Wight Wizard (oz11820)

About this Plan

Wight Wizard. Radio control sport aerobatic model, for .20 power.

Quote: "Keith Humber updates his successful 'Wight Witch' aerobat for .19 to .25 engines and four channel R/C.

Wight Wizard has been designed as a follow-up model to my Wight Witch (oz11668) - it has the same wing and tail group as the Witch, but the fuselage is quite a bit different. The modifications are as follows:

1. The nose is shortened by approximately 1/2 in. This saves the small amount of lead that the previous model carried in her tail.

2. I have mounted the engine in side-winder fashion. Our field can be a bit dusty and it's easy to ingest too much dust with an inverted engine.

3. The tank hatch is now litho-plate on the top front bay half-section.

4. The fuselage is now doubled with 1/16 ply from F2 back to the wing trailing edge, with no other framework. This seems quite adequately strong.

5. There is now only one rear fuselage former at the halfway position and the rear fuselage is slimmed down in depth, with a 1/8 planked turtle decking.

6. The front wing mount dowels are now two in number, rather than the one on the Witch, which gives a bit more security and a stiffer wing mounting.

7. I also reshaped the lower corner of the rudder in to a curve rather than a sharp angle, to save hangar rash.

All the modifications are small, but born from experience and hopefully take the 'Wight Witch' theme further. Not that the Witch was a bad model - she was very good, but I think that the Wight Wizard is just that bit better. At least the Wizard has come out a bit lighter!

The model certainly flies well with no vices and, on an O.S. 25 FP, offers a magical performance. The Witch was a super flying model but needed a ballraced 25 to get the same performance. So I suppose the Wizard must be better.

Both models are very manoeuvrable. The inverted flicks at the top of a vertical climb are a joy to behold, very like a full-size Extra or Sukhoi. And all on a cooking 25! So, on to a brief description of the construction.

Fuselage: The fuselage is 1/8 sheet basic construction. Two basic sides are cut from 1/8 sheet doubled with 1/16 ply glued with contact adhesive or white glue. The formers F1, F2, F3, F4, F5, F6, are all 1/8 ply with 5/8 x 1/2 in beech engine bearers. The bearers are chamfered in the tank bay to enable the rounded edges of an MFA 4oz rectangular tank to fit in place. The bearers are glued to F2-F3 with epoxy and the basic sides are framed up with the same glue. There is 1/8 balsa tail seating glued as a doubler to increase the gluing width for the tailplane. Fit the rest of the formers, pulling in the rear fuselage and gluing with epoxy.

The tail group is made from 1/4 in sheet fixed with epoxy at this stage. The undercarriage mountings are made from hardwood and installed well glued. Then the fuselage bottom 1/8 sheet is fixed into position. The pushrods are 16swg with 1/4 x 1/4 balsa bound to the wire and installed into the fuselage before the top 1/8 planking; it's easier to thread them through. The rear fuselage turtle decking is 1/8 planking carved and sanded to a smooth contour.

The ply wing mount is curved on the front edge to enable the servo mounting screws to be accessed - OK but tight. Here mini servos could be used but both my models used normal sized units. The engine is now bolted into position to enable the silencer cut-outs to be accurately cut. The cowling is blocked in around the engine with 1/2 in sheet carved to shape. The tank hatch is made from litho-plate, bent with a rebated top edge which hooks under the 1/8 fuselage top planking and is retained at the bottom edge with two 1/2 in screws. You could easily make the hatch out of balsa; I just happened to have some litho-plate handy.

The canopy fairing is just a 1/8 balsa planked fairing on three liteply formers. Do check that the servo arms and pushrods clear inside the fairing, or use a mini servo if you have one available. The fairing is retained in position with a screw at the rear and turn-buttons at the front.

The wing: The wing is framed up on 1/4 x 1/8 spruce spars. built flat on the plan, ie.no dihedral. One 36 in length in one piece - simple isn't it! The 1/8 sheet outline tips make it up to 40 in span. I used 3/8 sheet leading and trailing edges, with 1/16 sheet 'D' boxes and 1/4 x 1/16 cap strips. And that's all there is to the basic wing.

The ailerons are carved from 3/8 sheet with commercial torque rod horns and hinged with Mylar tape. There is a small 3/8 sheet fixed fairing on the fuselage to protect these horns. I must remind you to be careful - do make a good job of the wing mount dowels and the retaining bolts, etc., as you will probably be pulling quite a bit of G forces with this model.

My prototype is covered with Solartex, painted with Humbrol enamel and, finally, Tufcote fuelproofer.

Airborne! Flying-wise, she has no vices. My thick reflexed symmetrical wing section is really quite forgiving but will snap manoeuvre with the best of them. Recommended control movements are as follows: aileron 1/4 in up, 1/4 down; elevators 3/8 in up, 3/8 down; rudder 1 in either way. At these settings, with the CG as shown, she should be quite lively on the ailerons but fairly soft on the elevator.

So why not try the Wight Wizard? No Black Magic with this one! "

Direct submission to Outerzone.

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