AEROWORKS Edge 540T ARF

Model Airplane News, Jan 2005 by Abbe, Peter

Tear up the sky with this scale aerobat!

THE TWO-PLACE ZIVKO EDGE 540T IS POSSIBLY the hottest aerobatic machine in its class. Designed By Bill Zivko, former shop manager at Butt Rutan's Scaled Composites, it is a high-tech work of art that's crafted using the most modern methods and materials. With its modified 340hp Lycoming IO-540 engine, carbonfiber spars and all-composite wing and empennage, it is a cutting-edge aircraft with precision agility. The Aeroworks .40 Edge re-creates this world-class performance in a compact, economical ARF that can quickly be assembled into a model that's guaranteed to appeal to any hot-thumb pilot who aims to tear up the sky!

KIT CONTENTS

I didn't find any loose parts, and the model's structure wasn't damaged at all. Most of the components are made of built-up balsa and plywood; the turtle deck and hatch are balsa-sheeted foam. The highquality fiberglass cowl and wheel pants are painted at the factory to match the UltraCote-covered airframe. I spent some time with a heat gun and an iron smoothing down the covering.

The hardware package is complete and contains pushrods, clevises, control horns, fuel tank, engine mount, spinner, aluminum landing gear, tailwheel unit, wheels, wheel collars and all the necessary nuts, bolts and screws. A 12-page, photo-illustrated instruction manual and full-color photo sheet detail the model's assembly. A pilot bust and a sheet of adhesive colored decals help you to give the model a finished appearance.

* Wlng Assembling the wing is a quick and easy task. Hinge slots are already cut, and CA hinges are provided for quick aileron installation. Removing the covering from the servomount areas reveals threaded holes that are used to route the servo leads through the ribs to the center of the wing. After setting up the pushrods and control horns, join the wing halves with epoxy and a hardwood brace.

* Fuselage and tail feathers The fuselage is not difficult to assemble, but it takes time to set it up properly. The main landing gear is attached to a plywood plate in the fuselage with three steel bolts. Each wheel pant is held by a small setscrew and a large bolt that doubles as an axle. I had to enlarge the wheel pants' openings to provide enough clearance for the foam wheels and wheel collars.

The engine is mounted horizontally on an adjustable composite mount; a fiberglass exhaust deflector is already installed in the fuselage nose, and it will fit most stock 2- and 4-stroke mufflers. Although the throttle-servo tray is in the fuselage, I chose to build a plywood servo box and mount it on the firewall. This allowed me to set up the throttle linkage more easily and to balance the model without adding any additional weight.

After mounting the engine, I used the two-piece, transparent-plastic cowl to mark the positions of the required cowl cutouts. This was a quick and easy way to accurately modify the cowl to accommodate my engine. I mounted a Slimline Excel fueler on the side of the cowl and installed a Model Products Head Lock remote glow igniter. These will allow easy fueling and starting at the field.

There are plywood trays in the fuselage for the battery and receiver; glue the servo tray into place. Steel pushrods in installed nylon tubes actuate the elevator and rudder. These linkages were very tight, and they also tended to bind when at maximum control deflections.

Epoxy the fin and stabilizer into position, and hinge the control surfaces with CA hinges. It is important to refer to the colored instruction sheet to see the correct elevator-assembly sequence; if you don't, you might later have to perform minor surgery on the tail. Mounted on a plywood plate in the base of the fuselage, the tailwheel bracket is driven by the rudder.

Finishing up To finish, check the fit of the wing and the hatch, screw the plastic canopy to the hatch, apply the decals and balance the model. My Edge 540 required about 1 ounce of extra weight in the left wingtip to balance out laterally.

The recommended CG is 2.75 inches behind the wing's leading edge at approximately 25 percent of the mean aerodynamic chord (MAC); this proved to be a conservative starting point. I slowly moved the CG backwards Vfe inch at a time to 3.25 inches behind the leading edge (approximately 29 percent of MAC), and flight performance improved significantly. If you do this, be very careful. The model has a fairly small horizontal stabilizer and a moderate wing loading. Moving the CG backwards too far could quickly yield an unfriendly model!

FINAL THOUGHTS

The Aeroworks .40 Edge 54OT is a compact, economical ARF that's well suited to intermediate and advanced pilots. Its completeness and high-quality components make it a good value for anyone who wants to enter the world of scale aerobatics. Be sure to select a strong enough engine to bring out its maximum performance!

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