RE: Turbine Enforcer
Randy,
Looks good. FWIW here's my two cents worth:
Concern 1: You shouldn't have any flutter problem with the elevons. I have heard of some having issues with the fins. The 3/16" stock that comes with the kit is too thin. I made fins out of 1/4" balsa on my DF and put triangle stock at the base to stiffen them up. This is a 150 mph plane and I've never had a flutter problem. For the Turbine Enforcer I made the fins out of 5/16" balsa.
Concern 2: I extended my nose by 6 inches and needed to move the CG about 1" forward of the plan location. The plane is very stable at that location. Joe Lupton had the same experience with his.
Concern 3: That will be fine, you just need a slight amount of nose up. Measure the distance from the ground to the center of the LE near the fuse. As long as that is greater than the distance of the center of the TE off of the ground you're OK.
Decision 1: Canards are really personal preference. You don't really need them unless you extend the nose a lot more than 6". If you install functional canards you will have better pitch control, but won't need it unless you're doing abrupt maneuvers.
Decision 2: My DF Enforcer slows down just fine with a little bit of nose up AOA. I started building my Turbine without one, but later added a speed brake to the bottom based on advise I got earlier in this thread. The rationale is that the higher idle thrust of the turbine may make the plane harder to slow down. I'll see how much good it does once I start flying this bird.
Decision 4 (What happened to 3?): Fin shape doesn't matter much. Whatever looks best. The bigger they are and the farther apart they are the more stability they add. The size of the movable rudders doesn't matter much either (within reason) unless you are planning on doing some knife edge flying.
On this model I think fin tips are mainly for appearance. I'm planning on putting them on my turbine version and extending them down to double as wing skids to protect the linkages.
Don't worry about flight characteristics. A lot of Enforcers have been the victim of major kit bashing and they all fly well. It's a very forgiving airframe. The important thing is to get your CG right (err on the side of slightly nose heavy for your first flight), and make sure you have the right amount of reflex in your control surfaces, as shown on the plans.
A good source for color scheme ideas is to search pictures of recent jet meets and check out all of the sport deltas: Kangaroo, Hot Spot, Rookie, Blade, Stingray, etc.
I strongly recommend that you do something about the former just in front of your turbine. Angle it forward and lower it if you can. A flat surface like that moving through the air will create a vacuum right at your turbine inlet affecting the engine operation. Check out my pictures in posts 38, 40, and 1 (DF) to see how I did it. Also if you notice the other turbines in this thread they have all made modifications to insure adequate airflow the the engine. Moving your turbine a bit aft would also help.
Good luck,
Joe