Voltage Vulture (oz14377)

About this Plan

Voltage Vulture. Radio control electric powered sailplane, for geared 05 motor. Wingspan 76-3/4 in, wing area 635 sq in.

Quote: "Some time ago, I designed a two meter glider wing to fit the Great Planes Electro Streak (oz11911). It appeared in the January 1991 issue of RCM as the Electro-Glide (oz14374). That combination provided excellent performance and many hours of fun. The addition of a geared motor, folding prop and larger battery packs increased the rate of climb and eventually made a dedicated motor glider of that model. However, being a compromise design. it did have some shortcomings that were corrected in this, its replacement.

The Voltage Vulture was designed around the Electro-Glide wing to include some desired improvements which had accumulated over the years.

At the top of that list was my desire to have the motor battery located where it was easy to change and its mass would not destroy the fuselage in a hard landing or minor crash. It is now located so that it will eject forward through the curved sheeting on the lower part of the fuselage without destroying the nose section. As a result of its new position it can be easily changed through a hatch in the bottom without using tools or removing the wing.

Spoilers have also been added to get out of strong thermals and to descend rapidly when needed. Equipment placement and access have been greatly improved. The prop hub has increased ground clearance. Plug-in, self-locking outer wing panels detach in a hard landing or crash, helping to reduce possible damage. Detachable outer wing panels also ease storage and transport.

These changes have produced a light, tough, and durable electric glider with exceptional soaring ability.

General Construction Notes: Optimal wing loading for this design is 10 to 12 oz. per square foot. The Voltage Vulture can accommodate a variety of motors, gearboxes and up to 8-cell sub-C battery packs and still be within an acceptable weight range.

Before starting construction lay out your motor/gearbox and motor battery on the plan. Mark any desired changes in hole locations, sizes or other accommodations to fit your equipment. If you prefer right thrust, shift the large hole in F-2 3/32 in to the left of the centerline, as shown on the plan. This will yield about two degrees of right thrust.

As with any glider, wood selection and construction techniques should favor light weight. All wood is medium grade balsa, except as noted on the plan. Basswood can be substituted for spruce. 1/8 in basswood can also be substituted for plywood to laminate the wing dihedral braces. The entire model can be built using CA and CA+.

Wing: We'll start with the center panel. Use a plane and sanding block to make a 3/8 wide taper at rear of the bottom trailing edge sheet, as shown on the plan. The taper doesn't have to come to a feather edge. Its purpose is just to reduce the trailing edge thickness. Pin it in place on the plan. Elevate the bottom spar with a strip of 1/16 balsa before pinning it to the plan.

Add the ribs. The end ribs need to be perpendicular to the spars and as straight as possible to ease panel alignment later in construction. It would be a good idea to temporarily pin a straight length of 1/4 in square balsa to the end ribs during con-struction to prevent bending. Glue in the 1/8 square trailing edge fillers. Sand the fillers flush with the tops of the ribs and then glue the top trailing edge in place.

Add the top spar and all of the shear webs. Be sure that the shear webs have vertical grain and are flush with the tops and bottoms of the spars, Make the 1/16 x 5/16 leading edge from a stiff piece of balsa. Glue it in place and sand its edges flush with the ribs, then add the leading edge sheet, capstrips, center section and spoiler sheeting. Well add the end rib top center sheets later.

Remove the wing from the plan and turn it over. Install the NyRod spoiler cable guides and the 1/16 x 3/8 spoiler sheeting stiffeners. Then, add the bottom center sheeting to the end ribs (note the grain direction), the center section sheeting and all of the capstrips. All of these parts are to overlap the leading edge. Add the leading edge cap and sand it to a round section, as shown on the plan. Cut an opening in the center section bottom sheeting for your spoiler servo. Glue in the end rib stiffeners..."

Direct submission to Outerzone.

Scan by MarkD, cleanup by Circlip.

Supplementary file notes

Article.

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