The Spektrum AR6400 brick receiver revisited
Byline
Paul Bradley | [email protected]
THE SPEKTRUM AR6400 Series: Indoors or out in the wild blue? When the ParkZone Cessna RTF model was introduced, the world of smaller RC model airplanes was forever changed. That neat little package included the early Spektrum micro-brick receiver.
It was not long before enterprising builders began to extract the Cessna receiver and power system for scratch-built or converted lightweight FF models. Thankfully, Spektrum began selling the receiver/ESC/servo brick as a stand-alone item. It has evolved since that first model and has become the heart of many small-field/indoor projects.
For many, the choice of an AR6400 series brick system has been for indoor flying. That trend is shifting somewhat. Although the early RTF models using the system were probably best flown indoors, manufacturers are offering more models that can be flown outdoors. The AR6400 has been refined to create a broad application environment for smaller models.
The revolution of the AR6400 series brick system has made the world of design and build-your-own small-field models much richer. The AR6400 has inspired other manufacturers to develop compatible offerings that work well for indoor models but are also great for the smaller outdoor model aircraft. To wet your whistle a bit, here are some projects from two regular contributors to this column.
Gordon Johnson’s Pitts
Gordon Johnson has developed an outdoor small-field Pitts. It is a profile foam model with several nice refinements. A Spektrum-compatible receiver from Deltang, available from Bob Selman Designs, controls his creation. The receiver is compatible with the ParkZone servos used with the AR6400.
Gordon’s Pitts has a 19-inch wingspan. The wings are wire-cut foam from FlyingFoam.com and are a departure from the more typical flat-plate type seen on many small profile-foam models. These wings use a Clark Y airfoil, which contributes to flying performance and provides more strength. Along with the Deltang receiver and ParkZone servos, Gordon used a Mighty Midget brushless motor driven by a two-cell 250 mAh LiPo battery pack. The all-up flying weight is 91 grams, and Gordon reports the model is a great outdoor small-field flyer.
John Krouse’s climb-and-glide model
John Krouse has developed a fine small-field climb-and-glide model. It powers up to a comfortable altitude; when the motor is shut down, the flight transitions to a glide. This is a great way to enjoy some thermal hunting within the confines of a small field.
The model is all balsa and features a 26-inch span, single-surface wing. All controls are handled by an AR6400 brick system. The built-in ESC drives a 7mm Super Slick brushed motor that is coupled with a Gary Jones 4:1 gear drive turning a GWS 5030 propeller. The equipment source is BSD. The energy source is a single 160 mAh LiPo cell. Total flying weight is 48 grams. John says the model is stable, responsive, and fun to fly, and that the fun factor really ramps up after the power is cut and you encounter a passing thermal.
These two projects show what is possible with the AR6400 and related systems for outdoor small-field models.
General-aviation scale models for small fields
I’d like to address general-aviation-based small-field scale models. Full-scale GA designs often translate very well into great model airplanes.
A good friend to small-field flying, Pat Tritle, has created a line of GA-based model airplane kits. He has recently added a new one to his lineup: the Series 170. That aircraft is a classic and is one many full-scale airplane owners and pilots admire. As typical of a Pat Tritle design, it is light for its size. At 1:8 scale it falls on the larger side of the small-field spectrum. The wingspan is slightly less than 54 inches, yet the flying weight is only 23 ounces—another example of a light but larger-size model.
Control functions include throttle, rudder, elevator, ailerons, and flaps—a complete control package. Power for Pat's prototype comes from a Suppo 2217 (950 Kv) brushless motor turning an APC 10x5 propeller. Two 2,000 mAh LiPo cells comprise the battery pack. Pat notes the flying qualities are excellent, with good response to the flaps; the model is stable and docile, yet responsive and positive on the controls. Short kits are available.
RC Micro World (plans resource)
A great plans resource for small-field flyers is RC Micro World (RCMW). That publication was started by the late—and significant—contributor John Worth. John passed away in late 2011 and will be missed. Fortunately, he arranged to keep RCMW operating by transferring operations to Roland Friestad, so this valuable resource can continue.
RCMW has been going through some delivery changes; Roland has worked through the online issues and they are now resolved. A nice feature is you can view all issues for free, though there is an annual subscription fee to access full-size plans.
I’ve included a couple of photos of Bob Aberle's 200-square-inch Anderson Pylon. Full-size plans for that model and many others that are perfect small-field flyers are available for download with a paid subscription.
Specifications for Bob Aberle’s Anderson Pylon:
- Reduced from the original 1937 90-inch span to 36 inches
- Wing area: 200 square inches
- Flying weight: 7 ounces
- Power: eFlite Park 250 brushless motor
- Battery: two-cell 800 mAh LiPo pack
Comet designs revisited
I want to revisit Comet designs as scaled-up small-field flyers. I received feedback about my October 2011 column: reader Al Hieger liked Pat Tritle's scaled-up Comet Gull II and pointed out other Comet designs that would be good candidates for similar treatment—Sparky and Phantom Fury, for example. I can vouch for those designs. Pat Tritle has a 55-inch short kit available for the Sparky, and I have seen Phantom Fury done in a similar size range.
Al is right: the old Comet designs make great RC small-field flyers when scaled up. Perhaps one of you will take on such a project and share it with the rest of us.
Don't be bashful about sharing your latest project. My contact information is in the Sources listing below.
MA
Sources:
- Bob Selman Designs
(417) 358-9521 www.bsdmicrorc.com
- Pat's Custom Models
(505) 296-4511 www.patscustom-models.com
- RC Micro World / Roland Friestad
1640 N. Kellogg St. Galesburg, IL 61401 [email protected]
- Paul Bradley
10201 Scarlet Oak Dr. Independence, KY 41051 [email protected] www.parmodels.com
- FlyingFoam.com
(512) 670-2107 www.flyingfoam.com
Transcribed from original scans by AI. Minor OCR errors may remain.
