• Wing Span: 59 in (150 cm)
• Wing Area: 342 sq in (2210 cm²)
• Length: 30.75 in (78 cm)
• Weight: 1.4 lbs (.65 kg)
• Motor: Speed 400
• 2 Servos & ESC required

I was looking for a small electric plane that would allow me to fly from a field behind my house on evenings, or other times when there just was not enough time or daylight to load up the glow-powered planes and drive to the airfield. After looking at a number of planes, including the Multiplex Twinstar, I stumbled across the Skimmer 400 Electric Sailplane from Hobby Lobby.

This plane looked like just what I was searching for; small size, inexpensive SPEED 400 motor, light wing loading and best of all, it was on sale at the Weak Signals Toledo R/C Exhibition. Excluding the radio, I expected to be able to put the Skimmer in the air in a couple weeks for under $150.00.

The kit came well packed in a box measuring only 4" x 4" x 41". The materials were well organized, with the sticks bundled with rubber bands, and 3 bagged packages of small parts. The kit comes with most of the hardware needed to complete the model, including control horns and plastic clevises. Pushrods and hinges were not included, however.

Also included is a rolled drawing measuring 36" x 36". The instruction manual is a meager 2 1/2 page photocopied pamphlet, but did contain a listing of the contents of each small-parts bag and wood bundle, as well as diagrams of the die-cut parts. This is not a difficult plane to build, but the abbreviated instructions would leave a first time builder frustrated and scratching his head.

The quality of the wood and die-cut parts was good. The ribs were held attached to their balsa sheets by the stringer slots, which were not completely cut through. I would prefer that the cuts be complete, but at least the parts did not fall out. The few lite-ply parts were cleanly cut and punched out easily.

The fuselage is standard balsa box construction, with balsa doublers at the wing saddle, balsa longerons and lite-ply formers. Space is a little tight, especially in width, so the smaller the servos you choose, the better. A friend who has built and flown the Skimmer recommends that servos be rated for at least 11 oz. in. of torque.

The only real complication I had during construction of the fuselage was getting enough access to be able to get the battery in and out. I ended up removing the bottom half of the front fuselage former to provide enough clearance. Strength should not be compromised by this.

Wing construction comes next. Once again, the construction is pretty standard, with top and bottom hardwood spars, and 15 ribs per wing half. The wing halves are built over the plans, using 1/16" spacers under the leading edge as detailed in the instructions. 1/16" Balsa shear webs are cut and installed on the first 7 bays of each wing half. Gussets are cut from 1/16" balsa and installed in each corner of the wing halves.

The trailing edge is a tapered, pre-formed balsa strip that does not need further shaping, but it is not pre-slotted to accept the ribs. A few minutes with a razor saw took care of that. The leading edge is an unshaped 1/4" x 3/8" balsa stick that is sanded to shape after the wing panels are glued up.

The center rib of each wing half is installed at the proper dihedral angle using the supplied lite-ply dihedral angle guage. Joining the wing halves is simply a matter of laying one half flat, bracing the other wingtip up with an appropriately sized block, and epoxying the central ribs together. A lite-ply dihedral brace is then glued in place, top and bottom center sections are sheeted, and the wing joint is reinforced with the supplied fiberglass cloth. Solid balsa triangle stock wingtips are then attached and sanded to shape.

The tail surfaces are built from modeler-cut 1/8" x 3/8" balsa sticks, directly over the plan. The rudder and elevator halves are solid balsa, supplied already shaped in one of the small parts bags. The elevator halves are joined by a length of 1/8" hardwood dowel. A 1/8" x 1/8" balsa leading edge is also applied to the front of the elevator halves, which means that no cutting/shaping of the elevator halves is necessary to fit the joining dowel in place. A 1/8" x 1/8" "key" is also attached to the bottom of the vertical fin that fits into a slot in the horizontal stabilizer, easing alignment when the tail sections are attached to the plane, as well as adding strength to the joint.

Covering is straight forward, using the material of your choice. I chose Top Flite Monokote in the box art colors of red, white and blue. I find it best to cover the pieces from largest to smallest, which allows using leftovers from trimming the larger sections to cover the smaller parts. I discovered on my first couple planes that covering the small "easy" parts before getting the nerve to tackle the large, "hard" parts usually left me without enough material to cover the wings!

Trim was completed to match the box art, using my new Top Flite Smart Stripe trim stripe cutter. Wow! I do not know how I ever got along without one of those! It took only a minute or so to load the stripe cutter with Monokote, then cut perfect 1/8" and 1/4" stripes 72" long. If you do much striping, this tool is a must have.

