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Norfolk, England
Joined Sep 2001
6,587 Posts
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I hope you guys will bear with me, I'm no heli expert, and am having to work from memory, but have flown the Syma Apache, 3 channel heli. I'll just attempt to clear up a few points raised by the out and out novices here.
Coaxial helis, no matter if 3 or 4 channel, have very little wind penetration - if any at all. It's simply the nature of the beast that most don't fly forwards very fast. I've flown two brands of 3 channel Apache, and one 4 channel one (as well as various other 4 channel coaxials) and all have been much the same.
As regards quality, you get what you pay for. It's pointless to even try to compare a £35 Syma heli with a £85 E-Flite one. As for the chap who thinks Walkera helicopters are good quality, I think he may be disappointed. I've found them to mostly be very poor quality and very poorly set up. Expect to have to adjust things.
In general terms, for what it costs, the Syma Apache is a nice heli. I bought mine two years ago and learned a lot with it. It flew well, within the limitations of the type, looked good and trimmed out very well. I flew it for a couple of months, before moving onto 4 channel helis, and then sold it to a guy who still flies it. It has lasted well and nothing other than blades has needed to be replaced.
Part of the problem is that there are a lot of identical helis around, some even labelled as being Syma, that are actually cheap rip-off versions. Some of these are downright awful. I tried one and the transmitter switch stopped working after about three times. However, they may well prove a good source of spares. Buy a cheap copy and strip off it what you need.
When it comes to trimming these helis, IIRC, there is a rotating knob that controls rotation and sliding trims, one on each channel, that fine tune throttle and adjust forward and backward trim.
The knob should be turned against the direction of rotation until the heli remains reasonably still in the air. It may well be that it won't entirely cancel rotation, but it does get it to a reasonable amount, that can be supplemented with stick control. It will need to be adjusted as the battery runs down and the motor speed changes.
Throttle trim is best used to ensure the main rotors don't turn until the throttle is opened, and then for fine tuning to help maintain the same hover height.
Forward and backward trim is used to adjust, funnily enough, forward and backward movement without use of the stick. It should be set so that, with the stick central, the tail rotor is still. Then it should be moved in the reverse direction of any drift - if the heli drifts forward, move the trim back towards you.
Whilst on the subject of trim, a brief mention of the four channel version might be in order. That uses a slide trim, not a knob, for rotation (yaw) control. On the two I've flown IT IS REVERSED. So, if the heli rotates left, the trim needs to be moved left too, not to the right as would be normal. I also found that yaw control was in the same place as on a 3 channel heli, on the right stck. Normally it would be on the left with bank control on the right.
I mentioned this because mention has been made of 4 in 1 units and gyros. Only the four channel ones have these. The flybar does the stabilising on 3 channel coaxials. Many only have one link between blades and flybar, some have two but will work just as well with only one. The good part being that they tend to have ball joints on both sides so, if you break one off, use the other set.
When flying helis, keep stick movements absolutely minimal. Get the heli to around 4 feet up reasonably quickly, to get it clear of ground effect (the rotor wash bouncing back up and upsetting the heli) and then trim it for rotation until you have a fairly stable hover. Being close to walls and funiture will also reflect the wash and upset the heli. You may need to adjust forward/backward trim too, but expect the heli to take off either forwards or backwards, and be ready to cancel that with the stick.
The thing with flying them is that you need to watch them ALL the time. Note what they are doing and GENTLY correct it. Keep watching the heli and gently 'feel' it around the sky, using small stick inputs. Don't expect to just open the throttle and have a perfectly flying heli, it's very unlikely to happen - especially with cheap, 3 channel jobs. YOU need to fly them and that means starting out with plenty of clear space until you get the hang of it. An indoor area is best for the helis we are talking about. It's hard to get the trim right if there are outside influences, like breeze.
For meaningful results, 3 channel helis should only be flown outdoors in absolutely still air. Coaxials don't penetrate very well, but 3 channel coaxials don't usually penetrate at all - even a light breeze.
Sorry if this went on a bit, I was just trying to cover as many points as possible, as clearly as I could manage. I don't doubt you'll get differing opinions, but that's my advice, based on personal experience.
Great flying coaxial helicopters are out there, both 3 and 4 channel. I rather liked my Syma Apache and their little Chinook is brilliant, but I absolutely love my Twister Hawk and any E-Sky heli I've flown. Disliked virtually every Walkera type I've tried, for various reasons. I used to manage a model shop, so had the oportunity to try lots, without having to actually buy them - my excuse was that I needed to be able to advise the customers.
Pete
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