Ron101

My Feedback: (22)

Hey guys,
Im building a Yellow Twin F-18 and was going to start ordering my RX and servos. As many of you know the Yellow Twin F-18 has a good amount of carbon fiber in it for reinforcement (wings, fuse, stab, rudder)
I have been useing Futaba Fasst since it came out and have had zero issues with it... I was planning on running a 6014 RX.

Should I be concerned about the carbon fiber? I really don't want the antennas mounted on the outside of the plane, but will if it's must.

I could route one of them on the bottom of the plane, I could also have them pop up behind the cockpit deck under the canopy

any thought or personal experiance?

Thanks
Ron

schroedm

My Feedback: (1)

Ron,

I have 2 x 6014s in the nose of my 2.5m Futura. The fuse is over 9ft long and the rear 6ft is all carbon, contains thrust tube, 5L fuel and turbine.

After a few flights I am yet to see any switching between the 2 RXs (as per PB Royal screen) showing that the RF link was solid and remained so throughout the flight on the primary RX with no need for it to switch to the secondary.

Rgds,
Mark

basimpsn

My Feedback: (5)

Another question is, What is the Myth about carbon fiber? Is it (A) Resonance frequency close to 2.4 ? or does it act like a reflector. Was any test done on carbon fiber?,, For me I would worried more about flying in very moisture (Damp) condition base on the resonance frequency of water is 2.4

Just my opinion

ddlstang

My Feedback: (2)

As long as the antennas are not in direct contact with the carbon you should be fine. I have a rx lying directly on a carbon panel in a comp arf, just have the antennas elevated and one straight up.

Ron101

My Feedback: (22)

Thanks guys
I'll be sure to not let them touch the carbon
So it's sounds like I should be fine

paulsf86

My Feedback: (52)

You might contact Bill Baxter at Futaba support. I am sure he will give you a great amount of assistance.

Paul S

pfact

My Feedback: (92)

Futaba makes replacement antennae for use in carbon encased fuselages.

shop.rc-electronic.com/e-vendo.php?shop=k_emcotec_e&SessionId=&a=article&ProdNr=RF0959400&t=861&c=865&p=865

Their idea is to have the antennae protrude outside the plane.

That said, several of our planes have carbon almost completely surrounding our receivers, and we haven't noted any problems

Phil

sideshow

My Feedback: (11)

More importantly....when can I see it fly!

Ron101

My Feedback: (22)

going to be awhile Bob..lol
check the other site for my build thread....

whats up with this wind? man can't get out and fly it's been a mess... hope to see some nice days soon

later bud

sideshow

My Feedback: (11)

Don't know....this non-summer stuff is killing me. Lemme know if you need any "help"...more than glad to help a bro out...

c/f

My Feedback: (1)

If one does a search on 2.4G and carbon fuses you will find that the DLG hand launch gliders and other types of gliders are the last frontier for that technology to conquer. Those guys are pushing the c/f envelope to the max and a mixed batch of success..

ilsan

I almost lost my Ultra Lightning 14 days ago in a complete lock out situation.

The receiver was placed on its dedicated place at left side on mounting plate
with antennas placed with one pointing backwards and the other pointing straight up 90 degree from the other antenna.

The plane is pretty loaded with CF in nose section so I insured that the antennas
was as far away from the CF areas as possible, that didn’t help much .

The plane was a bit far out from me when it went in lock, but not that far away.
Luckily the plane went in FS with all control surfaces in neutral so the plane banked very slowly to left and toward the ground,
after a few seconds when bank angel was about 50 degree I started to gain control over the plane again and I got it home in one piece.

I have now replaced the receiver with a new one on a different location and placed the antennas different,
the receiver is elevated up from the mounting plate and one antenna is going down and out of the airframe pointing backwards and the other up in the canopy.

No problems so far, however I don’t dare to fly the plane too far away yet in fear for a new lock out situation,
it’s very frustrating to be a spectator to your own plane.

I believe receiver and antenna positions is very important in planes with much carbon.

Carsten Groen

ilsan,
do you by any chance have a picture of the antenna postition when you had the lockout ?
(my friend and I have a couple of UL's here that soon will go in the air, one with FASST and one with Weatronic)

smchale

My Feedback: (67)

What is Futaba's postion on this? I too am curious.

readyturn

My Feedback: (9)

That is a good question. I would like to know how Futaba feels about the replacement antenna that were mentioned. These are 400mm (15.75 in,) in lengeth so they could be placed
outside the fuselage.

