Hey Balsa Brain, Third time into RC, eh? Well, this is my second time. I had to interrupt the upper wing assembly for a couple of days, as I found that my table had some "flatness" problems. I ended up buying a "REALLY FLAT" hollow core birch door, cutting my table down a bit, and rebuilding it. I glued a sheet of Homesote to the top of the door and now I feel confident that it is a good building surface. I had to straighten three of the four spars, which are now ready for assembly. I have all the ribs placed on the spars ready for gluing. I was able to acquire some L angle aluminum from a window installer and made up about 30, 3/4x1 1/2 right angles for rib positioners. I drilled a 1/16" hole in the short leg for pinning to the board, then use a small spring loaded clamp to hold it to the rib. That way I can set everything up straight ready for the CA. I also made two spacers for placing the ribs the same distance apart. I found by measuring between the ribs, that they are not all equal. So if you gang cut and sand the shear webs, they won't fit.
I also just recently read a great article in RC Report by Bruce Tharpe of BTE, about the different grades and weights of balsa. He had some great tips about placing the heavier balsa parts closer to the center of the wing or forward in the fuselage.
Thanks for the heads up on the tank. You know the most time consuming part of building for me is the "thinking and planning ". I look things over and try to plan ahead on what I want to do. I know a couple of our club members who just fly through the building process, because they are familiar with a certain plane. This P90 is just aching to be modified. So every change has to be thought through, since it will effect anther part.
I have enjoyed working on this plane, and partidipating in this forum. I have had some great insights from modelers who have share with us.
How are you positioning your engine? On it's side, inverted? How about a muffler? Smoke?
Thanks again,
Loren