trees is strenuous manual labor that requires many man hours. The proposed solution is to create a power assisted tree pruner that would minimize the amount of work needed to trim each tree branch. This project has been separated into three main components; power drive system, housing and ergonomics, and the cutting blades. The main focus of this report was the optimization of the pruners cutting blades and their ability to cut branches quickly and repeatedly. The entire device was created by utilizing an electric impact driver and converting the rotational motion into linear motion that would actuate the cutting blades. The cutting blades were designed to open large enough to cut a 1.50” diameter branch, and use a linear pulling force of 1000 lbs, supplied by the impact driver. Testing showed that the cutting blade assembly was capable of withstanding the 1000 lb force applied by the drive system. This report describes the motivation, engineering analysis, and results of testing the cutting blades within the device.