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Unread 10-22-2010, 03:36 AM
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VEX Robotics Engineer
AKA: Arthur Dutra IV; NERD #18
FRC #0148 (Robowranglers)
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Re: pic: Stress plots related to broken output shaft

Quote:
Originally Posted by M. Mellott View Post
One option that comes to mind might be to use a tool that has radii in the bottom corners (or completely rounded on the bottom and cut your groove a few thousandths deeper) rather that sharp points. Sharp edges are stress concentrators, so the blends might remove some of the stress points.

Now, one might say a completely rounded groove bottom might also take away too much of the vertical side walls of the groove and defeat the primary purpose--holding a snap ring and supporting an axial load...but some snap rings have rounded cross-sections, so...
Personally, I'm a fan of just using Delrin spacers in the high torsion areas of shafts to transmit any axial loads to whatever is being used for shaft retention (stepped shafts, tapped ends with washer, snap rings, etc) at the non-torsionally-loaded ends of the shaft.
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Art Dutra IV
Robotics Engineer, VEX Robotics, Inc., a subsidiary of Innovation First International (IFI)
Robowranglers Team 148 | GUS Robotics Team 228 (Alumni) | Rho Beta Epsilon (Alumni) | @arthurdutra

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