Problems!! 14MZ 2.4 R6014FS

[torquen]

I have not experienced the servo moving "thing". I just setup a 35% yak yesterday for a buddy of mine. 14mz 6014 receiver and all Futaba servos. When you turn on the switches the receiver instantly links up to the radio and goes straight to center. I turned on both of my 40% planes and they both go directly to center as well.
The people that are getting a servo movement, are you running Futaba servos? Because with 5 different receivers in 3 different planes I cant get this to happen.
Garrett Morrison

[grayuk]

Interesting feedback.
I have the same problem on a 14 rx with a 12FG.
Unfortunately it is the retract servo that does it and my gear goes up!
I have posted on the Futaba questions section but no answer from Bax or any other.
It always goes the same way so I will probably reverse the servo function so it always puts the gear down.
Paul

[grayuk]

	Quote: Originally Posted by DR10044
	By the way, the 6ex performed without a hitch last summer. I flew on many a 90 degree day.

I have flown the 6EX and now the 12FG, receivers used are 6,8 and 14 channel.
I have had ZERO problems with the gear; it has functioned perfectly in prop and jet alike. Temps in the UK are not as hot as we are seeing on this thread but, on the hottest days last year and the coldest days in the winter, I never had one issue.
The servo deflection is a pain, but not a real problem, and the temp issue that this thread is concerned with only kicks in at extremes forced by radiant heating.
I intend to monitor rx temps on the ground during the summer months and compare with ambient (just out of interest).
I was reading through an RCJI last night, the one with the boomer on the cover (Feb-March 08). There is an interesting comment in there by Dave Wiltshire in the ‘New to turbines’ section).
He is talking about the Spekrum system and states…”with the Spekrtum System the components used means that the maximum safe temperature is 85C”…. which is 185F (just 18F deg above Futaba) so it appears there is a documented lower limit on these as well. As is known, these temps cannot be reached with just normal ambient, but on very hot days, rx exposed to direct sunlight, both systems are vulnerable…
Along with the Futaba at 167F it makes you wonder how many mysterious crashes have been caused by this that have been attributed to other issues???
It looks to me that this is something that is inherent with the technology; maybe we just need to re-consider our installations. It is something we have had to do many times over as new technologies come along. Consider the learning curve associated with Turbines! Many crashes were the result of ‘conventional’ installs that were just not up to turbines demands. Big spark engines are another; more powerful digi servo's requiring higher powered systems and power boxs.......we had to change to move with the technology. This is true with the FASST lower voltage issue on servos, manufacturers of servos and add on powerboxs etc. are changing to match the technology change.
Those of us that are old enough will remember when the pulse width changed on rx outputs, (1.5ms to 1.2ms I think). It was a pain; our entire stock of old servo’s had the wrong centres.
I think we have to prepare ourselves for the fact that this may not be a ‘design issue’ of a ‘batch problem’ it may be the technology 'as it stands', we may have to live with it and adapt…

Paul

[d_wheel]

In my experience, the difference lies with the servos and not the receiver. The receiver does not output a pulse at all when turned on, but waits until it connects with the transmitter. I always get a movement with analog servos, both Futaba and other brands, but never see it with digitals of any brand. I have also experienced this with XPS and Spektrum/JR. With Futaba and XPS the servos will stay off center until the receiver and transmitter make connection. With Spektrum/JR, you might not notice it as much because the receiver starts sending the bound servo positions as soon as it boots up. If the servo moves quite a bit when first turned on, you will see it jump and then almost immediately go back to the bound position. With retracts it can be just enough movement to unlock the mechanism and let the aircraft fall.


To avoid this, use all digital servos.

Later;

D.W.

[grayuk]

I have never seen it with Futaba PCM, (analogue servo's) i believe this is becasue the rx does not output any movement of the servos untill it get a recognised signal (a bit like failsafe hold). I have seen it in earlier PPM system.
Paul

[bodywerks]

WOW! 45 pages?? I won't bother to read it unless most of the posts are actual accounts of problem/possible solutions and not namecalling/bashing...would I be wasting my time?

[03fomoco]

	Quote: Originally Posted by bodywerks
	WOW! 45 pages?? I won't bother to read it unless most of the posts are actual accounts of problem/possible solutions and not namecalling/bashing...would I be wasting my time?

Yes I mean no, ok yes.