Final assembly goes quickly, since there is little to do. The horizontal stabilizer is glued to the tail of the plane, making sure to square it to the fuselage. Then the vertical stabilizer is attached, carefully aligning it to the fuselage centerline, and making sure it is vertical to the horizontal stab. I ran a length of tape from the horizontal stabilizer edge, over the top of the vertical stabilizer, and then to the other edge of the horizontal stabilizer to hold the vertical stabilizer in alignment while the glue dried. I prefer to use 30-minute epoxy for these joints, since the strength is better than other glues, and the 30-minute cure time allows plenty of time to double-check the alignment. Make sure you remember to remove the covering from all the glued areas!

Even though not called for in the instructions, I added triangle stock braces in the corners between the vertical and horizontal stabilizers. The surface area of the glued joint is rather small, and I wanted to make sure the rudder did not fall off!

The last step of the final assembly is to install the hinges. This was the first time I used the Great Planes Slot Machine, and wow, what a difference! Cutting the hinge slots on this plane with a #11 blade would be a pain, since the tail surfaces are only 3/16" thick. Cutting the slots with the Slot Machine yielded perfect slots, and took only about 10 minutes to cut all 14 slots.

Slots were a nice tight fit, so it was a simple matter to insert all the hinges, flex the control surface to full deflection, add a couple drops of CA glue, then flex the opposite direction and repeat the process. In less than 5 minutes, both the elevator and rudder were permanently attached.

Since this is a 3-channel plane, radio installation is not too tricky. The space inside the fuselage is tight, though. I chose Dymond 200 micro servos for rudder and elevator. A friend recommended using servos with more than 11 oz./in. of torque, and the Dymond 200 servos provide about 30 oz./in. I had to use the smaller, round servo arms however, since there was not enough width for the somewhat larger "X" arms. The kit does not supply a servo mount, so I built one up out of scraps from the tail surfaces.

The kit also does not supply pushrods, so I built some up out of 2x56 threaded pushrods and some 3/16" hardwood dowel. I think the steel pushrods would have been strong enough by themselves, but a standard 12" pushrod was too short, and none of my local hobby shops had longer rods in stock. I cut each of the 12" pushrods at the appropriate place, and added a piece of hardwood dowel about 4" long. A couple "L" bends through holes in the dowel, followed by wraps of heavy thread and a couple drops of CA completed the pushrods.

I chose Great Planes Screw Lock Pushrod Connectors to attach the pushrods to the servo arms. Since this is not a high speed or high performance plane, these should provide plenty of strength, and also make adjusting the linkages inside the tight confines of the fuselage easier. I used the supplied nylon clevices, threaded onto the pushrod ends, and the supplied nylon control horns. A 1/4" length of fuel tubing stretched over the clevises keeps them secure.

I chose to use a Hitec RCD Micro 555 receiver in this plane. Its small size and light weight (0.6 oz., with case) make it a good choice for this plane. My only wish is that the servo connectors were facing the side, rather than the top. The Rx mounting tray leaves very little space between the Rx top and the wing bottom. Side-facing connectors would eliminate the need for sharp bends in the servo wires.

There is plenty of space under the Rx tray for installing the battery. I chose a Sanyo 7-cell 500 mAh AR pack for this plane. The only problem I encountered was that there was not enough space in the front fuselage former to get the battery pack through. Luckily, I checked this while assembling the fuse, and it was a simple matter to cut the bottom half of the former out. Since the fuselage bottom is sheeted with balsa, I do not think there will be any problems with this. There is ample room to move the pack fore and aft to adjust the C/G balance point to that specified in the plans. After locating the battery for C/G, I glued in a stop block behind the battery, and used dense foam to wedge in the battery at the front.

The motor mounts in the nose with a couple machine screws through the nose block. I had to replace the screws supplied with the motor with longer screws. I also added flat washers to provide more support for the lite-ply up front. The speed control fits in the cavernous space under the front hatch. I used a Jeti JES 110 electronic speed controller with BEC. Weighing in at only 4 grams (wires included), this microprocessor controller will handle 6 - 10 cells, and is rated at 11 amps continuous.

After getting the Skimmer finished and the batteries charged, I had to wait almost 2 weeks for weather suitable for a maiden voyage. Finally, a nice sunny day with light winds presented itself, so I loaded up the car and headed to the field.

Before the first flight, I set the C/G balance to the plan specs. I tried a couple power-off tosses to verify the balance. I felt a little nose heavy, so I moved the battery back about 1/4", and powered it up!

The first flight was exciting - it was my first of the year, and, because it is so much smaller and lighter than my glow-powered airplanes, the Skimmer felt very twitchy and sensitive. But after a few minutes, and with a little altitude, we both smoothed out a little. Two clicks of right trim were dialed in, and 2 clicks of down trim were added to keep the nose down as the plane climbed.

Stalls were gentle, but tended to roll off to one side or the other, rather than straight ahead. The Skimmer stalls at moderate speed, so you need to make sure to keep the nose down, especially when landing. Landing was not difficult, as long as you do not slow the plane down too much.

All in all, the Skimmer flew very well. With a couple more flights, I am sure that this will be a very enjoyable plane to fly.