ATM Flat mounting plate for solid tube?

[Xakxak@aol.com]

Does anyone have experience installing a flat mounting plate on a solid tube.  I figured 
if I could do that it would be easier to square the focaser if there was a mounting plate 
that was square to attach it to.  Seems it would be alot sturdier as well.  
     The sonotube I am using (14") is alot thicker than the 8-12" tubes (from 14" and up 
the tubbing is thicker) so I don't think it would effect the strenth of the tube by 
cutting a chunk out of it for this project (if that is neccessary).  Is this a good idea 
or is it just as difficult to to square a mounting plate?  Would it make the focaser 
profile too low or make the focaser tube interfere with the light path?  Should I even 
bother since I have a fairly strong tube?  Any tips?

FYI:  O.D. = 14 1/4"
      I.D. = 13 15/16"
      Wall thickness = 3/16"
      Primary mirror = 12.5"
TIA!
-Pete