PHOTOS: ANNE RUMLEY
The QBIT can employ one of two engine configurations. Cox TD with fuel tank/motor mount configuration. The first configuration (above left) uses a suction carburetor fuel system. Note the rectangular firewall. The second is a
the stabilizer incidence using the 2-56 nylon adjustment screw under the stab’s trailing edge.
If the model goes straight up, rolling left, add some small amounts of right rudder. These changes must be made in small incre- ments as their effect is more pronounced at high speeds. Keep increasing the engine run by two seconds until the desired max nine seconds is achieved. Once you have the pow- er pattern and transition to your satisfac- tion, go back and retune the glide. Trim the glide to the edge of a stall by adding tail weight or shimming the motor to move the c.g. The wing may also be moved forward or aft to shift the c.g. The glide turn is adjusted by tilting the stab. When viewed from the rear, the plane will glide towards the high side. Tilting the stab also changes the incidence, which in turn affects the power pattern, so go back to us- ing the quick DT. Adding 1⁄32-inch stab tilt equals roughly 1⁄64 inch more incidence so the 2-56 nylon screw will have to be adjusted under the stab. Tightening up the glide circle will also take out some stall. An alternative—a favorite of Chuck Etherington—to stab tilt is shim- ming the wing on the wing platform with chord-length 1⁄64-inch or 1⁄32-inch plywood strips. This gives the effect of stab tilting without changing the incidence and affect- ing the power pattern.
For a more detailed guide to trimming see Don DeLoach’s “Beginning Free Flight Pow- er”, 2004 National Free Flight Society Sym- posium and “Trimming That New Model” by Terry Thorkeldsen, available on the MMM site
www.thermmmclub.com.
At this point, you’re back in the game, so dust off those old motors. You’ll love it!
Final step
If at all possible, hook up with a local group of fliers. They are key to a good pro- gression and help overcome that shyness
FLYING MODELS PHOTO: ANNE RUMLEY Ray Boyd with QBIT, a 1⁄2A-A Classic Free Flight that is perfect for getting back into freeflight. 45
Cox TD with radial mounting (above right). The pressure fuel system with bladder tank is used in this configuration which allows for a much more streamlined, sculptured nose and faster ascent.
and hesitation in flying with accomplished fliers. All local clubs are making an active effort to recognize folks who are starting or getting back into flying and are eager to help keep the hobby going. Check out “Editors Workbench”, Sept–Oct 2012, National Free Flight Digest, D. DeLoach.
Special thanks to those MMM Club mem- bers who have been so patient and helpful in getting me back into freeflight. They in- clude, but are not limited to, Don DeLoach– design aspects, Jerry Murphy–care and feed
of TDs and editing, Chuck Etherington– Power trimming-retrieving, Bill Lovins– chase bike techniques and pressure sys- tems, Marc Sisk–flying techniques and retrieving, Bill Gieskieng–trim techniques, Dave Wineland–power tips and Rick Pan- gell–pressure systems.
Laser-cut wing and stab ribs for the QBIT are available from
RamonBoyd@aol.com. Please forward any readers comments on the performance characterizes of QBIT to me at
RamonBoyd@aol.com.
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