Alex,
Use the Slot Machine blade for plastic hd hinges
http://www3.towerhobbies.com/cgi-bin...?&I=LXPT33&P=7 . It creates a wider slot than the one for ca hinges or the standard nylon hinge blade. I use a exacto rip blade to open up the slot just a bit if needed. I also built a table and stand for my machine with a guide fence.