Modeling Spoken Here - 2007/08
Nothing in the aeromodeling world is more intriguing and exciting than the sight and sound of a multiengine model airplane flying. Perhaps it's the fact that not too many of them are seen on a regular basis. More likely it's simply an acknowledgement of the effort and thinking that goes into making a "multi" work correctly.
Whatever the reason, whenever a model with more than one power source gets ready to fly, there are usually many interested spectators watching with great anticipation.
Why multiengine models appeal
In this issue we have several articles dedicated to twins. If you are considering a multiengine model, the first step will probably (and should be) a twin. Not too many will attempt a trimotor or four-engined airplane as their first foray into this realm.
Making two power sources work reliably and in unison is far more involved than making just one engine or motor work properly. Making three or more behave properly is even more of a challenge.
My new project: Ohm's Outlaw
I've always liked twins. I've sketched dozens of them through the years but have never had the time or courage to actually design and build one. That is, until recently.
With the advent of more powerful electric motor and battery combinations, a twin is far less daunting than before. Making two electric motors run together properly may not be a cinch, but it appears to be easier than getting two glow engines to operate consistently. Because of this I've started building a new electric CL aerobatics (stunt) design I've named "Ohm's Outlaw." I'll let you know how it works when it's done.
Lotsa Watts — Dick Sarpolus
One of the articles in this issue is a construction feature by the prolific Dick Sarpolus. Dick is no stranger to twins; he has produced many of them for publication through the years. Some of these were RC models and a few were for CL use.
For this new airplane Dick wanted a large twin sport/aerobatic model and he wanted it to be electric powered. The result is his Lotsa Watts design. I was honored to be asked by Dick to visit him at his home field in Monmouth County, New Jersey, and get some stick time on his behemoth twin.
Dick displayed the big twin's impressive power by pushing the throttle full on in one sudden movement. The model literally leaped into the air, and Dick proceeded to pull it into a straight-up climb, rolling it as it shot upward. I got the feeling that he could have let the model climb like that until it was a speck in the sky if he wanted to. Dick performed most of the aerobatic maneuvers effortlessly with the Lotsa Watts and then gave me a shot at the sticks. I found the model to be smooth, predictable, and easy to fly through maneuvers.
I had anticipated that a twin would have an entirely different feel and that I would have to work more to keep it tracking in maneuvers. I was surprised to find that this airplane felt just like a single-engine model in flight. I highly recommend it as a first built-up twin project.
Sport Utility Twin (SUT) — Jim Feldmann
Perhaps an easier route to getting a twin into the air quickly would be to do what Jim Feldmann did and modify an existing ARF. His Sport Utility Twin (SUT) started life as a Hobbistar 60 ARF. Jim designed nacelles and grafted them to the wing, opening up space in the main fuselage to allow the resulting model to be used as a camera airplane if desired.
The powerful SUT can also be used to tow up a glider or perhaps even a banner. Jim makes it a point to mention that other 60-size ARFs can be modified in this manner. He supplied complete plans for the Hobbistar 60 conversion, and they are now available through MA's plans service.
Tuning twins — Eric Henderson
Another article presented in this twin-theme issue is a technical piece by Eric Henderson about tuning twins, and it deals with all aspects of setting up twin glow engines for reliable operation. Eric's article focuses on proper break-in of the individual engines and getting them to be predictable in operation. Then he moves on to a step-by-step cookbook procedure for getting the engines to work together properly in a model. This section includes an in-depth section on radio programming.
Eric has done an excellent job of covering all possible aspects of twin tuning. If you are considering a glow twin setup, his article is a must-read.
Transcribed from original scans by AI. Minor OCR errors may remain.
