cracklover wrote:
jt512 wrote:
cracklover wrote:
Aric, the trouble I'm having is that I don't see any correlation between effective cam angle and the point at which the cam slipped.
We wouldn't expect to see a correlation between cam angle and the applied force at which the cam slipped. Accoding to Vaino Kodas's equations, there is no relationship between the applied force at which a cam would slip cam angle. If the cam angle is less than a critical value, the cam will not slip at any applied force; if the cam angle is greater than the critical value, the cam will slip at any applied force.
Let's say the point at which the angle is too great is 30 degrees. If the effective cam angle starts at 29, a little deformation, and presto, you're over the line. So the closer to that magic number, the less force should be required to push you over it. But... that's not exactly what we're seeing.
Now if the relative hardness of the cam lobes is a much bigger factor, then it might erase any correlation based on the starting effective angle. But... I don't see any correlation based on either a combination of the two, or on either individually.
In reply to:
I wonder if it isn't so much a function of the flat spots on the cam increasing the cam angle as it the flat spots making the cam essentially no longer a cam. Would you expect something like this...
[img]http://www.shariconglobal.com/misc/pulltesting/RSaliens/Sample09/sample09_broken_left.JPG[/img]
...to really work like a cam? Or maybe it would. After all hexes hold in parallel cracks.
How exactly that flat spot affects the "friction" is waaaay beyond my paygrade. I'm really just a DBA/developer with a halfway decent grasp of basic physics and a good head for problem-solving.
I agree with Aric, though.
Something is allowing the cams to slip, and it certainly seems to vary from cam to cam. I just don't think we've put our finger on what that key variable, or variables set is, yet. And it's distinctly possible that with such a small dataset, it may not be possible to find it for certain.
GO
