A 20" wingspan aerobatic sport flier with a KF variant wing

This design was started in November of 2007, and first flown with the 9 gram motor in December of 2007; After the motor was upgraded to a "16 gram" motor, this web page was started in December of 2008, and last updated on December 9th, 2008. Thanks for visiting!

The Spinner 20 is flying at 6-3/8 ounces in December of 2008. It features a Kline-Fogleman variant wing design, with the top step at 50% of chord, and an extensively heat-shaped wing leading edge airfoil.

In the photo above, you see it in it's latest flying form; I replaced the smaller 9 gram motor with an ~18 gram motor, which gave it the power it needed to perform superbly! I'm flying an APC 6x5.5 propeller on this motor, and flying a 3S 620 mAH battery pack. The above photos also show the larger 2-9/16" GWS foam wheels which give a bit more prop to ground clearance.

The SPINNER 20 is somewhat based as a scaled-down version of my very successful 30" wingspan SPINNER, which I designed in November of 2004. It is also partially inspired by the 'Shark Bait' design. It has a wing, tailgroup, and upper fuselage which is built of Bluecor fanfold foam, while the under-fuselage is made from EPP. It features very lightweight landing gear made from 2mm CF rod, and employs wing tip plates.

The battery is carried within the EPP foam fuselage, directly on the center line of the wingspan, to keep the aircraft balanced. This enclosed battery compartment is shown in the photo below. This also keeps the battery warm during winter flying sessions, which is necessary for good battery performance.

The photos below show the smaller 9 gram motor mounted with it's GWS 6x3 propeller; the 6mm motor mount fits the bearing tube on both the 9 gram and '16 gram' motors, so the motor swap-out was easy. (This aircraft was flown with the smaller 2"white plastic GWS wheels shown in these photos previously.)


Wingspan = 20"

Overall Length (without motor): 17.2"

Horizontal Stabilizer span: 13"

3 HXT500 servos

Corona RS410 receiver

~18 gram brushless motor

2" GWS light plastic wheels

Motor: "16 gram" brushless

ESC: Turnigy Plush 10A

Battery : 3S HXT 620 mAH LiPoly

Propeller: APC 6x5.5 electric prop

[Below:] This is the completed airframe after all of the edges had been feat-formed. I particularly spent a lot of time shaping and forming the leading edge of the wing.

The counter-balanced elevator gives smooth control response while minimizing the load on the modest size servo.

[Above:] Bottom view, with landing gear temporarily taped in place. The forward fuselage belly was extended after this by adding more EPP foam to give more prop clearance for the 6" props.

For information on a somewhat similar 18" wingspan design, the Shark Bait, CLICK HERE to visit the discussion thread on RC Groups. My postings begin on page 8, post 119.

Click here to jump to Bruce Stenulson's main RC Flight page

This web site and all of the digital photos and other original materials found here are subject to protection under the Copyright laws; All rights are reserved by Bruce K. Stenulson, P.O. Box 69, Fairplay CO. (c) 2004-2008. Permission is granted to link to this web site or to it's individual pages, but not to reproduce any materials found here for other than personal, non-commercial use. My intention is to maintain the context within which this material has been presented.Thanks for your understanding.