Radio Control: Helicopters
BLADE BALANCING TECHNIQUES: In a previous column, I discussed how to find and eliminate vibration in our model helicopters. Although there are many possible sources of vibration, one of the biggest has to be the main rotor system-specifically the main rotor blades. A better way to balance the main rotor blades will not only reduce the helicopter's vibration, but the helicopter will fly better. Actually, blade balancing theory is fairly simple (see Figure 1). Just three things are needed: 1) the blades must be level on a balancer, 2) the spanwise CGs must be the same, and 3) their weights must be the same. However-and this is very important-if any two of the above requirements are met, the third will automatically follow. We can't fool Mother Nature.
Radio Control: Helicopters
TSURUGI: a new name in helicopters. Hirobo has been synonymous with helicopters for many years, and may be best associated with their long line of successful .30-size Shuttle series of helicopters distributed by Altech Marketing. Although Hirobo has produced many larger helicopters, the Tsurugi is their ultimate RC frame (vs. scale) helicopter that is a culmination of all their design and development efforts. The first paragraph of Hirobo's instruction manual states that the Tsurugi was designed so "anyone can operate it to make the most of its performance." This is a very impressive statement to me, because it means the Tsurugi was designed with the stability and ruggedness required by the novice flier as well as the top-of-the-line quality and flight performance for the FAI flier. I believe they have accomplished both objectives. The design of the Tsurugi shows that Hirobo has really done its homework and given us virtually all the features we could want in a helicopter.
Radio Control: Helicopters
ONE OF THE MOST frustrating aspects of our hobby is getting the vibration out of our helicopters. Although some causes of vibration are hard to find, I always try to remember (in the middle of my frustration) that there is a definite engineering cause. All I have to do is play Dick Tracy and find the part of the helicopter that is causing the trouble. Then the cure is easy. The first cure for vibration is to build your helicopter exactly according to the instructions, taking time with each step to ensure it is done right. Because some people can't wait to get their machines in the air, they rush through the building process. This is where many causes of vibration can be "built out."
Radio Control: Helicopters
A NEW HELICOPTER PUBLICATION called Model Helicopter Technique (4926 Verdura Ave., Lakewood, CA 90712-3018) has recently hit the streets and is being published by Ray Hostetler. To give us the most helicopter information for Ray's publishing dollar, this quarterly publication is printed on black and white stock paper and is bound with staples. I'm really impressed with the attitude of the magazine-cutting down on the frills and beefing up the informative and interesting articles helps all classes of fliers. I hope you all give this publication your support, because we are the ones who will benefit in the long run. One of the MHT articles is a pilot profile: Curtis Youngblood responds to Ray's questions. Although I have never met Curtis or even seen him fly (except in videos), I'm impressed with his basically stock X-Cell and his down-to-earth attitude of relying on the basic helicopter.
Radio Control: Helicopters
IN THE LAST ISSUE, I presented some safety checks for your helicopter after a winter's rest. However, one area I didn't discuss in detail is the proper care and feeding of Ni-Cd batteries, which continue to be the weak link in our radio systems. Battery technology is virtually unchanged for the past several years, and there continue to be different points of view on battery technology, even among the experts.
