Fred,

you cannot imagine how helpful your messege is. I am an engineer and I have built several planes from scratch but this is my first "major" modification. Even so, you just nailed the main problems I will face and even venture some answers. Many thanks!!

I have though about setting the retract servo upside down but I have to see the plane if there is enough room. I have a retract sevo but it has some years and is very thick. That is why I was asking about regular servos but I scratch that out. I will get a new thinner servo and try to work it out (either upright or upside down) to have a direct link to the retracts. I rather have a direct connection between the servo and the retracts as using linkages may jeopardize everything. What I see is that I will have to "tilt" the retracts so the wheels will be located well beyond the CG once the landing gear is deployed.

Referring to the wheel diameter, I do not want to use very small wheels as I usually fly from a concrete strip but my landings are still "rough on the edges" (need to say that the plane is for my son, he really does great landings, "most of the time"). I did think about using regular size wheels and cutting the leading edge and enlarge the root of the wing to fit the larger wheel (like the wing of a P51) but I will decide it once I get started to study the airframe.

The wing joint is critical, I am considering using dual servo for aileron and using the wing servo bay for flaps (if I dare modify the plane that much). In either case, the retract servo has to be mounted closer to the main spar so a new servo bay has to be fitted. I wil have to consider the wing joint ("small" thing I just have not thought about it. Thanks for bringing it up!)

Your pictures are very helpful and clarify most of my doubts. I hope I can be posting my own pretty soon and I will tell you how things go.

Take care
Carlos