Precisely when the prayer call from the nearby mosque woke me up, the door opened, and three person barged into my room. My wife, usually would still be sound asleep beside me, carried some lit candles, apparently mounted on a small cake, my son with a large box, and my daughter the photographer with her camera. They sang happy birthday. It was my birthday.
Last night, when I was frustrated trying to reroute some pipes that apparently collide with each other when pasted from another drawing, they left for the mall, with a promise to bring me dinner. Dinner came alright, and I worked late into the night. Well, not only did they buy dinner for me, but also a helicopter. An electric toy helicopter as a present on my birthday that I have forgotten. I have been busy with my autocad.
It was the idea of my son (we call him kaka) , who happened to know that I am interrested in machines that can fly, toys included. And my daughter (we call her ade) was also concerned that I had been spending too much time in front of my computer for the past week, and thought I needed a distraction. So they conspired to give me some pleasant problem, and here it is, a SHUANG MA model 9116 electric helicopter with 4 channel radio control.
I was delighted, because this helicopter is close enough to the real one in terms of flight controls. Well, not really, but it was far more realistic than the super mini helicopter made in China with twin coaxial main rotors you can find in almost every mall nowdays. I was actually far more concerned than delighted, because I know flying this toy would require a certain amount of training, at least self training, if I want to keep the machine intact after the first flying attemp. But I liked it. It was exactly as ade had intended. A pleasant distraction.
“Kaka, is this a helicopter with a swash plate? It’s got only one rotor”.
“Yes,dad, threre’s the swash plate. You must be very careful with this, it can go wild”.
“I don’t have any licence to fly a helicopter”.
“No need for a licence, but here is the training materials. Ade downloaded this last night”, kaka said while handing me a seven page instructions written by Radd. It was written in 2011.
“O my God, ade made me a cadet in an online flying school”.
This kind of toy has been around for quite some time now. But I am sure back in 2011 the toy would be somewhat simpler than this one.
Time to study the remote control. It’s microprocessor controlled, with complicated setting procedures. There’s a large LCD panel to monitor the setting and adjustment. It has two joysticks, each with two trimmer switches, one switch to reduce all control ranges (wide or narrow, how wide or how narrow you can configure), and four other buttons (menu, select, up and down). It is a fully digital unit with spread spectrum (frequency hopping) radio. Back in 1986, spread spectrum communications was one of my friends thesis. The theory was full of mathematical formulas with a lot of trigonometry and Fourier transforms. It’s all in a toy now.
Then ade gave me some instructions.
“Follow the instructions carefully, dad. Don’t skip any step. You must be very diciplined to fly safely”.
“But it is only a toy, ade”.
“Yes, but an expensive one, and you can hurt yourself and people with it. Please be responsible”.
I can only agree. She is a graduate of HSE studies.
A real helicopter has throttle, collective handle, rear rotor pedals, and flight stick control. Throttle is set to a predefined RPM of the engine. A governor maintain the RPM througout the flight. The engine is a stationary engine, like a generator set. You manipulate the collective to ascend and descend, the pedal to control to which direction you are facing, and the stick to determine to which side (front, back, left, right, or a combination of them) you are flying. Sounds easy, but you need several semesters of flight training to be able to do it without killing youself.
The collective lever and the flying stick control the same thing, the swash plate. While the flying stick moves the swash plate in two horizontal axis ( say, x and y) the way you want it, the collective moves the swash plate vertically (z axis), changing the angle of attack of the rotor blades. SHUANG MA 9116 does not have collective. Its rotor has a fixed angle of attack. Ascent and descent are controlled directly by the throttle (rpm of the motor). This makes it tricky.
Same situation with the tail rotor. In a real helicopter, the tail rotor is driven by the same engine as the main rotor, through a long drive shaft. You control the angle of attack of the tail rotor blades using the foot pedals. SHUANG MA has another motor driving this propeller, which speed is controlled by the position of your rudder stick. Amazingly, this little machine has a gyro control on this tail rotor, which means its speed is automatically determined by this gyro to keep the chopper heading to one direction, unless you move the rudder stick.
According to Radd’s instruction, I will have to spend the first charge of the battery just to run the rotor at low speed, no flying yet, and try to maintain the position of the chopper within a box of one feet square.
The second charge, the same.
The third charge: try move the stick left and right, front and back, but not to move the chopper, but for you to watch the movement of the rotor, and which way the wind from the rotor blows.
The forth charge: run the rpm higher, but objective as in first charge.
The fifth charge: same as fourth.
The sixth charge: Try flying a few centimeters high above ground, but stay in the box.
The seven charge: same as the sixth.
The eight charge: you probably be competent enough to fly the chopper anywhere you want it.
I was wondering, how long a charge would last. If it is like a phone battery, for days, then this flight training must be very boring and down right stupid. So I started faithfully step one. Ade said the battery was fully charge the night before, so I could start the lesson rightaway. After ten minutes of trial, the rotor stopped, while the lights on the chopper were still flickering brightly. My son said the battery is flat. I wished it would last longer.
“Ten minutes?”
“Yes, dad. Otherwise you’ld play all day and forget everything else. No, actually it’s the battery technology that is still lagging behind. Time to charge, half an hour”.
Oh, so the lesson make sense. I made a target to fly on the fifth charge. But on the second charge I found the left and right control was reversed. I have to read the remote control manual to correct it.
Second charge went without incident.
Third charge will have to wait untill tomorrow.
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