ASSEMBLY NOTES

Click HERE for a PDF of the templates needed to build this kit.

BOOM: ½” x ¼” x 22½”, the underside tapered to 1/8” at the tail.

POD: 4½” length of 18mm body tube; balsa nose of your choice; ¼” x 1” exhaust port cut in the bottom of the pod, just behind the nose shoulder. Coat the entire interior of the pod—forward of the motor—with epoxy. Composite motor ejection charges are pretty...enthusiastic...and will utterly destroy an unprotected tube.

GENERAL ASSEMBLY:

--Construction of the wing and stab are the same: draw the pattern onto the balsa, flip the pattern over on the centerline, and draw the other half. Cut the piece out as a single unit, draw the centerline (and polyhedral cut lines), flip the piece over and draw the airfoil high point line. Airfoil as a single unit.

--Once the wing is airfoiled, flip over and carefully cut apart at the polyhedral lines. Bevel the joints and re-glue the wingtip panels with 2” dihedral under each wingtip.

--Glue the horizontal stab flush with the rear of the boom, FLAT SIDE DOWN. This glider uses a lifting airfoil on the stab. When gluing it, do not glue the last inch of the stab down. When the glue is dry, slip a ¼” wide by 3/32” high wedge of balsa between the rear of the stab and the boom to give it some decalage, and glue the wedge in place. [Yes, I know, it seems dumb to put decalage into a lifting airfoil, but for some reason it works!]

--Glue the rudder to the bottom of the boom, flush with the rear. MAKE SURE THE HORIZONTAL STAB AND RUDDER ARE EXACTLY PERPENDICULAR WHILE THEY DRY. Fillet all joints.

--Glue the pylon to the top of the boom flush with the front edge, MAKING SURE IT IS PERPENDICULAR TO THE HORIZONTAL STABILIZER. Cut two rectangular ¾” by 1¼” plates from 1/64” plywood and glue one to each side of the pylon/boom joint to reinforce it (just in case).

--Glue the wing to the boom with the leading edge butted right up to the pylon. MAKE CERTAIN THE WING IS LEVEL WITH THE STAB AND STRAIGHT ON ITS CENTERLINE ON THE BOOM. When dry, fillet all joints (including the polyhedral joints).

--Glue the pod tube to the pylon with its rear flush with the rear of the pylon root (in other words, the tube should not hang out over the angled rear of the pylon. If you do this before gluing the nose in, you can sight down the inside of the tube to assure perfect pod/boom alignment. THIS ALIGNMENT IS OF SUPREME IMPORTANCE! IF YOU’RE GOING TO SCREW UP A STEP, DON’T MAKE IT THIS ONE!

--Glue the pod nose on, glue a launch lug to one side of the pod/pylon joint, and fillet all joints that haven’t already been filleted.

NOTE: The Mediocre Fred design is pretty beefy, so you don’t need to tissue the wing as long as you are flying it on D3 motors. If you are planning on using a stronger, higher-thrust motor, I’d suggest tissuing the wing.

The only other streamlining I did on the prototype was to sand the front of the boom to the same angle as the pylon leading edge. Rounding the pylon/boom leading edge will certainly improve its drag profile, and hollowing the nose will reduce the amount of balancing clay needed. I suspect it would also be okay to sand the boom to a teardrop profile to reduce weight, but see the “What To Expect” notes below before taking that step.

--PUT SOME COLOR ON THIS GLIDER!!! Make the lower surfaces black and the upper surfaces a nice bright color that you won’t find on the flying field. Put a band of the opposing color on each surface (i.e. a black band on the upper surface of the wing and a bright band on the underside of the wing). If you’re flying competition, don’t forget your NAR number. You can use this on the upper wing instead of a band of black.

--TRIMMING: Friction-fit a spent D3 casing in the pod, with the rear of the wide part flush with the rear of the tube and only the nozzle sticking out. Add clay to the tail (in the stab/rudder joint) of the glider until it the CG is roughly 7/16” forward of the rear of the wing. Take the model outside to a nice, soft landing field to glide test it.

With normal gliders you test them with a gentle, nose-down toss from shoulder level. Not so this glider. Hold it under the wing, take a couple of running steps into the wind, and give it a good, hard heave upward at about a 45-degree angle. In all probability it will roll inverted and start to dive. It should, however, right itself and settle into a very gentle glide. If it stalls remove a bit of clay from the tail; if it dives, add some clay. UNTIL YOU ARE FAMILIAR WITH THE FLIGHT PROFILE I SUGGEST TRIMMING IT TO A SLIGHT STALL.

--FLYING: Prepping is soooooo easy! Just friction-fit a D3-3 motor (just as you did when trimming), pop in an igniter, and launch just as you would any other glider. Make sure, of course, that your launch rig has a way of keeping the clips from grabbing the tail.

--WHAT TO EXPECT: I wish I’d gotten an altitude track on this thing, because it gets waaaay the heck up there! On its maiden flight the prototype Mediocre Fred boosted very straight, making a few vertical barrel rolls during ascent (probably due to a slight rudder or wing misalignment). Since the model transitions from boost to glide during motor burn there will be virtually nothing to signal motor ejection. You really have to have good eyes to follow this thing. A properly trimmed MedFred will glide for over five minutes, so take that into account regarding how far downwind it will drift. It won’t weathercock at all during boost.

--WHY IT WORKS: I have no idea. Call it magic.

--ADVANTAGES: The competitive advantages of a no-moving-parts Rocket Glider are pretty clear. With a good design, it’s easier to build and trim. It’s a lot easier to prep. It’s more reliable, since the only things that can go wrong would be the motor ejecting (unlikely unless you forget to friction-fit it well) and the motor shutting down in mid-burn. With no hooks, hinges, elastics or strings, it’s a much cleaner aerodynamic design. Drag is minimized, translating into higher altitude and longer glide duration. And...here’s the best part...if you’re flying in relatively troublesome breezes, you can angle the launcher upwind so Mediocre Fred drifts back over the field. Try that with a slide-wing or slide-pod glider and you’ll have a transition failure do to high airspeed.

--QUESTIONS?

E-mail: kwickart@cyberianet.com

Phone: (309) 862-2263

Post: Kevin Wickart

1700 N. School #129

Normal, IL 61761