-- MicheleLanzetta? - 30 Sep 2004 - measurements and analyses of actual spine/claw tip size used in the Rise feet (NewFootDesignsJune04, FootDesign, FootAndLegTrajectoryStepTest etc.)

Measurements

Measurements assume a calibration factor of 1.67 micron/pixel.
All images taken (51x44MB) can be found in "\\Chewie\users\lanzetta\Claw Tips"

Spine/Claw type/image filename Diameter
[micron]
Tip diameter
[micron]
Sample images Notes
CommercNeedleLarge.bmp >3000 400 CommercNeedleLarge.bmp
Pin0.1_1.bmp
Pin0.1_2.bmp
Pin0.1_3.bmp
Pin0.1_4.bmp
Pin0.1_5.bmp
Pin0.1_6.bmp
Pin0.1_7.bmp
100 25
20
30
30
25
50
20
Pin0.1_1.bmpPin0.1_2.bmpPin0.1_3.bmp
Pin0.1_4.bmpPin0.1_5.bmp
Pin0.1_6.bmpPin0.1_7.bmp
Pin0.2_1.bmp
Pin0.2_2.bmp
Pin0.2_3.bmp
Pin0.2_4.bmp
Pin0.2_5.bmp
Pin0.2_6.bmp
Pin0.2_7.bmp
200 20
20
50 broken
50 broken
25
15
20
Pin0.2_1.bmpPin0.2_2.bmpPin0.2_3.bmp
Pin0.2_4.bmpPin0.2_5.bmp
Pin0.2_6.bmpPin0.2_7.bmp
StdPin1.bmp
StdPin2.bmp
StdPin3.bmp
StdPin4.bmp
StdPin5.bmp
StdPin6.bmp
StdPin7.bmp
StdPin8.bmp
>350 75
200
120
70-170
120
130
160
60
StdPin1.bmpStdPin2.bmpStdPin3.bmp
StdPin4.bmpStdPin5.bmpStdPin6.bmp
StdPin7.bmpStdPin8.bmp
footallthree.bmp

Foot used in wall tests with carpet

A clear explanation of difficult disengagement...
200 distorted
70
70
footallthree.bmpfootleftclawfromleft.bmp from left
Dana.bmp

Manually sharpened by Dana
200 20 Dana.bmp  
Surgical.bmp 150 30 Surgical.bmp  

Conclusions

  • This analysis shows that the variability among both manually made and commercial pins can be very high, so, of course, the performance of each foot should be carefully evaluated also considering the actual tip size of spines/claws used.

  • Maybe obvious: smaller commercial pins not necessarily have smaller tip diameter. So commercial spine/claw material should be selected considering the actual tip size. E.g. the 100 and the 200 micron pins have the same minimum tip size.

  • The lower bound for most spines/claws is found to be 20 micron (as assumed in the profilometer analysis SurfaceProfileAcquisition)

  • Manual sharpening can lead to the best commercial size available (20 micron), so larger spine/claw materials can be used if required for structural reasons (less stronger spines/claws engaged)

 
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