Hans-Jurgen Unverferth and Reinhard Sielemann, refined the Co7 version 4 in 1995 and proceeded to dominate the German flying wing competition scene, along with Christian Behrens and Christian Tollmiens, flying the Spin Off.
The Co7's competition successes in 1997 alone were:-
Kaltenkirchen: 1st
Stoned Hill Cup: 1st
Versmold: 2nd
The Co7 is made of molded construction, but don't let that disuade you from building one out of foam and Carbon.
This aircraft has outlaunched V-Ultra's and Ellipses in a conventional launch and has easy handling characteristics. It has been punted through the F3b speed traps in less than 19 seconds with the potential to go a lot faster. It has been a winning aircraft in a large field of conventional planforms in F3j. If you are after a thermal duration wing, this is the one to buy or build.
The servos in this aircraft are the excellent JR 341's. Don't be scared to use anything of equivalent quality. Yep, thats right. It has only 4 servo's. You could even use 3 if you were creative with a flap linkage and used a strong servo. The fuselage really only serves to hold the reciever and battery pack so it can be as minimalist as you like, as long as your gear fits in. Just make it streamlined!. The antenna is a piece of music wire that protrudes from the rear of the fuselage as it needs to be kept free of the carbon.
The wing is constructed in three parts, with the location of the towhooks, 8mm behind the c.g. They are located at the ends of the centre wing panel. This gives much less load on the wing center during launch.
The spar is of carbon fibre construction and measures 24mm wide x 1.5 mm deep. It would be best to make a full mock up or drawing of the spar location to leave room for the servos. The joiner bars are 9/16" and are also carbon fiber.
I had planned to construct this model using tissue paper as a top layer over 1 layer of 190gm carbon at 45 degrees over blue foam. The tow hooks will connect to an aircraft plywood end plate which will replace the foam for the last 1/2 inch of the center section. This provides a secure attachment point and ties the skin, spars and joiner loads together.
It is important to note that the control surfaces are built with a carbon arrow tube for torsional strength. I will utilise an aluminium arrow shaft for this purpose.
If you have any questions about this model's construction, please don't hesitate to ask, but please read the construction tips first. When my version of this wing is up and flying, I will give some more feedback about what it is comparable to, but until I have the building space available, it will remain just a set of carefully cut templates and a block of blue foam insulation!
