Waco SRE (yellow)
Pic #1 - the red/cream model is my first proof-of-concept airplane (less detailed), the all yellow is my new 2005 Indoor NATS entry.
Pic #2 - for size reference only!
Specifications:
- Over-all Wingspan: 14.1316 in.
- Wing Area: 45.31 sq.in.
- Length: 11.1286 in.
- Flying Weight: 32.0 grams
- Wing Loading: 3.58 oz./sq.ft.
Power System:
- KP00 M-20 motor
- Didel 6.6:1 Gearbox
- Selman prop adapter
- GWS 5 x 4.3 Prop
Radio Equipment:
- RFFS-100 Receiver
- Azarr M-72-Lite micro rx antenna
- John Worth micro on/off switch
- (2) Selman magnetic actuators with remote actuator inserts
- (1) 170maH LiPoly Cell
Some of you may recall back in late July when I posted some pics and info on the micro Waco SRE that I built from Dave Robelen's plans, as published in the February, 2004 issue of Micro Flight magazine. In that thread, I mentioned that I was planning to build a second, hopefully far more scale version of this fine little model. Well, I have. This second version was built from scaled factory drawings of the full-scale SRE, along with a documentation package from Bob Banka's "Aircraft Documentation" services. The full scale airplane that I chose to try and replicate was the beautiful yellow and black trimmed NC1252W SRE. I used the same scale size as the Micro Flight model (1 : 29.785 or approximately 1/30th). I used this size based on the great success I had with my first red & pale yellow version.
I quickly discovered that Dave's original plans - while quite good - were not really a true scale representation of the SRE. I also discovered that when the factory 5-view drawings were blown up to the scale mentioned, the actual airplane would be as easy to build as the less scale version. I used the same materials and general construction techniques in Dave's original plans but substituted all of the component shapes to the factory drawings and detailed photos provided in Bob Banka's documentation package. The net result is shown in the included photos.
I test flew this new model on Novemeber 18th, in an indoor basketball court/gym. I am pleased to report that it flew perfectly from the very beginning! It takes off from the groud perfectly straight and, throttled back to a little less than 1/2 throttle, it flies at a very respectable scale speed - at least visually. I was able to perform several very sweet touch and goes, a couple of nice stall turns, etc. on this first flight. The airplane has zero bad habits and feels comfortable in all attitudes. I couldn't be more pleased with this model and I look forward to trying to compete with it in 2005 at NIRAC and perhaps even the AMA Indoor Nationals in Muncie.
The model is airbrused per my earlier July thread, including the white pin-striping around all of the black trim. The bottom air dump door, the exhausts (34), the RDF antenna and the main L/G strut/fuselage fairings are .005" litho plate. The scale tandem "flying wires" are non-functional, made from .003mm CF rod (from Dave Lewis). I think these really bring the model to life. The decals were made from scanned factory artwork and include the Pratt & Whitney logo on each side of the cowl, the Hamilton-Standard logos on the prop and the Waco factory logo on each side of the fin. The NC numbers are scale in size, font and location, per the photos of the actual airplane. The prop started life as a GWS 5 x 4.3 unit. I trimmed and sculpted it to approximate scale shape and diameter - 4.75". After balancing, I airbrushed it to the colors used on the actual airplane. I made basswood male molds for the spinner and the cowl induction scoops and pulled these parts from .010" sheet plastic. I am especially happy with the spinner as it is indeed scale in diameter and shape and really looks "right" on the finished model.
The radio system is a DWE RFFS-100 receiver, Selman remote actuators, a M72-Lite antenna (totally internal), a Cloud Nine on/off switch and a single 170maH LiPo cell for power. The motor is an N-20 driving 6 : 1 Didel gears. The all-up ready to fly weight is exactly 32.4 grams.
I hope you guys enjoy the photos as much as I have enjoyed the researching, building and flying of this newest Waco SRE micro scale model. I LOVE this stuff!
Scott Christensen
