Bell Bloke
04-07-2007, 06:51 AM
I know this is a bit long folks but I think you should read this one as it may save your turbine.
Well at last 'MIRO' is back and better than before, with its new home grown uprated main gearbox it can now handle all the power that that massivley punchy Wren can throw at it.
Those following the 'Miro Saga with know that after 80 perfect flying hours it went in due to a radio problem. This has now I'm happy to say been traced at last (I think) with the help of a radio boffin.
1. The radio going in and out of failsafe on the ground with nothing running was not the cause of the crash!! Huh? No, it was due to me putting the radio on the roof of the car with antenna in a little. This apparantly can reduce the transmission to zero and so induce a failsafe. Did you also know that you should never even stand near a large metal object when flying because, according to radio geek, it can rob you of all of your range.... Radio geek also said that large wet buildings, wet grass, & even wet trees can effect your range hugely. This will of course not bring you down but if it were coupled with a badly routed aerial or a noisey bearing, then you are in trouble, he says.
2. The cause of the crash was a noisy bearing, no not a main shaft or engine bearing but the very difficult to check, main pinion bearing. Infact what happened is the bearing was fine but the pinion was spinning in the bearing inner which over the roar of the engine we could not hear. This meant that ultimately the reciever couldn't hear the transmitter and so game over.
So after all that it would appear there were 2 seperate issues and on seeing the failsafe activate on the ground with nothing running we went of down the wrong track. Had we acted on the lockouts we saw in the air we would naturally assumed metal to metal and replaced every bearing on 'Miro' there and then.
Anyway back to Mr Radio Geek. He set about re-routing the antenna because he said that it ran too close to the side frames, and that this would reduce the range...and he was right.
He also said that a quick easy control test is to check your radio range out of the model and with 1 or 2 servos plugged in, this will give you a true range, then install it and re-test the aim being to get the same range as before.... 'We know all that I hear you old timers cry...well I bloody didn't 'cos I don't fly in a club, and there are so many people who say they know in clubs but don't.
Finally you plug in your various regulators and speed controllers etc and re-test, now how is your range?
How many of us just plug everything in and then range check, because that's what I've always done.
So now here is the crunch, the Fadec when plugged in did have an effect on the range even with a ferrite ring on. The Futaba radio got 78 yards with the aerial 1 segment out, but once the Fadec was plugged in this was reduced to 50 yards. Yes that's still fine, and I've always had that kind of range with the turbine in the past but, and here is the scary bit. If you postion the antenna too close to the side frames the range is as follows, with 1 transmitter segment out. 44 yards no Fadec and only 18 yards with the Fadec in, now that is starting to get a bit borderline. Yes it is true that for this test Miro was nose in and on the ground, this being the weakest signal presented because the aerial runs tailwards, and that in the air there may never be a problem. However what happens if you are standing too close to a car with these other factors in place...well I think you folks get the picture.
So look I'm sorry to waffle on here but as you know me by now I post as I find, I'm not an expert but I fly a hell of a lot and I always push the limits. A Turbine helicopter represents a considerable investment to some people... I'm just trying to protect your interest and mine.
So what of the Fadec? Well had I not done a check with/without, I would be none the wiser and happy, but I have and I am now wondering if anything can be done to improve the effect it has.
Any thoughts?
Regards as always, Bell Bloke
Ps. Get range checking folks, because all of these factors add up to reduce range and just because you have never had a problem don't think you are safe because PCM is all or NOTHING!! 'Miro' seconds before it went in, had not a glitch not a twitch, nothing, and then there was NOTHING....
Well at last 'MIRO' is back and better than before, with its new home grown uprated main gearbox it can now handle all the power that that massivley punchy Wren can throw at it.
Those following the 'Miro Saga with know that after 80 perfect flying hours it went in due to a radio problem. This has now I'm happy to say been traced at last (I think) with the help of a radio boffin.
1. The radio going in and out of failsafe on the ground with nothing running was not the cause of the crash!! Huh? No, it was due to me putting the radio on the roof of the car with antenna in a little. This apparantly can reduce the transmission to zero and so induce a failsafe. Did you also know that you should never even stand near a large metal object when flying because, according to radio geek, it can rob you of all of your range.... Radio geek also said that large wet buildings, wet grass, & even wet trees can effect your range hugely. This will of course not bring you down but if it were coupled with a badly routed aerial or a noisey bearing, then you are in trouble, he says.
2. The cause of the crash was a noisy bearing, no not a main shaft or engine bearing but the very difficult to check, main pinion bearing. Infact what happened is the bearing was fine but the pinion was spinning in the bearing inner which over the roar of the engine we could not hear. This meant that ultimately the reciever couldn't hear the transmitter and so game over.
So after all that it would appear there were 2 seperate issues and on seeing the failsafe activate on the ground with nothing running we went of down the wrong track. Had we acted on the lockouts we saw in the air we would naturally assumed metal to metal and replaced every bearing on 'Miro' there and then.
Anyway back to Mr Radio Geek. He set about re-routing the antenna because he said that it ran too close to the side frames, and that this would reduce the range...and he was right.
He also said that a quick easy control test is to check your radio range out of the model and with 1 or 2 servos plugged in, this will give you a true range, then install it and re-test the aim being to get the same range as before.... 'We know all that I hear you old timers cry...well I bloody didn't 'cos I don't fly in a club, and there are so many people who say they know in clubs but don't.
Finally you plug in your various regulators and speed controllers etc and re-test, now how is your range?
How many of us just plug everything in and then range check, because that's what I've always done.
So now here is the crunch, the Fadec when plugged in did have an effect on the range even with a ferrite ring on. The Futaba radio got 78 yards with the aerial 1 segment out, but once the Fadec was plugged in this was reduced to 50 yards. Yes that's still fine, and I've always had that kind of range with the turbine in the past but, and here is the scary bit. If you postion the antenna too close to the side frames the range is as follows, with 1 transmitter segment out. 44 yards no Fadec and only 18 yards with the Fadec in, now that is starting to get a bit borderline. Yes it is true that for this test Miro was nose in and on the ground, this being the weakest signal presented because the aerial runs tailwards, and that in the air there may never be a problem. However what happens if you are standing too close to a car with these other factors in place...well I think you folks get the picture.
So look I'm sorry to waffle on here but as you know me by now I post as I find, I'm not an expert but I fly a hell of a lot and I always push the limits. A Turbine helicopter represents a considerable investment to some people... I'm just trying to protect your interest and mine.
So what of the Fadec? Well had I not done a check with/without, I would be none the wiser and happy, but I have and I am now wondering if anything can be done to improve the effect it has.
Any thoughts?
Regards as always, Bell Bloke
Ps. Get range checking folks, because all of these factors add up to reduce range and just because you have never had a problem don't think you are safe because PCM is all or NOTHING!! 'Miro' seconds before it went in, had not a glitch not a twitch, nothing, and then there was NOTHING....