[Headline: Sig Manufacturing Co. Somethin’ Xtra EG ARF]
[Subhead: A classic sport model revisited]
[Author: Geoff Barber]
[Photos by the author]
[Sidebars in this file]
[Video for the tablet and online]
Model type: Sport aerobatic ARF
Skill level: Intermediate builder; intermediate pilot
Wingspan: 51.5 inches
Wing area: 725 square inches
Wing loading: 16 to 17.6 ounces per square foot
Length: 48.25 inches
Recommended power system: .40 to .46 two-stroke or .53 to .65 four-stroke engine; 700 to 1,000-watt brushless outrunner motor (550 to 800 Kv); 75-amp ESC; and 4S to 6S 3,000 to 4,000 mAh LiPo battery for electric power
Radio: Minimum four-channel transmitter and receiver; four standard servos (five for glow power)
Minimum flying area: Club field
Street price: $199.99
Power system: O.S. Engines .46AX two-stroke glow engine; five Hitec HS-485HB Deluxe HD Ball Bearing Standard Servos
Radio system: Hitec Optic 6 Sport six-channel 2.4 GHz transmitter; Hitec Optima 6 six-channel 2.4 GHz receiver; 4.8-volt Ni-MH receiver battery
Propeller: Graupner 11 x 7 nylon propeller
Ready-to-fly weight: 5 to 5.5 pounds
Flight duration: 10 to 12 minutes
• Sig EG Series is suitable for electric or glow power.
• Two-piece wing design for easy transportation.
• Magnetic hatch for easy battery/radio compartment access.
• Sturdy aluminum landing gear.
• Painted fiberglass cowl and wheel pants (cowl optional for electric version).
• Complete hardware package included.
• Comprehensive, fully illustrated instruction manual.
• None noted.
Sig Manufacturing Co. is a name that everyone in the aeromodeling hobby should know. In fact, Sig celebrated 60 years in business in 2014! With such a long-standing commitment to model airplanes, it’s no wonder that the company continually develops great new products.
Sometimes a new product can be a remake of an earlier aircraft—that’s where the Somethin’ Xtra enters the story. This aircraft has been around the block a time or two. It’s still available as a kit, and was previously in Sig’s lineup as an Almost Ready to Fly (ARF) aircraft.
At the 2014 Toledo R/C Expo, Sig unveiled a new version of its classic airframe: the Somethin’ Xtra EG. The EG signifies that the new version can be powered by either electric or glow power. With the ever-growing number of modelers who enjoy electric flight, the Somethin’ Xtra is getting yet another go-around!
Before beginning any assembly, I like to read through the manual. Sig has some of the best-written and illustrated manuals in the industry!
Assembly began with tightening the covering on all of the parts. There were few wrinkles in the covering, so this was a quick task. With the covering tightened, I attached a 6-inch servo extension to each of the aileron servos and installed them in the wing. With the servos in place, I installed the ailerons using CA hinges and thin CA glue.
To properly center each hinge, a pair of T-pins was inserted in each hinge before it went into the wing’s trailing edge and the aileron. With the hinges centered, the T-pins were removed and thin CA was applied to each side of each hinge. Control horns and pushrods were assembled and installed next, and presented no issues.
I set the completed wing halves aside and moved on to the fuselage. The first task to complete was assembling and installing the main landing gear. The axles were attached, along with wheel collars and wheels, before sliding the wheel pants in place. With the main gear assembled, it was attached to the fuselage with three socket-head screws and a few drops of Zap Z-42 thread-locking compound.
I moved on to the tail surfaces, and began installing the elevator hinges. The same technique I used for the ailerons was employed for the elevator hinges. The elevator control horn was installed before attaching the horizontal stabilizer to the fuselage.
I fastened the wing halves to the fuselage, and set the stabilizer in place to check for proper alignment. I mixed a batch of 30-minute epoxy to attach the horizontal stabilizer. I had enough epoxy (and time) left over, so I attached the vertical stabilizer at the same time.
After the epoxy cured, the rudder was attached in the same manner as the elevator and ailerons, and the rudder control horn was installed.
The rudder and elevator servos easily slipped into place. Although the fuselage is narrow, it’s well laid out, making installing the electronics a breeze. I assembled the elevator and rudder pushrods and slid them into the guide tubes at the tail and connected to their respective control horns.
