1. Mast Design Proposal Presented by Doug Eddy and Dr. Sundar Krishnamurty at UMass Amherst for Hoppe Tool on 8/13/10

2. What do we recommend? 2-Sided multi-scissors lift driven by horizontal lead screws with carbon fiber tubing scissors

3. Why??? An economical version of a high end strong design – The design must be strong to start the lifting. Minimizing the number of sides minimizes the cost, weight, number of components, etc. Carbon fiber tubing is likely the lightest, strongest, and stiffest possible component. The most stable, lightweight, high performance, and trouble-free drive design

4. What are the dimensions in inches? The motor and perhaps cable basket (15” height) can be mounted below in the footprint.

5. What about the stability?? Even at the max 200 pound payload on a 20% grade accelerating to 10mph in about 1 second, the sway deflection will be only about 1 inch.

6. What about the 3-sided design?? Carbon fiber tubing cost would go from $6500 to $9100. – There are other costs that would also increase by nearly 50% for pin shafts, bushings, screws, gears, etc. Accurate alignment is crucial to satisfactory performance and easier with the 2-sided design for both the scissors and the drive mechanisms. Gear space and gear size are minimized when 2-sided. 2-sided is the most effective design to use the Horizontal screw: – Economizes vertical space – Enables a longer nut and pitch for faster speed – Much more strong, stable, and reliable drive system

7. Any ideas for safety and protection? An optional removable bellows can be used to cover and protect the mechanism components.

8. Please Summarize Reliability is improved by using fewer components. Stability is 10x better than the military spec. Carbon fiber tubing and a compact drive reduce weight while increasing strength and performance. Longer nut on the horizontal screw can increase speed Fewer components also minimizes cost