Hobby Lobby Simfly Electric Pylon-Racer-Style ARF Review

!Introduction

| spec2
| @914631
|> <b>Wingspan:</b> |< 33.8"
|> <b>Wing Area:</b> |< 250 sq. in.
|> <b>Weight:</b> |< 16 oz.
|> <b>Length:</b> |< 30"
|> <b>Wing Loading:</b> |< 9 oz/sq. ft.
|> <b>Servos:</b> |< 3
|> <b>Transmitter:</b> |< Futaba 9Z
|> <b>Receiver:</b> |< Hitec Electron 6
|> <b>Battery:</b> |< Thunder Power 3 cell 1520Mahr LiPo
|> <b>Motor:</b> |< AXI 2208/20
|> <b>ESC:</b> |< Jeti Extreme 18 amp Brushless Control
|> <b>Manufacturer:</b> |< <a href=http://www.aerotech.cz>www.aeroteck.cz</a>
|> <b>Available From:</b> |< <a href=http://www.hobby-lobby.com>www.hobby-lobby.com</a>

Hobby-Lobby's Simfly is a plane small enough to ride assembled in any car, and ready to fly even on a breezy day. Its jaw-dropping performance will wow even the "wet fuel" crowd when you take it down to the club. Turn down the rates, and it becomes a stable park flier, but you'll need a football field, or more -at least initially- to land it.

I’ve enjoyed the adrenaline rush that this category of hot, small planes so generously provides. Other electric pylon racers have offered me high-speed excitement that's been unmatched over a flat field. Unfortunately, most of these mini hotliners require a considerable area to fly in, most need a groomed landing area, and because of their tiny size but high speed flight, most are difficult to see when flying at a "safe" altitude - and they're a challenge to fly close to the ground!

For those reasons, the opportunity to acquire the Simfly intrigued me. Its larger size and light wing loading should allow me to fly this slightly tamer mini-hotliner where and when I would not dare launch one of my more aggressive mini planes. And, as you’ll read below, the Simfly’s performance will make your jaw drop, and those of any bystanders too.

!Kit Contents
@914632:The complete kit includes the wing, tail sections, and a bag of hardware.
The Simfly arrived in a plain cardboard box with all parts bagged.

When you view <a href="http://www.hobby-lobby.com/simfly.htm">Hobby-Lobby’s listing for the Simfly</a>, you’ll see yet another fantastic service from that cool company. Just below the product description is the heading, “Here’s <b>EVERYTHING</b> you’ll need”. Go with their suggestions with this plane and you will not be disappointed! That’s what I did.

They recommended, and I used, a Model Motors AXI 2208/20 brushless outrunner motor, the Jeti Advance 18 amp speed control with automatic cell type/count and cutoff, a Thunder Power 10-12C 1320 3 cell Lipo battery, MPI connectors for between the motor and speed control, a 6-3 Graupner folding prop and a Y-adaptor for the two aileron servos.

I selected three GWS Pico servos – two for the ailerons, and one for the elevator. I wanted to experiment with spoilerons because I frequently fly in confined areas and hope to increase the sink rate with spoilerons when needed, so each servo plugged into its' own channel. I used a Hitec Electron 6 receiver and a computer radio to command the whole setup. With the Y adapter, a simple three channel radio would do just fine; most pilots would prefer dual rates and expo on the elevator.

!Assembly
*Tools Needed
*Exacto Knife and blades,
*ruler,
*square,
*sandpaper,
*epoxy,
*CA,
*hinge tape,
*Velcro for affixing battery pack,
*optional Dremel Moto Tool, and
* a covering iron.

It shouldn’t be necessary to give a step by step narrative of the build, but since you're sure to want one when you're done reading this, I will cover some key points that will ensure your model will turn out fast, true, and durable.

!!Wing
@914633:<b>Mount the servo in the blocks with two screws only.</b> There isn’t room for 4, and you don't need rubber grommets. Note how the block protrudes above servo tab.
@914634:I sanded down the block, and even rounded the servo tab slightly, to avoid deforming the wing surface.

I mounted the two servos onto the included hatch covers. The blocks were already installed and drilled. The wings are very thin, so I sanded away any excess height from the blocks or else they slightly deformed the upper surface of the wing.

