[ATM] Re: Second Thoughts on Mirror Support

[sho at surfnetUSA.com (Steve Houlihan)]

Thanks Michael for the help with the math, but I need more of an explanation
than this.
>
> I agree that you want the moment arm to be as small as possible, but I
think
> your numbers are off a little bit. Yes, there are 7 inch pounds of torque,
> but the moment arm for each pad is about 7/8 (a factor of
> 1.75/sqrt(1.75^2+1)) of 1/2 that or about 3 pounds. Furthermore, the force
> vector is at an angle, and the push component of that is about 1/2 (a
factor
> of 1/sqrt(1.75^2+1)) or about 1.5 pounds. As usual, corrections to my math
> are welcome.

This is hard to figure without a picture.  I guess you are looking at the
actual force vector through the pad and I was only looking at the force
perpendicular to the back of the mirror.  Is that right?

Steve Houlihan
Santa Cruz, California

sho@SurfnetUSA.com
http://sho.mystarband.net/
http://www.surfnetusa.com/sho