Thanks Subbu, but there is not much point in doing it on a completely different brand/setup.  Except of course, it will help us realize what will happen with Airtronics.

BTW, since we are having so much fun in this thread, it is time to open another one !  Let us have even more fun over there :

http://www.rcindia.org/chatter-zone/rc-crash-investigations-what-to-look-for/

 

Man!.. this is nice.. I have not given a single useful information in this thread, yet, I am one important guy to spill the beans!!...

Guess, No flying (the real thing) has its effects on me!

hye guys first set of test finished.
results as expected

set failsafe to 20%
and a bit of up elevator

gave it as much interference as i could with 2.4 ghz systems many mhz systems and mobile phones and you name it

then put the radio in range check mode even less signal power

handed over the radio to my sister in the other room about 15m away fail safe kicked in and everything worked as expected now will try it out in a bit of heat out in the sun now the temp was 30-32c and no signs of heating anywhere

in my opinion the two suspects can either be rx or the bec

also was checking out the failsafe of the new radio so no real bigtest done next will try simulating bec failure and then heat test

hey guys one more thing out of context but i got the second prize in English debate competition in my school

i know anwar bhaiya that performing these test on airtronics would not help but we can help in reducing further crashes on airtronics and if some common failure or cause arises it can be looked upon

Hey Folks let us sum up... Atleast I owe it to the readers of this blog to summarise

Cautions to be taken while using FASST rx from Futaba:

a. Clear air flow over the large surface areas of the rx. The rx standing on its shorter narrow edge to provide for large exposed surface area. Did Chan follow this ?
b. Provision for forced air-flow by way of a separate fan in case of large glow-planes and channelled air flow from the prop in case of electrics
c. Rx kept in canopies should be protected from direct sunlight when on the ground
d. Reduce possibilities of high current draw from the rx by the servos. Could be by making the servos reach end of travel in either direction before the actuation reaches its end of travel, thus limiting the current draw by the servo. If this is not possible, connect only the signal line to the rx, the power lines to be drawn directly from the BEC.
e. All other precautions as per Futaba instructions.


Now, when is our friend's daughter marrying the handsome 'beau' ? I may attend it if there is a proper invite!! He has fought really hard to save the damsel's face!!

And Ismail, my friend, you should read the poem "on His Blindness " by Shelley


Saju

Hey Guys ,
Apart from all the arguments and counter arguments I guess this thread should have been most educative for all as  each side trying to prove their theory has got out some fantastic resources that in terms of articles that can be referred to any time .
It has definitely achieved its purpose from the point of view of the aero modeler in being better informed about the pros and cons of 2.4 g .
The BIG PLUS is all now know the precautions to take when using 2.4 G receivers especially Futaba.

As for Chan who got this started in the first place the silver lining is he now knows at the cost of the funstar ( which he was about to retire in any case ) that  he needs to take added precautions with respect to cooling of the receiver in his 50 cc costly gasser .

So all of us have benefited immensely due to this thread and discussion .

A big round of applause to ANWAR and SAJU  for having provided us so much info. on 2.4G in general and FASST in particular  

Sai

PS Chan you owe us a big treat for having analysed your crash in such a way as to save you big time on the BIG BUDGET $$$$ YAK . I might be willing to settle for a Sunday lunch after flying  at an ECR resort with something cooooool to beat the heat ( you know what B__R)

hey sai uncle you forgot your name in the list saju uncle you and anwar bhaiya a loud applause to you
and for the 50 cc gasser chan bhaiya it would be good to make a nice intake and an exhaust as a precaution though i know you will but i will still keep on investigating this matter.




subbu

Quote from: mpsaju on July 22, 2009, 05:18:05 PM
And Ismail, my friend, you should read the poem "on His Blindness " by Shelley

Oh yes!... I feel like Ozymandias...  No worries... Soon I would be resurrected.

A BIG THANKS TO ALL OF YOU WHO CONTRIBUTED!! And the treat is definitely on!! This was a really really informative thread and this has become the black box of my crash!!

Quote
Clear air flow over the large surface areas of the rx. The rx standing on its shorter narrow edge to provide for large exposed surface area. Did Chan follow this ?

nope !! Not enough space inside the narrom fuselage!! But had made a hole below the RX mounting area hence solving the problem!!

For the 50cc, I would not use an external cooling system but would make use of the prop wash to have better cooling.. Would engineer a neat passage for the air to pass in through the cowl and out of the fuse after passing over the electronics!!  And this would have the new high speed 8 channel Rx!

- Chan

Chan, did the receiver have power after the crash ?  Did you notice the color of the LED on it (green or red) ?

