Does anybody have a copy of the Strega ARF trim video? I have watched the Strega ARF videos series numbering 742-749 and thru out the Strega ARF series Windy said he intended to make a dedicated Strega ARF trim video. He also said he had accumulated 40 pages of notes and data for a "Control Line World" article. Does anybody know which "Control Line World" issue contains the article?
I am not aware of Windy doing anything like that, but it's certainly possible.
After having helped construct and flying an ARF Strega, there's not a large number of special tricks required. There are only a few problems that I would consider mandatory to fix, other than that, the issues are with the design that cannot be easily corrected, and short of buliding a new airplane from scratch, aren't practical to solve. At least in the Strega, the controls are usable as is, which puts it way ahead of the ARF Nobler, for example.
Close off the back end of the tank compartment to keep stray fuel out of the rest of the fuselage. Just about anything will do, use 1/16" balsa attached to the rear of the former.
One of the issues is the fit of the belly pan to the wing and bulkhead (the F2 former). As it came, the kit I worked on had a belly pan that did not quite fit flush with the bottom of the fuse. Trim the airfoil section of the belly pan until it fits flush with the bottom. There will very likely be a gap at both the front and the back. Strip the front face of the belly pan, and the rear face of F2 including any covering and any epoxy or other glue until you have bare wood on both sides. Tack the belly pan in position, and then carefully fit a wedge of end-grain balsa to fill the gap precisely. This is relatively easy to do with a bandsaw, but can be done with hand tools if necessary. The goal is to fill the gap perfectly with the grain running fore and aft. Then do the same with the rear/angled end of the belly pan, but instead of the end grain, install 1/8" palsa doublers/joiners on the inside faces of the fuselage that extend across the diagonal cut and glue to that. When installing, use lots of epoxy to fill up the end grain. Of course, do this BEFORE you fit up the tail, so you can align it to a rigid fuselage.
It goes without saying, but I will say it anyway - of course you need to remove any covering or glue around the wing saddle top and bottom, on both the fuselage and the wing. Go very careful about stripping the covering on the wing. it would be very tempting to grab an Exacto knife or razor blade and slice it chordwise - but don't, because you will also cut into the sheeting. Lay the edge of the blade flat against the covering where you want to cut, then pull the covering up and that will cut it.
The only other change is to round of the leading edge of the wing. Strip the covering for about an inch either side. The leading edge is 1/4 square on edge and some sort of hardwood, with the balsa sheeting lapped over it. You cannot go much past 1/4" from the existing "point". Mark a line 1/4" behind the point with a ball-point, top and bottom. Then using some sort of coarse sandpaper on a block, or a Perma-Grit file, sand the leading edge flat until you have a vertical flat surface 3/16" wide from root to tip. The exact dimension is not critical but it does need to be the same from root to tip on both the inboard and outboard. Mark a line right down the center of the flat. Then round off the corners until you have a nice even radius from the pen mark to the centerline mark, leaving both in place but leaving no flat spot at the LE, it should be nice and round. Smooth it out with fine sandpaper. Then cover it with something like more heat-shrink (color optional...) or sticky Monokote to seal it up
The latter is to prevent the wing from stalling in hard maneuvering. You can leave it alone, but you will be sorry on the first hot day. If you can fly it without stalling, you are probably are flying way too big!
Note also that this is a BIG model with macho-man drag and requires a macho-man engine. I wouldn't use anything smaller/weaker than an ST60. Maybe a Saito 56 but you will have to thrash it within an inch of its life. Forget the ST51 or any lesser engine.
Trim is conventional, no surprises. You will never get it to fly like a more modern design like an Impact, but if your forearm is strong enough it will fly reasonably well. The changes above will take you a few hours at most, which is still a heck of a lot easier than building the entire airplane from scratch!
Brett
Topic: Strega ARF Trim video and Strega ARF in "Control Line World" written by Windy? (Read 3937 times)