Ya know, the folks who really have good experience building props do not let many of their secrets out. As a rank amateur I'm happy to talk about it.
For example, the prop carver I made is perhaps a little taller than it needs to be so as the stylus follows the prop template, the router cuts in an arc. Not a huge problem--the stylus can be adjusted to compensate but it's not the straight vertical cut one might imagine. The cut is going to be an arc in any case but keeping the pivot point as close to the prop as possible would minimize it.
I got impatient and used an ordinary straight router bit but would've gotten nicer cuts with a coarse Saburr bit (pic). The router bit wants to dig in. I doubt the Saburr bit would do that.
As a first effort, I tried to cut the blades about 3/16" fat by setting the router bit higher than the stylus. If I had more confidence in the thing, I would try 1/16" fat but my blades are thin and I didn't want to dig into them. Of course, setting the router bit high does not help when cutting the side of something, like the leading edge. That's what dry micro is for. :-(
For removing wood after most of the sawing and chopping is done, I had a 3"diameter version of this carbide wheel in the angle grinder. Worked pretty well but don't get sloppy 'cause it will really take off the wood. Then a coarse sanding disk, then the hand rasp.
Lastly, the second iteration of blade-fitting templates. Printed on the laser printer, glued to Formica sheet. The 1" offset lines can be used to check the blade angle vertically and horizontally. One prop-builder said to work the flat side to shape and to the proper angle, then gradually work down the cambered side until the templates almost touch. Spray paint and go fly! :-)
Edited by Kent Ashton, 12 May 2017 - 03:38 PM.