"Spook" can it be done?

All: Here are the rib templates that I have. The Top one is what Ron and I were going to use at first, but we thought the chord was too thick for a TD .020 engine and I thinned the chord to the bottom template. As you can see the top template is the same as the wing profile so you would have to thin the rib the thickness of the sheeting on both sides, usually 1/16 inch sheet balsa. The 2nd idea was to use a 1/4 inch triangular balsa piece for the leading edge and shape it for best wing profile and use 1/16 inch balsa sheeting on the trailing edge and shape the trailing edge as well. In the end we went with a "D" shaped leading edge and a triangular piece for the trailing edge and cut the appropriate amount off the ribs. It was easier to slot the leading and trailing edges and insert the ribs than trying to shape both leading and trailing edges to match the profile of the ribs-wing.
NOTE: On the bottom rib template the top shape is more uniform than the bottom so I would copy the top side, then turn the template over and copy the top side, now reversed, to the bottom of the ribs as you cut them. I used a jig saw to cut up to 4 sheets of ribs at a time, reversing the template each time.
   Also note a 1/8 X 1/4 slot shown on the top and bottom of the rib template. I used a 1/8 X 1/4 inch piece of spruce hardwood for wing reinforcement. A 1/8 X 1/8 inch piece could be used to save a little weight.
I also considered using lightening holes or slots in each rib, but it seemed that would make the balsa rib too weak.

 

Top rib 6 inch X 1 1/8 inch thickness, bottom rib 6 inch X 15/16 inch thickness. adjust ruler accordingly.

See above posts for other pictures of the original Spook .020 build

happydad