Group 2

1
Group 2 Progress Report

• 2/23/09

2
Purpose (Justin)

• Talk about progress the past week
• Fabrication of shaft
• Shaft exercise
• Lessons learned
• Getting ahead of schedule

3
Gantt Chart (Justin)

• (Switch to Excel)

4
Stiffness Calculation (Corey)
5
Spindle Shaft Dimensions (Corey)
6
Stiffness Calculation (Corey)
Length (in) Length (m) Diameter (in) Diameter (m) Area Momentof Inertia K's
1 0.0254 0.5 0.0127 1.27698E-09 4.68E07
4 0.1016 1.05 0.02667 2.48349E-08 1.42E07
0.87 0.022098 0.89 0.022606 1.28193E-08 7.13E08
0.63 0.016002 0.591 0.0150114 2.49261E-09 3.65E08
           
YoungsModulus (Pa)   Keq (N/m)   Keq(N/mE-6)  
2.00E11   10426059.6   10.4260596  
Keq10.426 N/µm
7
Pre-process Plan (Yi Fei)
C
B
D
A

• Face-off right most face
• Drill live center
• Rough cut section A, B, C, and then D
• Finish cut section A, B, C, and then D
• Cut part to length, take part out

8
Process Plan (Yi Fei)

• Face-off right most face
• Drill live center
• Turn down whole length to 1.07 diameter
• Rough cut and finish cut section C, B, and then A
• Take part out, cut to length, turn part around
• Rough cut and finish cut section D

C
B
D
A
9
Manufacturing (Mark)

• Details

10
Manufacturing (Mark)
11
Manufacturing (Mark)
12
Test Cut Results (Corey)
Initial Diamter (mm) 28.575
Target Diameter (mm) 27.305

• The measured diameters were greater than the
  target diameter
• The largest diameters were measured from the
  cantilevered cuts
• .003 error in touching off tool
• Free end cuts were performed last

Cantilevered Cuts Diameter (mm) Mean (mm) Mean (mm)
1 27.73 Mean (mm) Mean (mm)
2 27.88 27.91 27.91
3 27.71 27.91 27.91
4 27.74    
5 27.76    
6 28.03 Std Dev Std Dev
7 28.06 Std Dev Std Dev
8 28.06 0.16 0.16
9 28.14 0.16 0.16
10 27.99    
       
Free End Cuts Diameter (mm) Mean (mm) Mean (mm)
1 27.73 Mean (mm) Mean (mm)
2 27.56 27.685 27.685
3 27.74 27.685 27.685
4 27.71 Std Dev Std Dev
    Std Dev Std Dev
    0.08 0.08
Exposed Length (mm) 138.11 0.08 0.08
13
Fabricated Shaft (Corey)
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(Non) Systematic Errors (John)
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Nonsystematic Errors - Thermal
From Manufacturing Engineering and Technology -
Kilpakjian
CTE12.2 µm/m-C ?L1 µm
16
Non-Systematic Errors Vibration

• Rotating machinery may excite natural frequencies
  of lathe, tool, or shaft.
• ? Be sure work-piece is centered
• ? Hold shaft with both chuck and live-center
• ? Hold shaft as close to cutting zone as possible

17
Systematic Errors Tool slip or work-piece slip

• Cutting forces may cause the tool or work-piece
  to shift because both are held with friction
  forces only.
• Cause a shift in mean results
• ?Use moderate feed-rates and depths of cut
  (accuracy more important than time for this
  operation)

Cutting forces on order of 250N-1000N
http//www.sabanciuniv.edu/mdbf/mechatronics/eng/A
rastirmalar/Projeler/images/clip_image008.jpg
18
Systematic Errors Tool Wear

• Any tool wear will result in oversized dimensions
• Not enough cutting done to be a large factor of
  error
• ?Check tool-zeroing often

Taylor-Tool Life Expectancy Eqation V_cTn C
19
Concerns

• Will the current shaft work?
• Making sure the second shaft gets manufactured
  properly