locating and mouting a spoilboard

I have just has my BT48 alpha for just over a week and I am trying to determine where to locate and how to mount my spoil board.

My idea is to move the spindle to the X extent, move Y about 4", cut a 1/4" hole, move along Y 44", cut another 1/4", move to Y extent, move X 20", cut another 1/4" hole.

Insert dowels into the three holes and located my 24" X 48" X 1" MDF spoil board against the dowels and mount the spoil board .... how?

My first idea is to use 1/4" X 20 flat head brass screws, in 6 locations, through the MDF and into threaded holes in the Buddy table.

I would have included some photos/images but I am new to this site and do not know all of the in/outs of how do do things as yet!

CAD image:
DID NOT WORK!

PDF drawings:
https://docs.google.com/open?id=0B80...2F5b3ZHb3VBVm8

I tried to an image and CAD prints for the first time ... did not work!

Can anyone tell me why what I am doing wrong with my picture post?