Problems!! 14MZ 2.4 R6014FS

[03fomoco]

	Quote: Originally Posted by diamondave5
	you guys in florida heat not having problems?....maybe you need to be west of the mississippi

Don't forget they get 2500 more feet of atmosphere to protect them from radiant heat.

[Jurgen Heilig]

	Quote: Originally Posted by rcflyer
	Are these made of plastics or metal? How are they fastened to the fuse? Thx

They are metal and they are not ideal as air scoops. Use some nice NACA air intakes / outlets for electric flight - they work much better.

Jürgen

[rcdart]

	Quote: Originally Posted by rcflyer
	Are these made of plastics or metal? How are they fastened to the fuse? Thx

If you are talking about the exit guides, they are metal and stuck on with thick CA (Loctite 454)

[rcflyer]

	Quote: Originally Posted by Jurgen Heilig
	They are metal and they are not ideal as air scoops. Use some nice NACA air intakes / outlets for electric flight - they work much better. Jürgen

Jurgen, any links? Thx

[diamondave5]

	Quote: Originally Posted by 03fomoco
	Don't forget they get 2500 more feet of atmosphere to protect them from radiant heat.

didnt think about that, i know the sun feels hotter to me here than it did in pennslyvania, even when temps were high in summer there, it cooks me more here, i was around 300-400 feet asl back east

[Flyfalcons]

Diamond Dave, the heat in Florida typically doesn't reach that of the desert. It's just so darn humid that it feels more like 200 degrees.

I'd really like to hear some heat numbers from guys with planes that have fully enclosed fuselages. My Edge is fully enclosed and has no exposure to the sun but I don't have a temp gauge to stick in there. I'm willing to bet without the direct sunlight peeking in that the temps on the ground are much less extreme.

[Jurgen Heilig]

	Quote: Originally Posted by rcflyer
	Jurgen, any links? Thx

Just an example - Graupner stock number 2998:

http://www.cmc-versand.de/Graupner-L....html?ref=1002

Jürgen

[grayuk]

Guys.
We need to get this in context, the sky is NOT falling.
Lets look at what has been reported.
We have a handful of failures in Arizona and one or two others in very hot places.

All of the failures (as far as I can tell) are in large prop aerobatic models with large canopies and the rx’s in the canopy. Other flyers in hot areas such as Florida are flying jets with no issues reported (as far as I know).

Reported failure temps of the RX body is 167 F. 75C.

This is not ambient air temp but the temp the rx has got to by radiant heating through large transparent or semi transparent canopies. Basically the greenhouse effect has cooked the rx. I also wonder if the large curved canopies are acting in some way as a lens and concentrating the suns energy (magnifying glass and paper!)

We also know from work done by a German guy called Jurgen that the temperature rise on an rx from above ambient by its own heat generation is nominally 9F or 5C.
So whatever the ambient temp of the air is we get another 9 of 5 to add to it.

So if the failure temp is 167F/75C without any radiant heating or greenhouse effect the rx can take an ambient temp of 158F or 70C.
Now this is bloody hot! Where in the world does it get to those temps naturally? (And would you be out flying?)

Just looking at the 70C for a moment and put it into context , the highest ever recorded temp on earth was 56.7 °C (134.0 °F) Death Valley, California USA 10 July 1913.
(Ref: http://en.wikipedia.org/wiki/Extremes_on_Earth ) remember this is air temp and does not include greenhouse or concentrating effect behind plastic or glass covers.
For most of us in the world a very hot day is to 35C / 95 F if we go to extremes lets say 50C which is 122F we are still nowhere near the required ambient failure temp of 70C 158F. (The highest ever recorded temp in England / UK was 38.5C in 2003).

I did tests myself today on two models, Hawk and L39.
The Hawk has a canopy floor and the RX is about 3 inches below that.
Picture 1 shows the ambient temp today was 29C/84F
I placed the thermocouple on the rx body and recorded only a 1 degree rise in temp (without the rx on) to 30C/86F.
The L39 has an open canopy floor with the rx fitted to the side of the fuselage below what would be the canopy floor, so potentially it is worse than the Hawk.
Pic 2 shows the temp recorded at the rx 31C/87.8F. A rise of 2 C only (without the rx on). It can be seen that the lack of floor and the greenhouse effect has doubled the temp rise. (Very simplistic but you get the point).

So for those of us flying in temperatures up in the 50C/122F area, the first thing to do is remove as much of the radiant heat capture as possible.
Get the rx out of the canopy and under the canopy floor. Consider covering the canopy with a white cloth while standing in the sun.
I agree that some radiant energy will still be present in the cockpit and that in turn will warm the structure etc.etc. But it is not going to get the rx up to the kind of temperatures needed to fail.

We know from posts that Futaba are looking into this, but until they conclude, I see no reason why we should not all continue to fly, most without any changes and some of us with some minor alterations.
For the rest of us not living or flying in these extreme temps I propose that you just go and fly!
I did today, all 3 FASST models (2 Jets and 1 Prop), one with a 14 channel rx, one with and 8 and one with a 6. All performed perfectly as normal and I had a great day.

Paul

[reyn3545]

You're missing one key point... a 14 channel receiver should be designed for giant scale airplanes with greenhouse effect canopies! What else can you possibly put that many servos in?

[Judge]

	Quote: Originally Posted by reyn3545
	You're missing one key point... a 14 channel receiver should be designed for giant scale airplanes with greenhouse effect canopies! What else can you possibly put that many servos in?

A giant scale glider for one.

Ailerons x2
Spoilers x2
flaps x2
rudder
elevator
tow release
retracts
wheel brake

That's 11

Jets also use a bunch of channels.

But I agree, giant scale aerobatic planes are probably the most common application.

But again, until we know the actual root cause we cannot point fingers. It is all idle speculation right now.

It may turn out to be an unanticipated design flaw. It might be a bad batch of components. It might just be that they really did not take into account the end user environment. So while it is amusing to speculate, it will be even more interesting to know what is actually going on.

[grayuk]

	Quote: Originally Posted by reyn3545
	You're missing one key point... a 14 channel receiver should be designed for giant scale airplanes with greenhouse effect canopies! What else can you possibly put that many servos in?

No i think you are missing the point actually, I am not saying dont use it, all i am saying is, get it out of direct sunlight.
Jets also use a large amount of servos/channels that is why I brought it.

[Jurgen Heilig]

	Quote: Originally Posted by grayuk
	... Reported failure temps of the RX body is 167 F. 75C. ... Just looking at the 70C for a moment and put it into context , the highest ever recorded temp on earth was 56.7 °C (134.0 °F) Death Valley, California USA 10 July 1913. ...

Hi Paul,

you must have missed this part of the discussion:

http://www.flyinggiants.com/forums/452476-post383.html

and I can beat your temperature record (although not by much): 57,3°C on 13. Sept. 1922 in El Assisija (Africa).

Jürgen