I seem to be in a modification mood lately, but after seeing how great the FRC Su35 MK2 and the Mig29 V3 fly with some of the mods made, I decided maybe it was time to apply them to another favorite plane of mine, the F18 V3. I will probably never recycle my 300+ flight stock F18 V3 due to sentimental reasons, but after flying it and my FRC Su35 MK2, I started to think about how making some control surface mods and trying some other build techniques might tighten up it's performance even more.
So essentially I will again be going with smaller more scale size elevons. The picture below shows my new elevon compared to stock
I also have downsized the ailerons and will make them inboard, mimicking the size and location of the flaps on the F18. Since the F18 V3 is based most closely on the F18 E/F Super Hornet, that is what I drew my inspiration from when measuring and designing the new control surfaces.
I actually went out to 6" on my final mod, but forgot to take a picture of the new drawing... :/ This will make it very much the same scale size as the flaps on the real Super Hornet. Since it is a carrier based aircraft, it does have pretty big flaps. I am hoping that these will still be sufficient to give me good spoiler/flap/spoileron/flaperon input for high alpha but will maybe help reduce some wing rock at higher angles of attack. It will be fun to try out anyway!
I re-sized the rudders a bit as well, making them deeper and more inboard. I am confident they will still give me plenty of rudder authority. The hinge line at the bottom is parallel to the wing plate as in my previous F18, I find this gives good control at slow speed and high alpha.
I cut the rudder on the yellow line at the top. Initially I was going to leave the top part of the vert stab that encloses the rudder at 5/8", but was worried that might make it a bit too flimsy, so I went with 1" instead. Still considerably larger rudder than stock.
Although I know the F18 V3 will never be a speed demon since it is so weight sensitive and not conducive to large, heavy power setups, I will do whatever I can to reduce drag. The smaller elevons will help and I also plan on symmetrically shaping and sanding the leading and trailing edges on the wing/aileron, elevons and vert stab/rudders.
I will also be playing around with larger Kf airfoils. I will still go with Kf4 airfoils, paperless dollar store foam top and bottom, but they will be extended back about 1/4", this will give me about 50% Kf. Stephan Moran (sgmoran) who I worked with on many of the mods on the FRC Su35 MK2 and the Mig29 V3, has been doing considerable study on the Kf airfoils and told me that 50% is considered ideal for more straight wing planes like the F18, so I am excited to see if it makes much difference. I will also be extending the Kf forward along the leading edge root extension (LERX), another winning addition I have been liking on several of my recent planes.
I will be using the Focal Price 2700 motor with a 6x3 EMP prop, 40A ESC and will experiment with 1600 and 2200 batteries to see how they affect performance of this modified plane. I am also going to use an 8 ch receiver so that each servo gets it's own channel to maximize my ability to play with different mixes.
I want to see if it will still fly well with elevons only, so I will have ailerons switch selectable as well as playing with flaps/flaperons/spoilers/spoilerons to find the best combination for high alpha.
Anyway, I am excited to get this plane flying and see if the smaller surfaces give me that bit more tightness and precision I have been finding on other planes I have modified recently.
More fun in the future!
Cheers,
Scott
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