I had the fuselage in a jig, so I used a square to get the mount perpendicular to the table and aligned with the 2 degrees of offset on the plans.

What thickness of plywood do most of you use.  I've seen what looks to be about 1/4" from the photos posted.

Heman,
      I construct my motor mount blanks by by making a balsa,1/32 ply and carbon fiber composite sandwich.First I cut a slice of endgrain balsa 2 1/2" X 2 1/2" that is 1/4" thick.2-2 1/2" X 2 1/2" squares of 1/32" ply.4- of the same size squares of .05 carbon mat.Last I have some unwoven carbon strands.The glue-up is pretty simple.Apply slow cure epoxy to 1 side of a piece of 1/32" ply.Lay one piece of carbon on it then take some carbon strand and make an X pattern with it diagonaly.Apply 1 more square of carbon.Make sure to get the carbon wetted with glue.Apply glue to both sides of the 1/4" end grain balsa and put it on the carbon/ply.Do the second piece of 1/32"ply just as the first and place it carbon side down down on the balsa 90 degrees from the grain of the first piece.You should now have a ply,carbon,balsa,carbon,ply sandwich.Make sure to use wax paper and clamping cawls(blocks) when you glue this up.Make sure to have everything ready to glue BEFORE you mix the glue so you can get it layed up as fast as you can and clamped before the glue starts to kick.You end up with a light VERY strong motor mount blank.The endgrain balsa and the crossed carbon strand make it crush resistant.Cut the blank to suit or make it bigger.You can use a thinner balsa core but in composites the thicker the core the better.The farther apart the carbon/ply skins the stronger it will be.When you go thinner it will start to lose its strength.