I have had the privilege in past columns to present the work of Bill Bradley. Although our last names are the same, we are not directly related. Bill does some nice small-field-compatible scale model designs.
His latest effort is the World War II Japanese Aichi D3A Val torpedo bomber. Sporting a 36-inch wingspan and a flying weight of 28 ounces, it is perfect for small fields.
Bill’s Val is covered with Polyspan and the color is satin latex paint. Bill notes that not all Vals were silver or dark green. During the summer of 1941, some Type 99 Vals were painted light gray, which is the color scheme that Bill chose for his model. The graphics were made using ink-jet-printed clear decal paper.
For power, Bill is using a Turnigy C3530-1700 motor turning a Master Airscrew 8 x 3 three-blade propeller. He notes that this is more power than necessary, but what the heck. If decent power is good, then a lot must be great!
The fuselage is planked with 1/16-inch balsa. The landing gear legs are plug-in modules. This allows them to be knocked off on hard landings to help prevent damage to the model.
Another nice feature of the aircraft is the way the plastic cowl is mounted. Rather than use rare earth magnets to hold the cowl in place, Bill set up the cowl to be a twist-on, twist-off mount. This arrangement uses three #8 pan-head screws.
Bill reports that the model flies nicely. He has teamed up with Manzano Laser Works to make kits for his Val. It is available to anyone interested in building one. The kits include formed plastic parts from Keith “Sparky” Sparks of Park Flyer Plastics. See the “Sources” listing for Manzano Laser Works.
Transitioning to Ailerons
How often have you ever wanted a relatively simple model that is not quite micro size, but is still on the small side of the small-field model spectrum? You know—a nice, comfortable flying model that can be flown in a tight space.
If you do have an interest in such a model, I have one for you to consider. This one comes from Bob Aberle and is called the Transition 75. As the name suggests, it has a 75-square-inch wing area and is intended to introduce people who are accustomed to flying rudder and elevator control models to airplanes that include ailerons.
Bob designed this model using experience gained when he designed 200-square-inch and 55-square-inch models intended to be flown in small venues. The Transition 75 has a 20-inch wingspan and a flying weight of 4.7 ounces. Power comes from an E-flite Park 180 brushless motor. It can be flown using either 250 or 450 mAh two-cell battery packs. The 250 mAh pack delivers a 5-minute flying time, while the 450 will fly for 9 minutes.
Plans for the Transition 75 appeared in the January 2014 issue of RC Micro World. Contact information is in “Sources.”
External Control Linkages
A regular contributor, John Krouse, sent me a photo of his recent project. This is a rudder/throttle control model that uses wire-cut foam-wing blanks from Bob Selman Designs.
During the model’s concept phase, John felt that an external pushrod for the rudder would simply look wrong. He decided that rather than a wood stick for the fuselage tailboom, he would use a hollow carbon tube.
The hollow carbon tube provided a nice place to hide the rudder pushrod, while still maintaining a relatively simple installation. His close-up photo shows the magnetic actuator used for the rudder control and its mounting location relative to the carbon-fiber tube tailboom. The pushrod simply passes through the tailboom to the rudder.
Although it’s not a unique idea, it is something that is easy to overlook when we set up a “simple” model. Making a little extra effort to conceal the pushrod makes a much cleaner-looking model. It also greatly helps reduce the occurrence of hangar rash. It is easy to hook an external pushrod on something when moving a model.
Nice work as always, John.
That’s it for this installment. Please let me know what you are up to in the world of small-field flying.
