Tabushi

iTrader: (1)

Guys i have a question ...

Im using on one of my .12 200mm cars a OFNA micro failsafe :



The Ofna FS im using with 1.100 mah NiMH 6v 5 Cells battery pack and im VERY HAPPY with it ...

Now, i was needing another FS for my new G4 Evo car but the importer didnt have any Ofna FS anymore, so i just imported from USA (2 weeks waiting to arrive !!) a Futaba FSU-2 FS ( FSU-2 ) :




Now, the thing is that on the Futaba website just explain the function of a failsafe on the way we all know, but now that i receive the item on the manual says that CAN BE USED JUST ON NICADS (no NiMH allowed) ... and the text on the instructions is For use with NiCd batteries only, no alkalines or manganese dry cells. The discharge curve of alkalines and NiMH cells is different from that of the NiCD cells for which this unit was designed. Non-NiCD cells will not provide the warning at the appropriate time.

So ... my question is IS THIS REALLY TRUE ? ... i've using my Ofna FS and another Venom FS with NiMH without problems, what makes this Futaba one so special ?, or i dont have to worry at all ? ...

Thanks in advance, right now i dont think if installing the Futaba FS unit on my car o just order a new one from USA that is compatible with NiMH packs ...

thanks in advance as always guys ...

.

Dragon

What radio are u using anyway?

Most hi-end PCM controllers already have failsafe built in...

Tabushi

iTrader: (1)

Im using a Futaba 3PDF, wich does not have a failsafe built in ...


.

Dragon

I guess the reason y the state that NIMH cells are not suitable because of the voltage discharge curve is because its curve is more horizontal in the beginning then suddenly drops, unlike NICDs whose voltage curve is more consistant from start to finish.

SO... the "warning at the appropriate time" would probably mean that the unit might not have enough time to react to shut down the car when it detects the sudden voltage drop when your car is running at full speed.

WHICH MEANS... that OFNA one most probably work the same way just that it didnt bother to say so... haha

For me i would rather install a On board battery indicator...

Dragon

Speaking of failsafes... theres nothing on the market that protects against signal interferences from other drivers right?

Tabushi

iTrader: (1)

Yes, the OFNA and all the failsafes have that job too ... they break the car when they get interferences ...

.

Dragon

Anyone happen to know if Futaba's PCMs built-in failsafes can do that too? (freezing when getting interferences?)

I am using an old Futaba 3PJS....

Rapid Roy

Thats exactly what that radio will do.

Tabushi

iTrader: (1)

So guys ... they are all the same or its something SPECIAL on this Futaba Failsafe ? ...

thanks,


Pat

Rapid Roy

Here's a discussion on failsafes

http://forums.radiocontrolzone.com/a.../t-121838.html

This guy sounds like he knows what he's talking about, but I can't personally vouch for his knowlage on the subject.

Tabushi

iTrader: (1)

Any other inputr on this guys ?


.

Artificial-I

iTrader: (17)

Other than the battery fail safe, it should be fine.

As for the battery on a nimh, a perfectly matched pack or newer pack will be more problematic or harder to catch due to the sharp drop. As a pack ages, since its not just one nimh cell....but 5 in this case they will get out of synch overtime and provides a softer landing or a less abrupt run out rather than the quick sharp drop.

So it should work fine with an older out of synch pack.

Solara

iTrader: (17)

Tabushi

I too have 2 of those Futaba on my Serpent 835 and 950R (cause I am using some aftermarket receiver that does not have build in fail safe...)

On both of the car, (using 800mah AAA NiMh)....I ran the car in purpose about 6-7 tanks without recharging the batteries...usually, these 800mah can handle 30-45 minutes from fully charged, but I didn't charge them fully and keep running it.....both car at one point, STOP/BRAKE (pre-set) at the middle of the track with engines are at idle (of course, I picked the right time when very lilttle cars on the track to test the fail safe) with engines are at idle speed.........picked up both cars, and both fail safe work as I programmed.....

So, they both work with NiMh under "batteries in low-power" setting.........then I also tested the car running around 20-30mph speed and turn off the radio testing........they both worked as well.

Yes, that message (cannot work with NiCd) does scare me at the beginning....but batteries are batteries.....they give out voltage, and once the fail safe unit detect the low-voltage, it will kick in the BRAKE function....now, you should pick up the car ASAP, cause god know how long can those FULL BRAKE (still using power from the receiver pack) will hold...espeically those 1/8th monster with 3HP engine....

1 thing I don't like about this Futaba unit....they are TOO CHEAP about the cable, I have to buy an adaptor in order to mount the failsafe ntext to my throttle servo.........seems like Futaba designer expect every car's receiver location is right in front or next to the throttle servo.............

Tabushi

iTrader: (1)

Thanks a lot Rookie Solara !!! ...

I will install this little gadget this week and testit out this weekend ...

cya !