I have been thinking of converting my old slightly battered F-16 (it did end up in 3 pieces) into a delta out of curiosity.I have never attempted to scratch build in this fashion before, so i would like some ideas on what sort of airfoil section to use and how to work out the CG. I will probably cut them from foam. I would imagine it would end up looking similar to Herb's latest effort which looks great btw.I could try the section shown on Herb's plan on his post i suppose (if you dont mind!).How would you reduce the section at the tip to still have any thickness (stupid question?)

Greetings -

You can cut the foam cores for a delta by cutting from a pivot point, using just one airfoil template at the root. If you happen to have back issues of Flying Models handy, Ivan Munninghof showed how to do this in detail for a little Speed 400 prop powered delta model. The airfoil on Herb's drawing looks fine and you can also use a symmetrical section and just reflex the elevons a bit. Maybe a bit more drag than the airfoil on the plans but the end results would be close to the same. You might also want to go to the NASA/ Dryden web site and take a look at the photos and drawing for the F-16XL which is essentially what you're wanting to do. The cranked wing planform may be a bit easier for you to duplicate too. Look at: http://www.dfrc.nasa.gov/gallery/photo/index.html

Another place to look is at the Electric Jet Factory web site and compare the Flying Styro F-16 to the version of the XL that EJF developed based on that kit.

Be sure to get your CG right!

Fly Fast! Mark