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servo leads "crash"

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servo leads "crash"

Old 12-29-2003, 03:38 PM
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ajm
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Default servo leads "crash"

hello i have just flown for the first and last time my 72"flair edge 540 .i was using pcm and have flown at this field many times before but as it left the ground there was no control at all ,after some fantastic flying it went in hard flat out and died .my question is that i had to use ext leads on 5 servos .cos of this was my first biggy i did not now any different but i have just heard these could have caused the eratic behavier ,does anyone agree cos i want another but dare not till have sorted the problem.cheers[][] ps did range check and that was ok?have tested said receiver and crystal in smaller plane no lead ext and all was ok ??help
Old 12-29-2003, 06:03 PM
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TerrellFlyer
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Default RE: servo leads "crash"

Did you do a range check before take off,did you tie the connectore together so they can't come loose,to me it sounds as a battery at the rx came loose or switch went bad.I fly some gaint size planes and I've never had a problem, a 72" plane shouldn't be any problem
Old 12-29-2003, 07:15 PM
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Stick Jammer
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Default RE: servo leads "crash"

I agree with TerrellFlyer. I doubt the servo extensions were the problem. Sounds like something made the PCM Rx go into lockout. Did you do a ground range check with the engine at full throttle? It appears that this is when the receiver locked out.
Old 12-30-2003, 03:20 PM
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Default RE: servo leads "crash"

ORIGINAL: ajm


.... ps did range check and that was ok?have tested said receiver and crystal in smaller plane no lead ext and all was ok ??help
Did you also use the same battery pack from the Edge? What capacity was the Edge battery pack? Was it new and fully charged?
Old 12-30-2003, 03:44 PM
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ajm
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Default RE: servo leads "crash"

hi thanks for the replies,the leads were all nice and secure,battery was used again as was the switch, in the smaller plane ,must admit to not range checking with engine flat out opps.am doing some tests tomorrow so will try every thing ,something has come to mind that the ailerons kept flicking to the right badley.weather permiting i will try loads to get it to go wrong before plane gets up.
battery 1100mah newish
futaba pcm new
crystal new
switch new
leads and servos new
poor plane r.i.p new
is this battery ok ? mmmmmmm await your verdict
Old 12-30-2003, 04:30 PM
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Default RE: servo leads "crash"

Re:The Edge

...was a metal clevis used to the throttle arm...ie, metal to metal?
...was the rx. aeriel routed externally on the model?
Old 12-30-2003, 04:56 PM
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ajm
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Default RE: servo leads "crash"

always use plastic clevis on 2 stokes eng was sc108 in edge ,but to be honest on my smaller 4strokes i have not noticed any prob erm 52 size in my super sports plane and the arial was outside down the lenght of the body
Old 12-30-2003, 04:57 PM
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Stick Jammer
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Default RE: servo leads "crash"

ajm,
Another thing I forgot to ask is if you had the the throttle channel failsafe set to idle? It sounds as though the plane left the ground at or near full throttle and stayed that way until it crashed. If the PCM Rx did indeed go into lockout, the throttle would have cut to idle.
Old 12-30-2003, 05:00 PM
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ajm
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Default RE: servo leads "crash"

the reason being that the planes i seem to pick which can take a 4 stoke engine never seem to have room to use a clevis ,plus why do manufacturers say use them ,in my latest greatplanes kit they supply a metal carb to snake fixing which i am using at the moment ,should i change this?
Old 12-30-2003, 05:04 PM
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ajm
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Default RE: servo leads "crash"

did have the failsafe on and yes thinking about it did go to idle and as it was heading to earth i had no control mmmmmmso that failsafe cut in quick then
Old 12-30-2003, 05:12 PM
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Stick Jammer
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Default RE: servo leads "crash"

Well, if it did cut to idle, then something definitely caused the receiver to lockout. If it was full throttle that caused the lockout, you should have been able to regain control as soon as it cut to idle but this doesn't appear to be the case.
Old 12-30-2003, 05:23 PM
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ajm
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Default RE: servo leads "crash"

trouble is it all happened so quick ,i now i am not the best pilot but i now when i do not have control ,i suppose it could have been sods law but i do not now ?it was quite high at one point which was when i thought it could be saved ,but like said i had nothing , thats why i have used the forum cos something is strange cos i now when i crash but this i can not get round in my little head .talking about it more it seems to point to battery and/or switch failier would you say cos that would cause failsafe to come in and cause lack of control ?what you think .sorry for rubbish english but not to sharp on keyboards ,thanks for replys
Old 12-30-2003, 05:48 PM
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Default RE: servo leads "crash"

I can tell you from experence that your extensions can cause that problem especially if you were using digital servos. I lost a plane due to the servo going into hold. After the crash, I use the 6 extensions that I had and 4 would fail 100% of the time, one would work 100% and the one I had on the plane was the only one that was intermittant.

