Thanks for the feedback Mark. Yeah I've played around with flying wings before & yeap they can be interesting to setup. I think that's why most these days are heavily swept back to improve pitch stability. I don't really want to fly a Zaggi though. I've seen plenty of planks like this, on the forums & YouTube, happily zipping around.

I must admit I'd planned to set the vertical thrust angle to 0° as this is a symmetric design. I'll do some poking around online & see what other folks are using.

As suggested I may play with the vertical fin design some more although I understand one of the odd quirks with the KFm-4 airfoil is that it can apparently be flown with no vertical stabs at all. Somehow its natively yaw stable *shrug*. Not sure I believe that but I've heard it mentioned a few times. This bird will have fins though.

Over on one of my mirror threads its been suggested that my carbon-fiber spar could be improved & have to agree. As soon as I ordered it I realized I should probably have gone with a vertically oriented spar & not horizontal. So I ordered some different spars...



One spar instead of two maybe all I need, I'll make that call once the wing is together & I can gauge its rigidity.

A few folks, not surprisingly, are wondering why I'm not just using full span elevons. The reason for that is I maybe flying this in confined areas with small landing areas. I'll need air-brakes to slow her down. If you attempt to use elevons as flaps you end up pile-driving into the ground. With a four servo wing however you can use the outboard ailerons to counter the downward pitching from the inboard "flaps". Basically mix in crow braking...



I expect it'll take some fine tuning to get the deflection angles right but from what I've seen, this is the way to stop a plank.

Okay well this is sounding good. I hope to begin construction soon. Stay tuned.