Dave

[bgold]

The sun was shinning finally here in Oregon and temperatures soared to the high 70's and after all this I was very interested to see what temps were in my plane. When I first started putting my 35% Yak together the temp of the receiver case was 72F, by the time I got the wing tube in, both wings on and bolted down and the servos plugged in the temp of the black receiver case, exposed to direct sunlight, had increased to just over a 100F and the surrounding structure was still in the low 70's. My canopy has a floor but the receiver is mounted up high right underneath. I covered the canopy area with a large white towel when the plane was just setting arround. Flew several times with no problems. When I took the plane apart after about four hours the temp of the receiver case was 89.

Just messing around we took the temperature of the skin of the airplane while sitting out in the sun. Areas covered in white were 88 - 89, red was 94 - 96 and areas covered in black were 129-130F. Ambient was about 75F when we did this. Diamond Dave I think you have that Yellow and Black Yak and that black covering may be causing a lot of your heat issues inside the plane. I think protecting a receiver from direct sunlight and routine care during hot conditions (I know 75 isn't hot) will probably eliminate heat issues.

Bill

[Julez]

	Quote: Originally Posted by tobytorkn
	i have read a couple of times in this thread about why jr uses mutiple receivers for 2.4. why is it that futaba does not have to use multiple receivers placed in different configurations throughout an aircraft? i read about line of site, etc. what is the difference about futaba that excludes it from the same technique used by jr and now supposedly xps is going to multiple receivers as well? i would like a technical reason, not a guess. julez, any ideas? thanks, toby silhavy....

Fasst uses one reciever chip, two antennas and one switch, which switches one or the other antenna to the reciever.
Before a packet is sent, a preample is sent. In the middle of the preamble, the switch switches to the other antenna. After the preampble has been sent, the data recieved by the 2 antennas is compared, and the switch selects the antenna with the best reception. By this antenna, the data packet, which contains the control information, will be recieved.
So basically, the 2 antenna approach offers the same benefits of the 2 reciever approach, concerning diversity.
Both systems are able to recieve signals at 2 different locations, and both are able to determine which location is best for a given packet.

Cheers,

Julez

PS: Drop me a PM if you need the exact patent script.

[wingster]

As a possible fix, how about taping or gluing some white paper to the side of the receiver exposed to the sun.

[d_wheel]

I have been an electronics tech for many, MANY years and learned a long time ago that heat is an enemy of electronic circuitry. If I had an aircraft whose innards were reaching 160 degrees I would do something about it regardless of any problems it might or might not be causing. Not saying that Futaba shouldn't look into this, but it seems that some kind of venting or shading is definitely called for with anything reaching these temperature extremes. My electric powered 1/4 scalers have internal batteries that reach around 130 degrees at times. With proper air flow through the fuselage, this has never been a problem. Looks like you wet power guys need to pay attention to us electric heads and learn a few cooling techniques.

Later;

D.W.

[bodywerks]

I know there is probably a lot of useful info in here, and d_wheel, I am sure you are right that heat is the enemy of electronics. But the bottom line is that other manufacturers aren't having this problem, and as far as I know, Futaba receivers used to not have this problem. Now there is a problem, and it is unreasonable to ask the end user to make sure they properly ventilate their receivers to avoid thermal shutdown - period, plain and simple, end of conversation. Futaba needs to address this, and they need to start doing so YESTERDAY!.

[jonkoppisch]

Well, the good news is that maybe it's a pretty contained problem. There doesn't seem to be planes falling out of the air at Joe Nall (at least not because of the heat issue :^) It looks like there has only been a couple of lost planes there so far (ate by trees?)

[MartinT]

Can anyone at Joe Nall report on the termperatires at the event?

Also, maybe a poll of the FASST pilots who are successfully flying at this event to find out what they have done to assure their receivers are not over heating, if any?

I would like to see some positive information to help us +25 year Futaba pilots past this problem. I fly in Arizona so right now I am grounded to to be save and have done testing like many others with the exact same results. I am also looking at ways of avoiding this problem and will report any information obtained.

[cyco]

there wont be any problem if you dont burn your RX in the sun... keep it cold like puttying a towel over the canopy.

and if you have enough Air in and outtake in your fuselage nothing will happen.
i dont know why knobody made this "trouble" by 35MHZ 72MHZ and so on...
ic specs havent changed much


well, even in my Delro XXL Raven (3,1meters span) with open resos/pipes in the fuselage i dont have probs at the hottest temps with the 6014 Fasst. -correct airflow in the fuselage, sure.

regards, Chris