I now don't use extensions (except aileron with gold contacts) and I make sure that all my connections are tight and taped to not come apart.
Old 12-30-2003, 05:52 PM
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Stick Jammer
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Default RE: servo leads "crash"

Well, now you've slightly changed what you think actually happened. If the plane was quite high at one point as you've stated, then it couldn't have cut to idle as soon as it left the ground (failsafe). If it was a switch or complete battery failure, then the receiver wouldn't have the ability to go into failsafe as that requires at least some voltage. If you had the throttle failsafe set and you are sure that at some point it did cut to idle, then chances are that it wasn't a switch or battery failure. There is of course a possibility that it never actually cut to idle, but it went deadstick for some reason. It's a complicated situation to figure out without knowing exactly what took place from the point when you lost all control to when the plane hit the ground. It does happen very quickly.
Old 12-30-2003, 05:52 PM
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ajm
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Default RE: servo leads "crash"

blast thought i had it .how do i test my leads.battery ,switch ,to prove they are ok or not?
Old 12-30-2003, 05:58 PM
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ajm
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Default RE: servo leads "crash"

yeah sorry did not think it could get this hard.trying to remember.took off ,went eratic,hit the deck, i am sure the engine was running ,but it was over very quick.oh well thanks everyone i will try to not let it happen again.my brain can not take it.ha ha
Old 12-30-2003, 06:00 PM
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Default RE: servo leads "crash"

Geistware,
I agree that a bad extension is a possibility, but the likelihood of all of his extensions going bad at the same time is very remote. He stated that he lost all control.
Old 12-30-2003, 06:06 PM
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ajm
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Default RE: servo leads "crash"

hello mr stick jammer thank you for sticking by me .i definatley had no control.took off ok then it went silly and i lost the lot no ele .nothing.trouble is i fly and learn alone so need your help .i am in a club but only get to fly 1 or 2 times every 3 to 4 months at odd times.and hardley see a sole.and i was on my own when this happened
Old 12-30-2003, 06:29 PM
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Default RE: servo leads "crash"

True, I was thinking he said he lost elevator control not all control.
You are correct.


ORIGINAL: Stick Jammer

Geistware,
I agree that a bad extension is a possibility, but the likelihood of all of his extensions going bad at the same time is very remote. He stated that he lost all control.
Old 12-30-2003, 11:07 PM
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Stick Jammer
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Default RE: servo leads "crash"

ajm,
One thing you've mentioned a couple of times is that the plane went erratic as soon as it left the ground. This is not typical behavior of a PCM receiver. If anything caused the Rx to go into lockout, it would either hold the last positions of all control surfaces or failsafe them to the settings you previously programed. Likewise if it was a battery or switch failure it would hold the last heading, not be erratic. You mentioned in your last post that you only get to fly 1 or 2 times every 3 to 4 months and you are usually learning alone. That's not a lot of stick time by any means. I'm not questioning your flying abilities but an Edge 540 72" WS can be handful on the maiden flight unless you have plenty of experience. Please forgive me if I'm wrong but it sounds as though there's a chance that you might not. This type of aircraft can get away from you very quickly, especially if it's out of trim. It's very easy to over control it when things start to go wrong. These things can happen so quickly that sometimes you don't even realize what your thumbs are doing and then it's over. Again, I don't mean to judge your skills, but your description of erratic and silly flight just doesn't fit in with normal PCM behavior.
Old 12-31-2003, 05:06 PM
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ajm
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Default RE: servo leads "crash"

well went flying today with all the same gear except plane and engine ,brill could of stayed for ever ,may of been me but i suppose i will never now ,right must get me self something bigger ,cheers see ya around ady

HAPPY NEW YEAR
Old 12-31-2003, 05:26 PM
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Default RE: servo leads "crash"

Another thing to check out is that some Futaba units also have low battery failsafe. Check to see what it is set for, because Futaba had sent some systems out with the factory default set to full throttle.
Old 12-17-2004, 10:04 AM
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Default RE: servo leads "crash"

Bit of a late reply to this thread I know, but I thought it would be worth mentioning. I 'had' a 65" Flair cap 232, which had two elevator servos running on a Y lead with one 'in line' reverser on one side. Anyway...first flight flying straight and true, the next second a vicious snap roll and a large pile of bits. I thought at first that this was redio interference and put it down to experience..However whilst I was putting the same radio gear in another plane after checking and double checking the leads, batteries, receiver etc, I was tightening the elevator horn screw on the servo and all of a sudden both elvator servo's went full movement in opposite directions!!! I then discovered that a light load on the servo with the inline reverser in it caused this to happen, not all the time but intermittantly.

Anyway I removed the inline (futaba) reverser and all is well, and now this radio gear works perfectly. BE AWARE!!!

My solution to this is now to mix channels 2 and 5 on my FF9. Reversers are BAD news!!!!

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