1. 2.72 Group 5 Design Review 1 2/23/08 Eric Correll, Josh Gafford, Andrew Marecki, Stephen Powelson, Johannes Schneider, Sam Weiss

2. 2.72 Group 5 - Spring 20092 Objective Project timeline and updates Introduce shaft design Calculations, diagrams, and results Further discussion

3. GANTT Chart …wait one second…

4. Individual Updates Steve – Solid Model Sam – MathCAD Eric – Machining Andy – Documentation Josh – FEA Johannes – Measurement

5. Measurement

6. Shaft Design

7. Calculations Typical cutting force: 500N Part yield at ~1000N (3/8” Al, cut 1.25” from chuck) Tensioning force from pulley, 2 to 3kN max

8. Safety Factor Minimum safety factor given stress concentrations is n=1.3

9. Deflections and Angles

10. Deflections and Angles (cont.) FEA confirms MathCAD analysis. Compare FEA of solid model (above) with MathCAD calculated deflection (in red, right).

11. Questions Is the bearing order only for the spindle bearings? Chuck fitting and size? Motor specs (torque-speed curve)? Motor mounting fixture? Pulley tensioning?