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Metal cote and Futaba 2.4 rx

Started by Tally Ho, January 17, 2011, 18:35:11 pm

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Tally Ho

I am in need of some advice with regards to metal cote covering and 2.4g. :co

Over the winter I have built a 1/5 Ziroli P47 Thunderbolt  which is now ready to finish up. I have my heart set on a   ali covering but I am not sure if there will be issues with reception due to the metal covering. I have just purchased a 12fg and 14 channel receiver which will be used on this aircraft. I m aware its advisable to have external areas which are an add on to the receiver, this is not as problem.  Has anybody had experiance with this method?

Last June, I ordered Flite Metal from the States, and its still not arrived,   :banghead: :banghead:

I have read most of the jargon on other forums relating to flight metal, aero foil ect . I didnt realise the same type of material was available through M Reeves models. Has anybody used this material, and if so, have any problems arised,




Phil_G

January 17, 2011, 18:53:18 pm #1 Last Edit: January 17, 2011, 18:54:47 pm by Phil_G
Just an opinion as I have no experience with metal coverings... but quite a bit with microwave RF.
This is one time I'd choose 35mhzover 2.4g, from an RF point of view what you have there is a large all-metal model.  I cant see a way of ensuring that at least one of the two aerials will always be line-of-sight to the transmitter when the airframe has no transparency at all to RF.  Surely in some attitudes  its bound to shadow both aerials, regardless of where you locate them. How could it not?    Sorry I know its not what you wanted to hear... but 2.4g in a metal airframe is a scary thought! 
Are there any alternative metalic-looking films that are RF transparent?
JMHO of course
Cheers
Phil

Yoyo

Quote from: Phil_G on January 17, 2011, 18:53:18 pm
I cant see a way of ensuring that at least one of the two aerials will always be line-of-sight to the transmitter when the airframe has no transparency at all to RF.  Surely in some attitudes  its bound to shadow both aerials, regardless of where you locate them. How could it not?


The only way I know of to make that work safely is to add one or more satellite receivers - effectively extra aerials that can be placed well away from the rx.

I'm not sure what's compatible with your radio gear but if you're going for a 12FG and 14 channel Rx I suspect the added cost won't put you off too much...

Doing what you like is Freedom
Liking what you do is Happiness

danishpasty

Can't help on the RX side I'm afraid but I have used the MR metal foil. Sticks like you know what to a hairy blanket. Tricky to aply. Does not seem to have the stretch which flite metal claims to have (though I have not used FM) so is not easy to work around compound curves and is very easily marked/dented thogh to be fair I am somewhat of a clusterf#ck.
Cheers, Rob

Tally Ho

Thanks for the comments fellows, much appreciated, :af

I still fly 35mg pcm as well as 2.4 so the gear is not a problem.  I agree with all that you say  on the 2.4  : : :P

As i said, I have already purchased the new 2.4 gear and Futaba do an optional set of antennas to extend the exsisting rx aerials to the outside of the airframe. Maybe I need to talk to Futaba.

Quote from: danishpasty on January 17, 2011, 20:00:41 pm
Can't help on the RX side I'm afraid but I have used the MR metal foil. Sticks like you know what to a hairy blanket. Tricky to aply. Does not seem to have the stretch which flite metal claims to have (though I have not used FM) so is not easy to work around compound curves and is very easily marked/dented thogh to be fair I am somewhat of a clusterf#ck.
Cheers, Rob


Thanks Rob, I have trialed the MR foil and found it to be workable with patience.  :'' You are right in the fact that it easily marks/dents, but it can be made to look superb with a few various finishing methods.




regards,

Frank


Yoyo

Quote from: frankfearn on January 17, 2011, 20:06:01 pm
As i said, I have already purchased the new 2.4 gear and Futaba do an optional set of antennas to extend the exsisting rx aerials to the outside of the airframe. Maybe I need to talk to Futaba.


The ideas of the satellite receiver(s) is not that they are extended aerials, but that they are extra aerials. You definitely would need yours outside the metal covering to work at all, but even then there will be a lot of angles where those two are both shielded from your tx aerial by bits of plane.

With a satellite receivers or two fitted carefully, you can arrange it such that at least one aerial has a clear view whatever you do with the plane.

A big dangly 35MHz aerial well outside the plane may work best for this one, but I've always been on 2.4 so I'm no expert on how that reacts to metal films...
Doing what you like is Freedom
Liking what you do is Happiness

Phil_G

Does the 14ch rx have the option of satellites?  If so Yoyo has the right approach. But Futaba have always ridiculed Spekky's use of satellite receivers - have they changed their stance :D ?

Cheers
Phil

HarryC

January 18, 2011, 11:37:00 am #7 Last Edit: January 18, 2011, 11:47:46 am by Mpx
On Flite-metal's website they give details of a range test they claim shows that 2.4ghz works fine with flite-metal.  But then they would say that wouldn't they?!