With the rudder and elevator servos centered, the pushrods were marked and bent to length. The excess was removed with a wire cutter. The pushrods were attached to the servo arms and retained with a pair of snap keepers.
The O.S. .46AX two-stroke glow engine installation was straightforward. One item of note is that the engine mounting bolts were not included with the kit. Sig’s reasoning is that not all engines use the same size bolts, so the modeler must acquire the correct bolts, washers, and nuts. This was not an issue for me because I have plenty of hardware in my shop.
The throttle servo and pushrod were easy to install. With the engine, throttle servo, and pushrod in place, I assembled and installed the fuel tank. I had some Du-Bro green nitro fuel tubing on hand that nearly matched the green covering. Standard nitro fuel tubing would work fine, but the green looked sharp!
All that remained was to mount the pilot figure, attach the canopy to the magnetic hatch, and install the receiver, battery, and switch. With these final steps complete, I checked the center of gravity (CG). The CG was perfect, so I charged the 4.8-volt Ni-MH receiver battery. The Somethin’ Xtra EG was ready for its first flight!
Some modelers may prefer to assemble the airplane throughout the course of a few nights, but I assembled this one in approximately 11 hours on a Saturday. It was a good thing that I did because the weather was nice on Sunday. I called my buddy, Jim Buzzeo, and headed for the flying field!
The wind was from the west, blowing at roughly 10 mph for the maiden flight, and the temperature was hovering in the mid-70s. It was a beautiful day to be at the field!
The O.S. .46AX was well broken in, so I was able to concentrate on the airplane without worrying that the engine would quit. I slowly advanced the throttle, and the Somethin’ Xtra EG began rolling down the runway.
The airplane lifted off at approximately 3/4 throttle and was climbing out at a decent pace! I couldn’t help but give it a roll while climbing out. Even on the first takeoff it was apparent that this airplane was going to be a lot of fun!
During a quick jaunt across the field to make trim adjustments, one click of up-elevator and two clicks of right aileron were all that were required for straight-and-level flight.
Fast or slow, the Somethin’ Xtra EG didn’t care—it just flew, and it flew well! I was surprised by how fast the airplane could move with its fat wing. The wing is so thick that it looks like a huge magnet for drag! Surprisingly, I found that the airplane could cover the length of the field in a matter of seconds.
At the other end of the throttle stick, I was impressed by how well the Somethin’ Xtra EG flew at slow speeds. I could keep the aircraft in the air at 1/4 throttle by gently pulling back a little on the right stick. It just kept flying!
I pulled the throttle back to idle to check the stall characteristics. When the wing finally stalled, the nose dropped straight ahead. I added some throttle, pulled back on the right stick, and the airplane was flying again.
It was time for some aerobatics! On low rates, the Somethin’ Xtra EG is fun and can perform graceful aerobatics. Loops were big and round thanks to the engine’s abundant power. Rolls were axial and fast, but manageable. Stall turns and knife-edge flight proved easy thanks to the rudder’s large surface area.
Overall, the Somethin’ Xtra EG is a great sport airplane for performing any aerobatic maneuvers! Flipping the switch to high rates was like changing the airplane from Dr. Jekyll to Mr. Hyde! The Somethin’ Xtra EG became a true aerobatic monster!
Everything the airplane did on high rates was faster, snappier, or just plain ridiculously insane! Rolls were almost too fast to count, and loops could be tight. Remember to slow the airplane before twisting it on high rates.
Because I already knew how slowly the airplane flew, I felt at ease when approaching for my first landing. The ailerons were effective, and never gave a hint of losing control. The Somethin’ Xtra EG touched down easily, and slowed to a stop in the grass. With that, the maiden flight ended.
For this review, I pulled an O.S. .46AX engine out of my favorite aircraft. The engine has found a new home, and won’t be moving back!
I enjoyed the Sig Manufacturing Co. Somethin’ Xtra EG. The manual was easy to read and comprehend, assembly was quick and easy, and it was a blast to fly! Fast, slow, or mild-to-wild aerobatics, the Somethin’ Xtra EG can handle it!
Sig Manufacturing Co. is a great company that’s been around for six decades. Here’s to another six![dingbat]
Sig Manufacturing Co.