Helicopters

After the accident I figured there must be something wrong with the front engine, or something associated with it, I tried some things out and its just didn't move from any power, so we we took the whole helicopter to a big toy store nearby my place where we had seen a guy doing repairs on a RC helicopter before.

The guy working there didn't think it was the engine though, so I let him take apart the 4-in-1 controller part and we found that a small component that he claimed to be some kind of safety, might have been a lost in translation thing or just something he said so Jane would understand because it really was no such things as a safety but a power regulator, basically just a transistor. He would repair it with no charge though so it was all good.

They didn't have any of that component in the store though but he guided us to where would could probably find it, so Jane and I went out on further excursion, leaving the helicopter itself behind on the way past my place. We did find the place we were looking for but after looking around in the hundreds of stores there we found that the one that most likely had what we were looking for was already closed, so we gave up for then.

A few days later we were planning to go out there together in the morning, but I was feeling bad and too tired so Jane went alone, it was the right place but of course they didn't have any in so she had to order some, and of course she couldn't just order one so she had to order five, but it still only cost 25 yuan.

That day she gave me my Christmas gift too, a small helicopter, like the one dad bought last year, it is really fun and it is practically unbreakable, we will have competitions later between the big and the small.

Jane had the afternoon off on Christmas and the components had arrived so she went out to get them and drop them off in my mailbox, but until yesterday I didn't have time to take everything to the toy store again but I did some research of what it was more exactly; it's a capsule with only one transistor in it, using 3 pins for source, 1 pin for gate and 4 pins for drain, it should be quite powerful and not break very easily, still accidents happen.

I had kind of hoped that he would just do it when I came there, it was just a small 8-pin component after all and shouldn't take much more than a few minutes, I could actually have done it myself had I had the tools, I wish I did have the tools now, so I had to leave it with him overnight.

When I went back there today there was something wrong, so we called Jane and after some explanations this is what was wrong: the front engine still didn't spin even after the component was switched, and the back engine, that he for some reason also had switched the component for, was spinning full power when the battery was connected, so something was obviously wrong, I inquired a bit about it and soon I just guessed that he had messed up some of the solderings and short circuited something. I took it home anyway just a bit disappointed.

At home I started researching a bit, I took pictures of the solderings too see clearer with some high def zoom and I was looking for pictures to see how the components should be mounted, I suspected that he might have turned one or both of them around. I didn't have much time though but after my afternoon classes I went home and did some more research, I called that to see what he said and according to him it seemed very likely that the component that made the back engine spin uncontrollably might be on backwards, it was the one not working at all that I had suspected but at least it was partly right.

After some more tests; trying to switch the engines, which the repair guy had said was really dangerous (I couldn't really see how that made any sense since its just a two pin connection and the engines are exactly the same, just connected in opposite directions) and discovered that at least the component for the front engine was working as it should and that the front engine didn't work with either component, which kind of implies something wrong with the engine. That was confirmed when I tried to help the lower rotor (the one for the front engine) and felt that it was actually trying to move, quite forcefully even, but had something stopping it, I helped it along and soon it was spinning by itself, but not as fast as it should and something was smoking so I unplugged the battery.

So I called dad again and explained my new found discoveries and while I did I also found what had been smoking, the connection plug for the front engine was partly melted, indicating that there might have been a bit too high effect on that one. I tried to spin the lower rotor again and now it was clear that something in the engine was broken, it couldn't move at all in one direction and in the other there was a frequent clonking sound.

My conclusion is as follows: The engine broke in the accident, probably something inside it twisted when the rotor turned itself around the axle and stopped the engine from spinning as it should. This would probably short circuit the engine itself which led to a way too high effect for the transistor and it melted. The repair guy couldn't understand why the engine didn't work after he replaced the component, actually doing everything right so far, so he changed the other one too but mounting it backwards, he probably experimented a lot with how it should be mounted,not with the one he mounted wrong though, but finally gave up and handed it to me as it was, the component for the back engine mounted wrong and giving a constant full power and the component for the front engine mounted right but trying to feed an engine that didn't work.

Solution: Came from dad, saying, we take that one as spare parts and I send you money to buy a new one, make sure to buy the same one though, I'll buy one but I'll try to find a silver one.

I might add some photos later!