I use 2.4Ghz on large jet models that are coated in aluminium paint - and I mean real metal, not just humbrol aluminium colour!  BVM's metal-kote is aluminium dust.  This really tests 2.4Ghz as the models are large with plenty area to block a tiny aerial, metal coated, have lots of wiring and big batteries and carbon fibre and big metal engines, and I fly these largeish models out to dot in the sky distances.  I always get the aerials outside the model or at least outside the metallic part, if there is a plain painted part or a pitot tube it can be hidden in then fine.  During range testing I found that c/f is a bigger problem than metal coating.  I put one aerial out of the top of the model, and one either underneath or at the nose as low down as possible.

One reason I decided to get the Weatronic 2.4Ghz system is that it logs, second by second, the relative signal strength on each aerial and the number of frames received on each aerial, so I can really be sure how well a system is working and not simply have something that seems to work but is actually on the edge of losing it.  I check it after every range test and at the end of the day when I get home I review every flight on the PC.  What it shows is that 2.4Ghz is affected by metal coating.  For most of the flight what happens is that both aerials lose the odd frame or two or three per second, but that is out of 100 frames/second on each aerial and there is redundancy in that since the source tx is only making 40 frames/second anyway so each source frame is sent at least twice, sometimes 3 times in the transmitted 100frames/second.  If the rx failed to get every 2nd transmitted frame it would still get every original source frame from the tx.  (And the Wea system doubles up by having 2 tx aerials each sending 100 frames/second and 2 separate Rx each with one aerial in the Rx box so I can actually afford to lose 4 in 5 transmitted frames and still the rx will get all the original Tx frames!)  Therefore losing a few frames every second is not a problem unless two things occur - a long enough period of frames being lost continuously, and that to happen to both aerials/rx at the same time.  That has never happened.  Sometimes one aerial has a dreadful loss of data, down to almost zero frames in the second (though usually the signal strength is ok, indicating that corruption perhaps due to reflections, multi-pathing etc rather than simple blocking is to blame) but whenever that has happened the other aerial is working at top form.  Whenever an aerial has dropped to dangerously low levels of frames, it has never lasted beyond one second and the other aerial has covered it.

Therefore I believe that 2.4ghz can work with metal coatings as long as you do the work to get the aerials outside the model, on opposite sides, (above and below or left and right), as far apart as possible e.g. fore and aft, and follow the rules about pointing them in different directions.  Then do a thorough range test with the model being swung around the 4 main aspects so that you test it at a variety of angles, and so on

I would be more worried about damaging the flite-metal than radio reception!  Are you aware that flite-metal is very soft and every touch of your finger nail, putting it in and of the car, storage etc is going to dent it?  Klass kote UK sells flite-metal, I don't know if the MR stuff is the same or not.

brand1068

Quote from: Phil_G on January 17, 2011, 22:03:47 pm
Does the 14ch rx have the option of satellites?  If so Yoyo has the right approach. But Futaba have always ridiculed Spekky's use of satellite receivers - have they changed their stance :D ?


Nope - not as far as i'm aware - they still maintain they dont need it  :af

The extended antenna they offer though - you should be able to get both outside the fuz if its a concern.

Cheers,

~Chris
Sign up for the Winterton Model Show http://www.rcmf.co.uk/4um/index.php/board,288.0.html
Or See the site for details http://www.wintertonmodelshow.co.uk

Tally Ho

January 18, 2011, 16:48:41 pm #9 Last Edit: January 18, 2011, 16:50:18 pm by frankfearn
Futaba do not give you the option of satelite receivers. You can buy Futaba extensions to fit the standard 2.4g tx aerials which then are placed outside the airframe. 

Thanks to you all for your comments  :af :af

I have emailed Futaba and asked the question, it will be interesting to see the reply.

^-^

Phil_G

Two Frsky TFR8S FASST receivers can be cascaded to give 14 channels and 4-antenna, twin-rx diversity...  just a thought
http://www.frsky-rc.com/ShowProducts.asp?id=51
Phil



Yoyo

Quote from: Phil_G on January 18, 2011, 17:59:44 pm
Two Frsky TFR8S FASST receivers can be cascaded to give 14 channels and 4-antenna, twin-rx diversity...  just a thought
http://www.frsky-rc.com/ShowProducts.asp?id=51
Phil


I think they remain two separate receivers in that case, it's just that rx2 has it's channels shifted so it responds to tx channels 9-14 instead of 1-8.

They don't share the received signal (aren't connected together at all, in fact) so unless you are using them to drive parallel servos on the same surfaces you won't get any extra diversity. If one does lose its signal you'll only lose half of your servos though - which might be a good or bad thing!
Doing what you like is Freedom
Liking what you do is Happiness

Phil_G

Exactly right Yoyo - they're not connected, dont even need to share a battery. But on this type of model dont you normally split surfaces with two servos, one on each rx?  I dont know, I dont possess anything big or expensive :D just suggesting it as another option...
Cheers
Phil


Yoyo

Quote from: Phil_G on January 18, 2011, 19:56:22 pm
Exactly right Yoyo - they're not connected, dont even need to share a battery. But on this type of model dont you normally split surfaces with two servos, one on each rx?  I dont know, I dont possess anything big or expensive :D just suggesting it as another option...
Cheers
Phil



I don't possess anything big or expensive either... including planes!

