Stinger Review

With its 84" wingspan, our super popular, IMAA-legal Stinger kit is built for giant-scale fun. Super-strong "no-joint" plywood fuse is built-up on the bottom and features an ABS turtledeck above the wing. The giant foam wing (nearly 1,600 square inches of wing area!) features a fully-symmetrical airfoil, full-length ailerons for added maneuverability, and balsa spars for added strength. Complete plans, instructions and preformed landing gear included; 4-channel radio and 1.2 - 4.2 cu. in. engine required.

REVIEW:
Construction
The Stinger arrived in a LARGE box due to the foam wings. The kit was well packaged with the foam wing cores still in the ‘shroud’ that they were cut from. The wood throughout the kit was acceptable and none had to be replaced. The plastic (ABS) parts were accurately formed and, when cut on the scribed lines, required almost no further trimming. The canopy was very clear and defect free. All ABS parts are fiberglassed inside (I glassed the cowl inside AND out due to the anticipated vibration from the Zenoah G-62 engine I used).

Assembly of the kit progressed rapidly, and the plans were followed with only a few exceptions (noted below). The foam wing cores are covered with balsa sheeting at both the leading and trailing edges. Between these sheetings are cap strips that serve no purpose other then to support the wing covering (Monocote). The wing halves are joined with a hefty plywood spar, balsa top and bottom, then fiberglassed over the center section. I recommend putting more of a bull-nose on the leading edge of the wing than is called for in the plans. Flying proved to be too sensitive in the pitch attitude until I rounded the leading edge.

The tail grouping is made up of 3/8" square balsa sticks - no sheeting. Hardwood dowels are used at all flying wire attach points and at the control horn points. The plans call for using quick links, bending them at a 45 degree angle, then enlarging the hole to fit 2-56 hardware. These are then soldered to piano wire. There are a couple of tricks to making this happen. First, don't try to bend a sharp 45 degree angle. Just make it a nice gradual bend, otherwise the tempered steel will break. To drill the holes, use a sharp .085" drill bit and turn it slowly in your drill press, using lots of oil. You'll only be able to drill a few at a time without resharpening the bit. Also, instead of using the aluminum joiner under the fuselage to connect the flying wires together, I made a joiner out of fiberglass. This breaks up the diamond shaped flying wires electrically that can act as an RF shield to your radio antenna – VERY IMPORTANT!

NEWS FLASH!
I just changed the tail wires mentioned above. It worked fine, but seemed really heavy compared to someone else's tails section at a scale meet I attended recently. I replaced the piano wire with rigging wire. Much lighter, just as strong, and looks better.

The plans didn’t call for any fiberglass in the firewall area. I have heard from other Stinger builders that in some cases the engine actually departed company from the fuselage! Not interested in this happening to mine, I glassed the nose pretty well. I also had to make a slight modification to the firewall as I used the pitts-style Slimline muffler. Overall, the G-62 fit very nicely on this plane.

I highly recommend the wheel pant modification that was developed to insure a much more secure mounting of the wheel pants!

For the radio gear, I used my already proven JR XF-622. I put a ¼ scale servo on each aileron as recommended in the plans, and a ¼ scale servo at each elevator half. Another ¼ scale servo powered the rudder, and a standard servo for the throttle. The rudder and elevator servos were mounted in the tail. All this was powered by two separate battery packs and two switches. Redundancy in this area is a small price to pay for the added insurance. I also kept a 10" distance between the engine and all radio gear to minimize interference, and used nyrod for the throttle pushrod.

I found that the ailerons needed a 1/16" balsa sheet laminated to them in order to get the same thickness as the wing’s trailing edge. This is no big deal and I’m sure has no actual affect on flying characteristics; I just like the look of the ailerons matching the wing. I used the recommended Robart hinge points throughout. I applied a bit of Vaseline to the hinge joint, then epoxied one end in and let it set up. When cured, I applied 30 minute epoxy to the other ends and installed the surfaces, taking care to remove all excess epoxy in the joint.

Since my color scheme was black with silver trim, I wanted to canopy to blend in and used navy blue Rit dye. For those of you unfamiliar with this, just immerse the canopy in the dye at a temperature of about 150 degrees F. until the desired tint is achieved.

Flying
Well, it all comes down to this, doesn’t it? A few days after my pride and joy was finished, I carefully loaded it into the pickup and headed for the local flying field for it’s maiden flight. After running it up and taxiing it out, I lined her up with the runway and poured the coals to it. The tail lifted up nicely and executed a smooth, straight climb out. The only surprise was that down elevator was a bit sensitive. All other control responses were what was expected. I used the recommended control surface throws as indicated on the plans.

This is a very smooth flying plane with no known bad habits. It is much more graceful than the smaller birds I had been flying (this was my first stab at giant scale). The G-62, as promised by other modelers, is extremely reliable and forgiving to variables in carburetor settings, fuel tank location, etc.

All in all, this is a great plane to ease into giant scale modeling!

UPDATE - 10/2
After flying the Stinger for over a year, I decided to give it a 'lightening' overhaul.  This is amounting to a reduction of over FOUR POUNDS!  Here’s how.  I removed the following items permanently:
Spinner
Gas hatch cover
Canopy hatch
Turtle deck
Wheel pants
Cowl
Spring starter
Extra 5-cell battery
Giant scale servos
¼-20 steel wing hold down bolts

ENGINE MOD
I purchased a C&H Electronics ‘Jump Start’. This is an electronic device that allows you to hand start the G-62 without the aid of a spring starter. It just retards the spark for starting, then you disconnect the battery and go fly. The advantage of this over true electronic ignition is that you don’t have to carry the battery weight. It all adds up! Bench tests show that it’ll be great.  It's a $65 unit.

NEW WING
I'm building a whole new wing as the original wing had been through several mild crashes and it was time to experiment.  This now one is a honeycomb foam with 3/32" solid balsa sheeting.    The holes are 2 1/2" diameter - 99 holes per wing panel.  Yep, that's 198 holes in the wing!