Date of Degree Completion
Mechanical Engineering Technology
Dr. Craig Johnson
Second Committee Member
Professor Roger Beardsley
Third Committee Member
Professor Charles Pringle
The H.F. Hauff Company invests a large amount of money in developing a quality pruner used in everyday agriculture. Modern electric pruners tend to be expensive while manual tree pruning is very physically demanding. A battery assisted pruner that is light-weight, ergonomic, inexpensive to build and powerful enough to cut branches that a nominal apple tree would possess is the direct affiliation that H.F. Hauff devotes its funding too. A team of engineering students from Central Washington University developed a product with consideration to each of these circumstances. Since hand drills have proven to be user friendly and of abundance in the agricultural industries due to the nature of machinery, the pruner is an attachment to a hand drill. An innovative self-reversing ball screw converts the rotational energy to linear energy driving the cutting blade utilizing a power efficiency of 90% and allows the drive train to reciprocate providing an unassisted return of the blade to the open position. Calculations prove that the average torque of a common drill nears 450 inch-pounds of torque fostering a linear force of nearly 1000 pounds. This Linear force satisfies the testing needed to cut a 1.5 inch branch which commonly occurs on the average apple tree. The pruner assembly costs $300 for material and manufactures using tool commonly found in industry keeping the price under $500 compared to competitive electric pruners upwards of $1000.
Graff, Grady, "H.F. Hauff Electric Pruner Drive Train" (2018). All Undergraduate Projects. 76.