[ATM] spider rotation

[Jerry Hillman]

Hi All,
  Can anyone direct me to a site that has built a spider that is not a variation of the common spider that everyone seems to use. Since the placement of the secondary mirror is so critical, I am looking for a design the uses the surface, center of the mirror as the rotation point, not the tip of a adjusting bolt that on my scope places the rotation point about 3 inches away. Makes for a frustrating time trying to adjust the mirror since centering the mirror moves it out of collimation and collimating it moves it out of center. I have about 1/8" offset but same problem applies. I can provide drawings that illustrate my problem.
  Jerry