@914635:It's easy to see where you need to cut the film. Tack edges with the iron...
@914636:Like this!
@914637:Remember how Dennison 3-ring hole protectors worked so well from your school days? I used the same concept for the hole I cut in the center of the wing for the servo wires. I cut a ¾” circle of adhesive vinyl, stuck it down, and then cut the hole through the vinyl and covering, leaving a thin ring. Now I won’t tear the covering while connecting the wing servos to the receiver!

@914638:I cut a <b>shallow</b> notch with my Dremel (you could use an Exacto knife).
The Simfly came with strong fiberglass control horns similar to those I’ve cut from circuit boards. I found a Dremel bit similar in size to the thickness of the horn, and used that to cut a slot in the ailerons. Then I pushed the horns in, anchoring them with a drop of epoxy. CA would work too. I found the Dremel much easier and faster than using an Exacto to pick away on the aileron to make a slot.

!!Tail
@914639:<b>I trimmed the covering to expose the slots in the horizontal stab.</b> Vertical stab (fin) virtually snapped into place! I used a small square to make sure the stabs were at 90 degrees to each other.

!!!Total work time so far: 1/2 Hour

Before gluing the tail assembly to the fuse, I installed the elevator control horn just like I did for the ailerons. The instructions were very clear about this step, and helped ensure that I ended with an accurately assembled airplane.

!!Fuselage
There were just two steps to readying the fuselage: Install the elevator servo with control rod and the motor mount.

!!!Elevator Servo
The instructions called for making a servo rail from the supplied balsa stock, but I elected to glue the little servo directly to the inside of the fuselage. To pot the servo, I covered the servo with clear tape, mixed up some epoxy thickened with micro balloons and glued the servo in place, letting the epoxy ooze out the sides and the bottom - but not the top. Once the fast-acting epoxy cured, I snapped off the servo, leaving a perfectly molded pocket. Then I applied a gob of Goop to the servo and pressed it into place, confident the potted servo wouldn't break free unless I needed it to.

@914640:A view from the backside.

I installed the control rod as shown in the instructions. I ran the sheath along the ceiling of the fuse, tacking it down with a dab of epoxy an inch or so from the servo, and an inch or so from the elevator.

!!!Total work time so far: 1-1/2 Hours

!!!Motor Mount
@914641:<b>Plywood motor mount arrived already tacked in place,</b> I simply reinforced it with a bead of epoxy.

The motor mount came tacked in place. I mixed up some JB Quick Weld, and ran a bead of epoxy on the front side of the motor mount. The goal is to make the motor mount just strong enough for the torque of the brushless motor, but weak enough to break cleanly away in a crash.

!!!Total work time so far: 2 1/2 Hours

@914642:I cut cooling holes to keep from cooking the battery and motor. The wires from the AXI 2208/20 motor exit from the side of the can, and actually stick out about 1/16" through one of the holes.

!!Radio Installation
@914643:I put a strip of Velcro on the back of a Hitec Electron 6 receiver and fastened it just below the elevator servo.

!!!Total time to complete: 3 Hours!

!Final Preparation
I followed the instructions and set the elevator throw to 10mm up/7mm down, and ailerons 7mm” each way. I set these at low rates, and set high rate to be about 30% more. For the first trim flight, I wanted those extra throws just in case something was out of whack. The instructions made no mention of CG, so I calculated it to be at the spar.

!!Model Locator
@914644:<b>Tiny, but loud, the SkyKing model locator</b> will sound off when an unanticipated landing dumps this little plane in the deep grass, woods, or tall corn.
My flying site is surrounded by forest and trees, so I selected a model locator from <a href="http://www.SkyKingRCProducts.com">Sky King RC</a>. Model locators work by monitoring the pulses from the receiver, and when it detects a period of inactivity (i.e. input to the servos) it goes to work, emitting a cell-phone style ringer. Even in a tall cornfield, if you are within a couple of hundred feet of your model, you’ll find it. I’ve found you can search a large area much more rapidly relying on your ears, than having to make eye contact.

The locator is about the size of a cigarette butt and can’t weigh much more. It can plug into an empty slot in the receiver, and it also can be plugged between a servo and the receiver if there are no empty slots. SkyKing’s locator is very similar to a device previously available several years ago from Ohmark in New Zealand. The locator is far superior to a larger locator I recently purchased at my LHS because its tone varies in pitch, making it far easier to hone in on, whereas the other locator’s single-tone beep is difficult to hear over ambient noise.

