Do #4 almost done, I'm using CF tape & tubing in critical areas, hoping it will stay together if I ever touch down again while hovering in a strong cross wind. Not that I plan on doing that again, but CF adds little weight for the strength . This build was easy since I didnt take the engine off the mounts, just had to screw it on with muffler & mounts all attached. I also had all the pushrods from #3 plus receiver & wires,tank, ect.,all pre-assembled. I didnt even open up the manual for this build. I kept the battery from the X100, its a 2500 mah Nimh 4.8V pack, going to see how that effects 3-D, I forgot why I pulled it from the X100 & put in 6V. Will find out-again. I added a tad more right thrust & up. My last Do really pulled left hard in Harriers & RH,had to use full rudder(momentarily) just to keep it straight. Its amazing how different models handle in 3-D. The rudder on the Velox is extremely touchy in harriers, on the Do, it barely has the control necessary. If all goes well, I'll have 2 or 3 planes ready for the next club fly-in,camp over,bad boy weekend in 2 weeks.