Hi Hugh,
I didn't get a notice on the update on this topic...sorry for answering so late...
For the small blades I do not use a drawing knife except for the root section. For bigger blades I definitively do use both, drawing knife for the root section and roughing out the leading edge and manual plane for the lee side of the trailing edge. A power plane is a tool that just doesn't work for me, whatever I do with it, it will destroy everything but I have about 30 different manual planers to choose from ;-)
...call me mad... :-D
I have recently made a Set of Blades with 3m diameter using my method. I did make the blade thicker there, especially on the tip section where it is about 11 mm thick. The wood blank was 20x6 cm laminated wood which is an easy to get standard size over here and when you buy it, it is already plane on all 4 sides.
I do not quite get your argument about the highest point of the airfoil...
I did cut through one of my test blades to see the different sections....it all looks good.
I now have my blades drawn in a CAD program so I can choose exactly where the highest point of the airfoil has to be on the different sections. and I leave about 1mm of space to get a nice round shape when connecting leading and trailing edge an still have the right thickness.
I do not see any difference to your airfoil shape concerning that. With your way you get the 2 sides parallel, mark the 1/3 line and work down from that section. In my case that line is the highest point from the beginning on the bottom of the blank wood. In the end the angles and the shape of the airfoil are identical to yours. Of course it is not quite correct the way I did it in the video. The way I marked the 1/3 line there is not really correct. In my CAD program I now did measure that point from the windward side and corrected the distance that has to be taken on the Lee-side. This is probably what you meant and you were right with that referring to the video.
Also using your numbers for thickness and drop for my method does not exactly give the same results on the final airfoil shape. I adjusted for that for another test blade and it then worked out correctly. I now have kind of my own design.
If you like, I can post the dimensions for the marks on leading and trailing edge for my 3m diameter prop here. There everything is correct concerning the angles and the highest point of the airfoil.
In the end everybody has his own style of doing it. For me, this way of carving blades is by far faster.
I have now made stencils for marking all the lines and I do make all 3 blades the same time....step by step to increase accuracy and processing speed. This way I can make a complete set of 3 1.5 m blades in about 6-8 hours, depending on how many people come by to disturb me ;-)
ps. My nickname is menelaOs and not MenelaUs...its a little funny as a "Laus" in german language is that kind of bug that lives in peoples hair... :-D
Max
Also I now only use 3 Stations, one at the root, one in the middle and one for the tip, I feel that this is enough