Rick

smchale

My Feedback: (67)

Here's a start: http://www.futaba-rc.com/faq/faq-receivers-q1071.html

Receiver Technical Information
Can you give me detailed information on how to set up my 2.4GHz FASST receiver in a full carbon plane?
Carbon fiber fuselages are electrically conductive. This means that they can attenuate radio signals in the higher frequencies. For model aircraft, this means that the antennas must be exposed to the transmitted signals. In the case of carbon-fiber fuselages, the antennas should be outside of the fuselage where they can always "see" the transmitter. That's why the Futaba FASST receivers have two antennas, so that you can position them so that at least one of them is exposed to the transmitter at all times.

Ron101

My Feedback: (22)

Right on, thanks Bob

Ron101

My Feedback: (22)

I saw that also Sean,
but was hoping that others had flown with the antennas in the plane

I think the best I can do is have the antennas pop out in the cockpit... with the plane above or going away they would be blocked by the fuse

I could also use the extended antennas and route them under the fuse, but not in love with that idea


thanks for the input guys

Ron

RUFTER

Wikipedia/ Faraday cage:

A Faraday cage or Faraday shield is an enclosure formed by conducting material or by a mesh of such material. Such an enclosure blocks out external static electric fields. Faraday cages are named after the English scientist Michael Faraday, who invented them in 1836.[1]
A Faraday cage's operation depends on the fact that an external static electrical field will cause the electrical charges within the cage's conducting material to redistribute themselves so as to cancel the field's effects in the cage's interior. This phenomenon is used, for example, to protect electronic equipment from lightning strikes and other electrostatic discharges.
Faraday cages cannot block static and slowly varying magnetic fields, such as Earth's magnetic field (a compass will still work inside). To a large degree though, they also shield the interior from external electromagnetic radiation if the conductor is thick enough and any holes are significantly smaller than the radiation's wavelength. For example, certain computer forensic test procedures of electronic components or systems that require an environment devoid of electromagnetic interference may be conducted within a screen room. These screen rooms are essentially work areas that are completely enclosed by one or more layers of fine metal mesh or perforated sheet metal. The metal layers are grounded to dissipate any electric currents generated from the external electromagnetic fields and thus block a large amount of the electromagnetic interference. See also electromagnetic shielding.
The reception of external radio signals, a form of electromagnetic radiation, through an antenna within a cage can be greatly attenuated or even completely blocked by the cage itself.

Cheers, Bart.

DougV

I asked that question (about the longer antenna) a few years ago, here is response from Futaba:

Antenna
Hi Guys,

We have had these antenna available for a while now. They were originally intended for boat use, but people have been using them for aircraft with no problems.

You can order these directly through your local authorized Great Planes hobby store, or from our Futaba Support line at 217-398-8970 opt 2.

The part number and suggested retail price is:

HSP79766 ANT 400MM
HSP79469 T7C 2.4 TX antenna
HSP79493 2.4 Receiver antenna

Sincerely,
Krysta
Product Development & Support Specialist
Futaba Service Center USA
[email protected]

Hope that helps,
Doug.

readyturn

My Feedback: (9)

Doug,

Great info, just wish that I had it a few minutes ago, as I posted the question up to Bax in the Futaba Forum. See if he says the same as the antenna guys.

Rick

ilsan

Hi Carsten, Sorry I don't have any picture here, but I will try to post a picure tomorrow,

Been there done that with my UL, the 40 cm antennas reduce the range a lot, when I took range check it failed after 10 meters, I read somwhere that it may reduce range with up to 30-40%?
I know people that replace only one of the antennas, they said that they never had a problem with that solution, however they had planes with almost no carbon inside.

Ron101

My Feedback: (22)

that doesn't sound to good!

Looking at my fuse better, I think the best solution is to move the RX to the nose of the plane. This gets it away from everything and there is very little carbon up there.
I'm not going to make my nose removeable, but I can still make a small tray up there with the RX on it... I think that will be best.

What do you guys think, looking at my pics

rhklenke

My Feedback: (24)

On a high $, high effort plane like that, I'd seriously consider using a two receivers and a Powerbox RSS:

http://dreamworksrc.com/catalog/prod...roducts_id=603

Its an additional $400 into your plane, but I'd wager that's about 5% (or less) of your investment?

Bob

Edgar Perez

My Feedback: (13)

I like Futaba. I use their Tx. However, in a high end aircraft, I will recommend a Weatronic setup. You will get realtime feedback on signal quality and can evaluate the impact of carbon. No guessing, you will know exactly what is happening and if you should be concerned.
Of course, all sorts of redundancy and other alarms available also.