I suppose it depends on whether you have a 14ch rx for 14 channels - retracts, bomb drops, err.. pilot moves?, umm.. smoke on?

Way out of my league, I've just got my first six servo glider and that's complex enough for now...
Doing what you like is Freedom
Liking what you do is Happiness

grayuk

There are many accounts of the use of FASST with metal coated fuselages.
None of them are negative, as you say, Metalcoat themselves report their results.
My own trials with FASST found it to be a very robust link with metal around.
I have done extensive trials including the rx inside a metal case, through thick stone walls, metal vans etc.etc. and it still works!
My advice would be to test it for yourself on the ground to build up your own confidence.

Paul

Tally Ho

January 19, 2011, 16:28:53 pm #15 Last Edit: January 19, 2011, 16:45:05 pm by frankfearn
I think that may be the best idea Paul, give it a go and build confidence. Im half tempted to fit twin 2.4tx, one top and one bottom, port, starboard?? 

Heres what Mr Futaba says,

"Make sure the receiver antennas can "see" the transmitter antenna. Metal and carbon fuselage construction can block 2.4 GHz signals. That means the antennas should be brought to the exterior of the model. "

_____________________________

"Bill Baxter, Manager Hobby Services/Futaba Service/North America
3002 N. Apollo Dr. Ste. 1 Champaign, IL 61822 USA


Read more: http://www.rcuniverse.com/forum/m_10270036/anchors_10273922/mpage_1/key_/anchor/tm.htm#10273922#ixzz1BV0UPeC5

HarryC

frank, I have been in touch with some people who have a lot of experience with flite-metal because my next project is another metal jet and I would like to try something different to BVM metal-kote.  Their advice is that flite metal is an exceptional product but for exceptional models that will have custom made protective bags and be handled ever so carefully, it simply doesn't withstand every day handling.  I think you will be better off with one of the specialist aluminium paints with a clear coat over it.

Tally Ho

January 19, 2011, 18:53:20 pm #17 Last Edit: January 19, 2011, 19:35:35 pm by frankfearn
You may well be right,  :af  , shame cause Flite metal was the way I wanted to go ???

Hows the BVM  Metal Cote,  Is there any interference problems with it??

Thanks


HarryC

Quote from: frankfearn on January 19, 2011, 18:53:20 pm
You may well be right,  :af  , shame cause Flite metal was the way I wanted to go ???

Hows the BVM  Metal Cote,  Is there any interference problems with it??

Thanks


If flite metal is what you want, and it is the best, then do go ahead, I just wanted you to be aware of its limitations before you go ahead!
I have not had any problems with BVM metal-kote using the rules I posted further up, but you will be lucky to get hold of it now, the airlines won't let it on their planes any more so BV can't post it, friendly airline pilots can't even take it on board with them to bring back.
I now use Sikkens Argentum.  Whatever you use, the realistic finishes require a heck of a lot of work and getting it just right, otherwise you get a humbrol paint finish.  They are not easy.  Solartrim chrome, flatted down with scotchbrite might make a reasonable alternative, I have an F-104 covered with it and it does jolly well.

Flite-Metal

September 24, 2015, 00:50:32 am #19 Last Edit: September 24, 2015, 01:00:27 am by Flite-Metal
I occassionally surf the net answering questions left unanswered. Typically one of our customers wiil answer but in this case, they did not.

First of all, I have a tremendous customer base in Europe, especially in the UK. Most customers are competing in
either FAI or in another scale focused portion of the hobby, as in jets and attend the WJM. I provide my potential
customers a high level of support with show & tell, and video examples of the specific feature questioned.

If there are any questions they can be directed to any of our UK customers who will always take time to answer as
they themselves asked way back when... ;^) Or contact us direct at ed@Traffic.net.co .


Dave Lowe

I covered from the wing trailing edge forward of my Hannibal in flight metal the rest of the aircraft in solartex I've been flying it now for 6 months using Futaba 14 SG transmitter and a F.sky reciever mounted inside the main body of the aircraft with both aerials inside one taped to the side facing forward the other facing downward and have had no interference of any sort.  don't know weather this will help or confuse.   $%&
Take off optional --- landing essential..

colin.breach

Just been reading through the items about aerial screening, 2.4 ghz, I had been concerned as the Barracuda I am building has a lot of metal framing on the cockpit , but think this will not be a problem..How does the 2.4g aerial extension work,obviously not just a matter of extending the short 2.4 stub,do you replace these with a screened cable with a short stub on the end.? Colin...