I finished up an old Airtronics Oly II kit a few years ago. I used the recommendations found on the Charles River RC site. Look here.
http://www.charlesriverrc.org/articles/kitmods/peteyoung_olympiciihintstips.htm
I found most of the recommendations very valid. There are a couple of contradictions to those recommedations that I can add.
First is the fuselage fiberglassing. Don't bother with the interior fiberglassing suggested in the hints above. Round and sand the heck out of the front and mid portions of the fuse. Then apply fiberglassing to the EXTERIOR of the fuse from the nose to several inches behind the wing. DO NOT try to save weight on this plane. It flys like crap when light. My Oly has an 8 oz chunk of lead fastened to the towhook inside the fuse. It flys and thermals very well at this weight and can sort of penetrate.
With the exterior fiberglassing, forget about trying to monokote the fuse. Just sand it nice and smooth and then prime and paint. You'll probably need to sand the bare wood after the initial priming, but it will eventually provide a nice surface. Remember, saving weight is NOT the prime concern with this plane. Since you need the weight, build in strength and durability and you will be rewarded with a long lived plane that is still a thermal king.
Another thing to do is to maximize the rounding of the leading edge of the wing. The stock airfoil shows the leading edge as somewhat pointy and biased to the lower side of the wing, this adds camber to the airfoil. To improve the speed range a bit, rounding the LE as much as possible and moving the "front" of the airfoil UP by sanding more roundness on the underside of the leading edge stock. This helps reduce the camber of the airfoil.
The ENTIRE wing spar (all panels) must be fitted with shear webs. Even with this, the outer panels will have poor torsional rigidity. Forget about being able to launch this plane fast, it won't take it.
The comment above points out that hard launches will not be something that you can get away with very often. That makes carbon reinforcement of the entire spar system unnecessary. Of the dozens of planes I've designed or built over the years, the main problem with wing joiners of this type is that the bottom spar breaks right at the end of the brass joiner tubes. Another failure mode is that the joiner box splits apart. I recommend that a strip of 0.007 or 0.014 carbon laminate be glued to the underside of the bottom spar. The length of the strip only has to be twice the distance from the wing root to the end of the brass tube. This is not a question of whether the strip or length is ENOUGH, its the fact that the gluing length is limited on the inboard side. So, there is no need to extend the strip any farther that the same distance outboard.
Wrapping the spar with kevlar tow is important for preventing the joiner box splitting. Wrapping with about a 1/4 inch pitch is adequate. The wrapping only needs to extend out to at least the end of the brass tube.
With the speed increases I incorporated with my ballast and airfoil rounding, the spoilers are a must if you plan on contesting with this plane. Forget about spoiler linkages, use individual servos in the wings. The hints about suggest reducing the dihedral amount from stock. This is OK. I suggest you consult my dihedral calculator that is also located on the Charles River website. Its at:
http://www.charlesriverrc.org/articles/design/eda1.xls
The amount of reduction suggested in the construction hints above could be too much for your flying preferences.
I noticed Larry Taylor added some suggestions for the Oly II too. Most of them are sound, but the full flying stab is obviously a lot of work. The only thing that a full flying stab provides is that it is always at the proper decalage angle. The construction hints above, suggest a modification to the wing saddle angle. I found that modification to be pretty much on target. That simple modification makes any consideration of a full flying stab, moot.
Have fun with the Oly. I sure have!
Martin Brungard Tallahassee, FL "Soaring: Where screwing-up is an art"
From: "Wes Gibson" <[EMAIL PROTECTED]> Reply-To: <[EMAIL PROTECTED]> To: "RCSE" <[EMAIL PROTECTED]> Subject: [RCSE] Olympic II Modifications, Hints and Tips? Date: Wed, 31 Dec 2003 11:23:29 -0600
A friend who is new to the sport of RC Soaring, received a brand spanking
new Oly II for Christmas. Before he starts building it, are there any
recommended modifications, hints or tips that other Oly II pilots would like
to share with him? I'm guessing that some carbon fiber on the spars might
help out with winch launching. Thanks in advance for any advice.
Wes Gibson (for Kurt Rocker) AMA 607029 LSF 7533 --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.530 / Virus Database: 325 - Release Date: 10/22/03
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