You mentioned the BEC was badly hit, so this may be a mute point, just curious.

I had to pick up the Lipo, the BEC and the remaining bits of the fuse with the Rx in 3 different places !! So no chance of checking Rx binding at the crash site!!

- Chan

Thank you Chan.  That would have been interesting to know.

Let me point out another aspect of Futaba heat issue here.  If the receiver shuts down due to heat issues, then the light would turn from green to red.  But you do NOT have to rebind the receiver by pressing the little button, the light should turn back to green and the receiver should work normally when the temperatures comes down.  So the binding is not really lost, as it happens in the Spektrum world (rarely, due to various issues, not heat though!), rather it is just a shutdown of the signal reception function of the receiver with failsafe activated during that interval.

Quote from: chanvivek on July 22, 2009, 07:30:02 PM
A BIG THANKS TO ALL OF YOU WHO CONTRIBUTED!! And the treat is definitely on!! This was a really really informative thread and this has become the black box of my crash!!

Quote
Clear air flow over the large surface areas of the rx. The rx standing on its shorter narrow edge to provide for large exposed surface area. Did Chan follow this ?

I would not use an external cooling system but would make use of the prop wash to have better cooling.. Would engineer a neat passage for the air to pass in through the cowl and out of the fuse after passing over the electronics!!  And this would have the new high speed 8 channel Rx!

- Chan

Hey Chan ,
If I were you I would use a Rs 15/- PC fan rather than complicating life with redesigning the the fuse to  ensure hot exhaust air and residual lube air is not sucked in.
sai

Anwar ,
This thread and the prop thread could also be moved to the RC general section:
http://www.rcindia.org/electric-power/propeller-what-do-we-understand/

http://www.rcindia.org/radios-and-receivers/interesting-article-on-2-4-g-and-the-diff-between-dsss-and-fhss/


sai

Thats news to me!! Never came across this bit of info!! But unluckily I was not able to verify that !!

- Chan

I was just planning on making the plane as light as possible.  So using a PC fan would mean using an additional power source as I would not use the Rx power supply.  Instead, I can just make a vent (a series of gill like slits) for air to exit near the Rx.  That would ensure the air supply coming inside the fuse through the huge cowl would exit throught the vent hence cooling the Rx in the process!!  But I would also give the fan idea a go through!!

The only reason why I am getting paranoid about the weight is that, I would be reinforcing the firewall and also the fuselage and even that would add up weight!! The stock hardware is also pretty heavy and I just dont want it to end up like a sport plane!! Am planning to build a gasser that flies like a foamy !!

- Chan

Quote from: rcforall on July 23, 2009, 07:16:30 AM
Anwar ,
This thread and the prop thread could also be moved to the RC general section:
sai

Moved the prop one.  Since the rest mentioned are radio related, it seemed better to leave them where they are.

See additional information here :

http://www.rcindia.org/radios-and-receivers/are-you-still-skeptical-about-2-4ghz-radio-systems/msg10437/#msg10437

Another interesting post on how one needs to be pretty careful even with soldering of connectors (or cells in A123 battery packs).

http://www.flyinggiants.com/forums/showpost.php?p=791137&postcount=1699

its a dated thread, but the entire thread was on cooling issues. theory apart, is it possible that due to the frequency shifting properties of futaba, with the reckless frequencies floating around including cell phone towers, whether its possible that your 2.4 can have a lock out ? especially if its frequency hopping ? it may be possible with at least a dozen cell towers around you and your radio is switching frequencies ? paper theory may not be always correct and it may be possible even the chances are remote.

Actually the frequency hopping is the reason why FHSS (used by Futaba and Airtronics) is generally considered a better system.  You have to remember that it transmits on a frequency for 2ms, waits for 8ms, and then transmits on another frequency for 2ms and so on.  So even if 2 or 3 cell towers exist in the area, they do not affect the transmission really (it may cause small signal loss with in the 1000/(2+8) = 100 times the information is transmitted per second).

If you investigate forums like RCU and RCG, you can readily see that this "FHSS is superior" argument has broad acceptance.

your argument may be true regarding RC flying when there are 100 flyers flying at the same time. but here the situation is external interference from more powerful transmissions. abroad they have well controlled situations for rc flying but not so in india. may times mobile transmission due to interference is a mess, for example we had to resort of leased line as our GPRS connectivity got affected to a new tower erected by one XYZ (no names) operator.

Nobody is claiming that anything is totally interference proof.  I was stating what is considered the norm, which is easily verifiable by much deeper technical discussions on the international forums.

One thing is sure, the frequency shifting of Futaba is considered an advantage in general (that does not mean it is perfect), as opposed to it being the cause for lockouts.