Years ago, I started to use a laser to adjust prop blades so they were all the same. It really works good, you can actually see the light move when you tighten the bolts. Way more accurate then a warp drive protractor I believe. Cost was about $8 for the laser pointer from ebay, and the rest was just stuff I had around the place. Here is a video of the one I made for the NR prop I got last year. JImChuk
laser prop setting tool - YouTube