Design of a tree moving and planting device

Abstract

Planting trees that weigh over 200 pounds normally requires three or more able persons. Therefore, a device that allows a single person to easily and efficiently plant such trees possible by one person is highly desirable. During a Product Design class in the Mechanical Engineering Department at the Massachusetts Institute of Technology, a group of 14 students developed a series of four concept models which culminated in a Final Prototype of such a product that can successfully lift, move and plant trees of over 200 pounds. This paper is aimed at documenting this series of designs and analyzing, testing and further developing the Final Prototype built in the course in order to make it marketable. Based on customer feedback, testing results, and user interaction, revisions to the next prototype of this device are proposed. Testing with trees of 170 and 370 lbs determined that the current outrigger stabilizing mechanism needs modification. The current outriggers, which are stored inside the frame, sustained maximum loads of 29 lbs for the 170 lbs tree, and 46 lbs for the 370 lbs tree. A sketch model built to simulate the outrigger mechanism suggests that the outriggers should be attached outside the base frame of the device rather than stored inside.

(cont.) The revised device is also to include two stacked pipe clamps for securing the vertical member members of the outriggers. The upper and lower frames are to be reduced in width from 42 to 36 inches, making the device more compact while still accommodating tree root balls of up to 3 feet in diameter. Nylon insulation of the current winch wire is necessary to prevent damage to tree trunks while operating the device. These design revisions will improve the performance of the device Final Prototype and are believed to make the revised device commercially viable on the product market.