Glad to see you moving along.
SAMs tips are good too.
My son lost his 120" B25 yesterday. Too bad. We think a fuel line popped off the right motor right over the field. I got part of it on my iPad video but I heard my son call out just as I heard the difference in sound. I stopped the video and watched the short rest of the flight. It went into a right hand death spiral from about 350 feet. It hit essentially straight in, in a corn field. Everybody had an opinion where it went down as it was about 1/2 mile away. Since I used to train tracking dogs i used the saying you have to know the track to train the dog. I walked almost right to it. Big mess.
Here are a couple "for what it is worth tips".
if you come out at 50# or so it will not fly like a Corsair. It will push hard in the turns. You may find using a bit of rudder helpfull. With big motors it will fly very fast. I can't guess speed but it was every bit as fast as the fighters.
We used 20-10 bolly and Menz props.
6800-7000 rpm on the ground.
we tuned the motors using matchboxes and inboard tachs in the turret. Both motors came up within 100-150 rpm from idle to max. They also would come down the same way. No engine sync. We tried them all. We had about 45# thrust available.
brakes on the mains.
very soft nose spring. This keeps the nose from bouncing on landing and takeoff. It took about 2# to push the mains down at rest so they we pretty soft too.
As a shoulder wing plane it pitched up with the flaps. Some guys use about 10% mix of down elevator. I would lobby for a Guardian from Eagle Tree
What did we learn and see from this crash? Every connector MUST have Parson locks, We probably have $75.00 worth of them, not one came off. All fuel line MUST have wire wraps on them. The one that did not, came off.
i would suggest that if you have not skinned the wing and elevator, you lay a piece of carbon fiber on top of each spar. Ours had CF on both sides. The elevator and rudders survived intact. Also I wrapped 1/4" wide CF strips around the fuselage from the top of the elevator to the leading edge of the wing opening in the fuse. 4strips total. The entire back of the fuse survived intact. I also made an internal support to make up for the side gun cut out. Again CF laminated.
All trailing edges had FG tape between the top and bottom skins. All flat hinges were giant scale with removable pins or wires then the hinged were drilled and double pinned with tooth pick material. No hinges pulled, some were torn in half with the halfs remaining in position.
None of the expensive nose and cockpit detail survived. It was too deep in the ground so we just kicked dirt over it.
3/8 AC ply fire walls survived.
i would question paper wing tubes. If you use tubes I would at least use aluminum one and consider CF. be sure to build strength all around the mounting system. I completely redesigned the wing mounting using CAD and FEA. The entire mounting on the outer panels 3 ribs and inboard of the nacelles was ripped out almost as a unit so it was stronger than the wing sections. The mains were attached to this and more or less came out with it. All 3 gear lower links broke. They were retracted so it appears that the impact caused the gear wheels to slam forward then snapped back breaking the links. Otherwise they are ok. Still attached to the bulkheads, simply tore then right out bulkhead and all.
all the radio was packed in foam as were the Lithium batteries. All were hooked up and functioning after the crash.
In the previous flights we had no real airframe problem. We did lose a main gear door the first flight. It was a project to replace it so plan the gear doors carefully and hinge them solidly.. We had 8 gear doors. The nose doors vaporized but the mains were still usable.
i built a scale functional exhaust and it survived.
Anyway don't build to crash but do consider these areas.
we are going to use the remains for airsoft target practice. There is not much left to take useful pictures of.
Every crash has a story so if I can help prevent a crash I'll try. I've been accused of being "windy" so I'll try and stay in the background.
good luck.