Shigley Loader
An exercise in mechanical design with component constraints.
The Shigley Loader is a gear-driven winch that is used to haul heavy loads (Shigley’s Mechanical Engineering Design textbooks) up an incline plane at varying angles.
The design needed to incorporate a Mabuchi RE280 DC-Motor and a provided set of spur gears 2x (10T, 20T, 40T, 50T).
*Please refer to the PDFs in the DOWNLOADS portion on this page for a thorough overview.
YEAR: 2015
ROLE: Engineer, Machinist
STATE: Finished Prototype
Collaborators:
Strategy
The goal of the Shigley Loader’s design was to haul a specified number of Shigley textbooks (1-5) up a ramp with angle ranges from 20° to 60°.
Photo: A 9th Edition of Shigley’s Mechanical Engineering Design; the “standardized” weight used to test the design. This textbook has the dimensions of of 260mm x 210mm x 40mm and weighs roughly 4 lbs. 12.5 oz.
Cold-drawn steel rods of diameters 3/16” and 1/4” were used. The choice of material was based on the material’s high yield strength and economy. The 3/16” dia. rods were used on the first two gear shafts (in respect to the motor) where the bending forces are the lowest, and the 1/4” dia. rods were used on the last two gear shafts where torques, forces, and bending moments were the highest.
Photo: An FEA on the upper shaft that holds the spool. The FEA was done solely on the shaft that would hold the spool since it would experience the largest loads.
Photo: The von Mises stress of this rod under the heaviest load condition of five Shigley’s, which produced a force of 108.05 N in addition to the weight of the cart. The largest stress would occur at the location of the spool.
FINAL DESIGNS
This project provided the contrast between theoretical design performance and actual design performance (granted that we got close to theoretical during testing); a great learning experience in mechanical design, manufacturing, and testing.
For a full report, please see the DOWNLOADS section below:
