This item is discontinued.

A lot of people have asked me what inspired my E-Giles. Well, it was fun to turn heads at the 1998 IMAC nationals flying a 40-sized ARF; so why not Electric for 2000? The idea occurred to me in Maryland last fall at a fly-in. I had a wonderful chat with Derek Woodward, an electric pilot who was enamored by Michael's GP CAP 232 and was telling me how he was going to convert one to electric. He talked to me at length about the power the MaxCim's provide, and the idea struck home. If the MaxCim was a good choice for the 40-sized CAP, it should be a great choice for the soon-to-be-released .46 sized Great Planes Giles G-202 — with its larger wing area, wider fuselage, but not significant increase in weight. The Giles should be a perfect home for this electric wonder!

A few emails and a phone call later, MaxCim shipped a system, followed shortly by the recommended MEC Solderless Power Tube with 20 matched Sanyo SCRC2000 batteries. You see, being new at this electric thing, I found someone who knows the equipment, then trust them to give you provide exactly what's needed—and try not to second guess them. And boy did they get it right! One unique feature I'd like to point out was the in-line fuse which is required to allow power to the speed control — pull the fuse and there's no chance the motor can start. The fuse is mounted out the side of the aircraft and is removed for safety. (Please see the side bar for specific details of the equipment on board the E-Giles.)

Shooting for the Moon—Identical Take-off Weights

The first challenge was to match the take-off weight for the E-Giles as the O.S. FS91P-powered Giles prototype. A pre-production kit, meant to check parts fit, easily doubled as the foundation for the E-Giles. Because of the lesser vibrations of the electric, ribs were safely hand-cut 1/16" contest grade wood, rather than the conventional 3/32" die-cut grade wood used in the kit. The four full-span webs that make this wing's design unique were cut from hand-selected contest grade wood. The wood and the use of two mini servos resulted in 8 oz. of savings — the E-Giles wing weighs just 16-1/2 oz., whereas the prototype's wing weighs 24! This was a great start toward the desired take off weight. (Author's note: The modifications made to this aircraft were made after careful analysis of the differences in stress placed on a model between glow and electric power. None of these modifications are recommended for a glow powered aircraft.)

The fuselage was next. Nothing was changed in the primary box, counting on the weight change in the wing to balance the battery weight. The tank tray was replaced with a flat, reinforced ply plate which served as both speed control mount on top (inside the front deck) and battery mount below. The twin tubed batteries were strapped securely to the tray, with ply formers or supports on all sides to hold the batteries in place in the event of a hard landing.

A single layer of the normally-laminated firewall was used, with large holes cut in it to properly ventilate the speed control and the batteries, and the huge lightening hole in the aft fuse bottom was left uncovered to allow plenty of air exit to ensure proper cooling of this powerful combination. A hand-pulled butyrate cowl added to the uniqueness and made the electric motor visible.

The stock engine mount was tossed in a drawer, replaced with a wrapped, cylindrical motor mount extension from 1/32" birch ply to support the motor on its round mount and distance it properly from the firewall. This mount extension consists of 1/32" ply wrapped into a tube to match the motor mount's size, with 1/8" ply plates in the front and rear edges of the tube. The round metal MaxCim motor mount is secured with threaded rod through the mounting holes, through the front ply plate, the back ply plate and, finally into blind nuts, securing the whole combination to the E-Giles.

The stock Giles requires a rear-mounted rudder servo for proper balance with all engines except the lightest, so we (incorrectly) assumed that the weight of the electric power combination would require the rear mounted servo as well. Additionally, we opted for the heavier Ohio SuperStar tail gear on the model because of its long tail wheel positioning in case Michael would do "harrier landings" and similar 3D tricks with the aircraft.

It was time for the radio and electric equipment to get installed. The BEC speed control eliminates the need for a receiver battery pack (a second version of the speed control is available non-BEC which can handle up to 25 cells instead of the 21 cells). The safety fuse mentioned above is mounted out the fuselage side. An AstroFlight Zero Loss connector is mounted out the fuse side as well, for proper charging with the AstroFlight 112D charger, and the provided switch is mounted out the other side of the fuse (due to lead lengths). That's it, the electric power is all on board!

When it came time to check balance, it was a wake-up call. This new generation of high performance electric must be recognized as a very light motor and speed control up front, combined with a lot of ballast (batteries) that are positioned to set the model's C.G. After completion, the rudder servo had to be moved forward to aid in balance.

Was the goal met? It certainly was! The stock FS91P-powered prototype weighs in at 6 lbs 4 oz dry. The E-Giles weighs 6 lb. 5 oz.! Not only is the landing weight nearly identical, but the take off weight is lighter!

The Moment Of Truth — Flying the E-Giles

It took us a while to get to fly her the first time. There were new things to learn — like a DC/DC charger doesn't get enough punch from an inexpensive AC/DC converter to properly charge 20 SCRC2000 cells. A few calls to AstroFlight and some other tests on our charger, showed there was nothing wrong with the charger — and then the right question was asked — what was the power supply to the charger? Switching from the converter to a spare car battery solved the charging problems, and she's ready to fly!

There's just nothing quite like the sound of an electric motor whispering down the runway. To this day, I swear you could hear my knees knocking as Michael lifted off! The E-Giles lifted off beautifully, executed a procedure turn, and was flying by center stage at a beautifully quiet whisper in no time. On the 14 x 6 APC, she had enough power for fairly tall verticals, and for the coolest tail slide I've ever seen! But not enough to torque roll. At 5 minutes, he landed her to check everything over and talk about the first flight.

There were new lessons to learn—the incredible mass of the batteries had two major effects on the aircraft. It gave the desired positive effect: decreased roll inertia. Wow, does it roll! The model has less mass in the wings so it starts and stops rolls, snaps and spins more easily than the stock model. It also had a mild negative effect not expected: a much higher vertical C.G., resulting in a less stable and more tail-heavy feel. After moving the C.G. forward slightly to compensate, and making log notes that a future E-Giles would benefit from a slight increase in dihedral and in positioning the batteries as split square packs with one down on the gear rails, she was again ready to fly.

A search for more vertical from the aircraft, resulted in another call to Tom at MaxCim. (All the while thinking, "This man should be tired of hearing from me by now!") Tom happily discussed performance, and the differences between the desires of a competitive IMAC pilot (looking for lots of vertical performance) vs. the more typical momentum style flying of sport pilots. He recommended experimenting with props, being careful to not draw over 60 amps and ideally keeping it around 35 amps as its typical current draw, especially if its going to spend a lot of time at full throttle. Since she will normally only see full throttle for going up vertically, he confirmed 35-40 amps should be a safe range, and it was time to find a prop that would give that kind of loading with as much vertical pull as possible. A handful of props purchased and an afternoon testing, showed that an APC 16 x 8 would pull 38 amps during its first 3 minutes of run time and, at one minute into the run, was making 8-1/2 lbs of static thrust! While static thrust isn't much use for telling how an airplane will fly in most situations, it's a great indicator of whether or not the model has enough power to hang on the prop and do torque rolls. At 8-1/2 lbs, she has a full 2 lbs more thrust than her flying weight, or a 1.3:1 power:weight ratio — enough to torque roll!

The next time the weather permitted, the E-Giles was off to the field. I could hardly contain my excitement! Check the voltage, turn on TX, RX, and plug in the fuse, and she's ready to fly! She floated down the runway, picking up speed, and was in the air and climbing with authority. I was utterly thrilled. After a trim pass, Michael brought her in from the right and right there, dead center, he pulled her vertical and performed an absolutely gorgeous torque roll! He let her fall off into a stall turn, brought her back into center stage, and flew the 1998 IMAC sportsman routine. The aircraft handled the entire sequence with ease and with power to spare. Knife edge passes confirmed that the dihedral should've been increased and/or mass shifted to match the glow Giles' vertical C.G. (the stock Giles has no roll coupling on rudder; the E-Giles exhibited a small but noticeable amount.)

A fistful of flights later, I couldn't be happier with the E-Giles' flight performance. She looks great, sounds incredible, and a few percent of rudder-to-aileron mix later, flies flawlessly. She's capable of showing off with torque rolls and the other impressive things Michael can do, but more important to me, it's an impressive flier for my style of flying, sportsman level IMAC competition. It snaps brilliantly, with no hesitation on entry and no over-rotation whatsoever on exit (I love low roll inertia!) It absolutely loves to fly inverted, with barely a breath of down elevator required. The presence of this aircraft in the sky is so impressive — it looks, feels and flies like it's much larger — and add to that its near silence, it's just a joy to fly.

Conclusions:

So what do I think? I'm in love with my new E-Giles! It was a fun, exciting, unique project to build, and is great fun to fly. Thanks to Derek Woodward the inspiration and to Tom Cimato at MaxCim for all his support and patience. Oh yes, and of course, to the test-pilot/supporter/designer who made it possible — Michael.

If We Did This Again?

If something should happen to my E-Giles, with Michael's support, I would undoubtedly replace her with another. And here are a few thoughts of what we'd do differently:

Battery accessibility: My one "thumbs down" on this electric project is inaccessibility of the batteries. A battery pack change requires removal of the wings and a bit of "shoe horning" to get the pack in and out. Michael would redesign the front deck so the pack could go in and out through a removable top hatch.

Vertical balance and mass: One way to resolve the vertical C.G. issue be split square packs. Set one of the packs down on the gear rails, which is a very structural part of this fuselage. Then, center the second pack C.G. This would return the aircraft to the slightly more stable feel of the glow Giles and get rid of the need for a rudder-to-aileron mix for knife edge.

Lighter Fuselage: The fuselage was not modified at all except to accommodate the electric's equipment. A future bird could be lightened somewhat in the tail area of the fuselage structure, enlarging lightening holes to leave 1/4" around the edges to help avoid the tail heavy problem and lighten the flying weight even further. The rudder servo would be stock mounted up front and the standard G.P. tail gear used for the tail wheel, again saving weight and helping balance.

All in all, she's a real pleasure to fly! I would recommend this combination to anyone looking for a fabulous flying, quiet, easy-to-maintain aerobat. "Look ma, no glow fuel residue!"

Materials used in preparing this article are available from the mfg.'s listed below:

Great Planes Model Manufacturers, P.O. Box 9021, Champaign, IL 61825-9021, 217-398-8970, http://www.greatplanes.com/

Stan's Fibertech, 2575 Jackson, Riverside, CA 92503, (909) 352-4758, http://members.aol.com/Bigdude007/stanstech.htm

MaxCim Motors, Inc., 57 Hawthorne Dr., Orchard Park, NY 14127-1958, (716)662-5651

Model Electronics Corp. (MEC), 14550 - 20th Avenue NE, Seattle, WA 98155, (206)440-5772

APC Propellers, Landing Products, 1222 Harter Ave, Woodland, CA 95776, (530) 661-0399

Ohio RC Models, 30 West Linden Ave., Miamisburg, OH 45342, (937) 859-1660

The Electric Power System Propelling the "E-Giles" G-202

The motor system in the E-Giles was provided by MaxCim Motors. It begins with their MaxN32-13Y Brushless DC Motor which is designed to power planes from 10 cells to 25 cells and beyond. This was supplied with a Model Electronics, Inc. "Superbox" gearbox fitted with a 3.33:1 ratio, a recently introduced 1/4" output shaft and prop adapter, and the MaxCim the G96307-1 Motor Mount Kit (this is the mount that bolts through the extension onto the firewall and the motor clamps to it.)

Also provided was the Max 35C-21 Digital Brushless Speed Controller which has a rating of 7-21 cells and will provide 35 amps continuous and up to 65 Amps for 30 seconds when needed. It also has the optional on-board 3 amp/5V BEC (Battery-Eliminator-Circuit) that drives the receiver and up to six standard servos. We connected the BEC between the two 10 cell battery tubes to stay within the BEC's 14-cell limit. Also included was the optional "Remote-LED" which is a handy setup/diagnostics light emitting diode on an 8" cable that can be mounted on the surface of the model for ready reference to the health of the controller and the state of the received signal from the radio. Also used in this installation was the prewired "Sermos Fuse Holder with SPST arming switch". Being fully assembled and with connectors already in place, it is a "plug-n-play" assembly. We chose to provide current from 20 hand selected, matched SCRC2000 NiCd batteries in a pair of MEC Solderless battery tubes. The cells simply slide into the tubes and the tubes are capped shut and bolted down for easy cell access and service. While slightly heavier than a soldered pack, they were again "plug and play" and made the process and installation easier for a newbie like me.

NOTE: This same motor system can be configured to fly planes from Quickie 500's with direct drive and 10 cells to 10-12 lb. sport and scale warbirds with 20-25 cells. It's plug and play simplicity made this project possible for me, and its reliability, versatility, and performance make it a great choice for any electric project in its size range.

Additional Photos