!Flight Report
@914645:<b>Hobby Lobby's Simfly races out over the Mississippi River.</b> This fast plane is difficult to photo!
I connected the battery, making sure the throttle stick was fully closed. The Jeti speed control automatically sensed the battery type and cell count, and set the low voltage cutoff accordingly. I found this to be extremely convenient, because there may be times when I use a two cell Lipo when over the slope, and other times when I use an 8 or 10 cell KAN 1050 NiMh pack. Other controllers require the user to re-program the speed control manually when changing battery types or counts.

After connecting the pack, I attached the wings, double checked the moving surfaces, and gave the model a firm toss from a slight hill about 5 feet above an area with head-high weeds for a successful test glide. The plane easily flew forward and settled in the weeds.

I advanced the throttle to full, and tossed Simfly for its first real flight. The prop bit immediately with no threat of striking the ground like some smaller pylon racers, and the plane climbed smartly.

I immediately switched to low rates on the elevator, and still found it very pitch sensitive, so I noted in my mind to put in about 40% exponential for the next flight.

The plane carves well, and easily performs split S’s, Cubans, rolls, and bumps – just about any maneuver that doesn’t require a rudder. In a breeze, and with the right timing, I even got the Simfly to reliably stall turn!

With the recommended power package, there is enough power for consecutive loops. In fact, it can climb almost vertical for as long as you can see the plane. I found I could fly at full throttle for nearly 10 minutes, but that’s not really my style. I prefer to take off full throttle, climb way up and then split S for a few crowd-pleasing low passes, then perhaps throttle off, let the prop fold and cruise around for a bit. This style of varied throttle flying gave me flights of nearly 20 minutes.

!!!Stall Behavior
I tried to stall it two ways. First, I climbed to a safe height, throttled way back, and slowly fed up elevator until the plane stalled by dropping its’ nose a bit and regaining speed quickly with little altitude loss. Then I tried my best to flick (snap-roll) it. On a carving bank, I cranked the elevator. The plane just followed my input. At the worst it would mush out the turn, skidding more than carving, but remained predictable. I found no bad habits up in the air.

!!!Landing
The Simfly is a relatively slippery plane by design, so I expected it to use considerable real estate to glide in for a safe landing on its belly. I lined up the plane over the head-high grass and guided it in. I flared several feet above the weeds adding more up elevator when I could to slow it down. I won’t do that again, because just above the weeds it stalled abruptly, dropping out of the sky earlier than I expected, breaking the motor mount but causing no further damage. Thirty minutes later, repaired, I was up for another flight and for the next landing I flew the plane gently to the ground. I believe with experience I could land in a baseball park size field, but for now an area the size of a football field will do.

!How does it compare with other pylon planes?

!!Take off:
I have a Twister that requires a very hard toss, and the torque of the stalled prop rolls it hard to the left until it reaches airspeed, making every launch with my wimpy throw an adventure. But the Simfly has 250 square inches of wing area, and about half the wing loading. I just firmly toss the plane, and have plenty of time to get my thumbs on the sticks to advance the throttle.

!!Flight
The built-up wing is slightly draggier than a molded wing of some other pylon racers. For this reason, I noticed less grip in the turns when flying slow. At high speed though, the simfly tracked through the turn as if on rails.

!Is This For a Beginner?
A beginner could certainly assemble this plane with no problems, but the Simfly does require the reflexes of an intermediate or better pilot who's used to aileron control and who knows how to land a plane with a long glide.
!!Flight Video/Photo Gallery
We really wanted to get this review on line quickly, so we don't have video or in-flight shots to share - yet. Check back soon for updates and more!

!Conclusion
The Simfly is a very solid, speedy plane that can handle some wind. It’s larger than an all-out racer so it is easier to see, and I can relax more knowing I have more sky to use. It’s not as fast as a true racer either, so it will satisfy the sport pilot looking to move up to a pylon-racer style plane. I’ve even taken advantage of its folding prop, using it as an electric-assisted sloper. The Simfly will also be a very fun plane to bring out to the “wet-fuel” club, as it is fast enough to fly the pattern with everyone else.

* <b>Hits</b>
* Great design, great performance
* Excellent instructions - very few steps
* Suggested power package is ideal

* <b>Misses</b>
* CG not specified in instructions (but it's at the spar)
* Built-up wing not as aerodynamically clean as molded, but easier to repair!