Fail Safe

[NitroNewb]

I'm getting ready to order a fail safe but wanted to know if they are universal or are they brand specific?
Do they need a seperate battery to run them?
I was looking at this one (http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXHLV3&P=SM) for my Exceed but figured I'd check before ordering.
Thanks
GHM

 

[robmob]

They are not brand specific and connects between your receiver and throttle servo. No additional batteries required.

 

[NitroNewb]

I see on their description it says "REQUIRES: Use of NiCD or NiMH batteries, do NOT use ALKALINES connecting between receiver and throttle servo"
What does that mean??

 

[robmob]

You are actually reading 2 separate statements.

REQUIRES: Use of NiCD or NiMH batteries, do NOT use ALKALINES
REQUIRES: Connecting between receiver and throttle servo


You can’t use a 4-cell alkaline pack because of the way they discharge.

An alkaline battery will discharge in a diagonal line until it reaches zero. This will set the failsafe off much to soon since its job is to detect a voltage drop and go off.

A nimh or nicd pack will discharge in a horizontal line remaining at the same voltage until the very end when it dumps setting off the failsafe.

 

[NitroNewb]

So the 4 AA batteries that the servos connect to won't work?
Are there any fail safes that will work with what I have?

 

[robmob]

All failsafes are similar in how they operate.

 

[NitroNewb]

OK...now I'm lost.
Sorry.
You say in your previous post that" You can’t use a 4-cell alkaline pack because of the way they discharge".
Should I assume that the 4 AA batteries that are in a pack that the servos wire too are what your talking about? Or am I missing something.?

 

[david41990]

any are good not really brand specific

 

[ohmygahitscoby]

No, the battery case that requires 4 AA batteries will discharge, causing the fail safe to kick in. You want to use a NiCD/NiMH battery pack to keep it from discharging.


David: Some good ones are the OFNA fail safe and the Venom fail safe.

 

[jetmechG550]

What radio system are you using? Some radio systems have built in fail safe.

 

[olds97_lss]

Alkaline cells discharge differently than NiCAD/NiMH. They can't handle heavy loads like NiCAD/NiMH can. When they are under load, the voltage on them drops drastically. Pretty much any failsafe will see that as an issue and shut it down.

Fail Safes kick in usually around 4.6-5 volts. When you hit brakes (servo dead stop), it puts a heck of a drain on alkalines which may cause the failsafe to kick in.

Honestly, you'd be money ahead to get a 6V NiMH pack, charger and a fail safe. You'd be surprised how much better your servos perform with a rechargeable receiver pack. You get better speed/holding power out of them.

 

[david41990]

Most failsafes are good just make sure it fits nicely in your car

 

[NitroNewb]

Alkaline cells discharge differently than NiCAD/NiMH. They can't handle heavy loads like NiCAD/NiMH can. When they are under load, the voltage on them drops drastically. Pretty much any failsafe will see that as an issue and shut it down.

Fail Safes kick in usually around 4.6-5 volts. When you hit brakes (servo dead stop), it puts a heck of a drain on alkalines which may cause the failsafe to kick in.

Honestly, you'd be money ahead to get a 6V NiMH pack, charger and a fail safe. You'd be surprised how much better your servos perform with a rechargeable receiver pack. You get better speed/holding power out of them.

I had no idea about the 6V NiMH pack. So I can replace my 4 aa batteries with this?
And what about the AA's in the transmitter? It's a AM T-10 27.195MHz AM transmitter. Do those go too?

 

[ohmygahitscoby]

The transmitter is okay, its just the battery pack you will replace.

http://www.teamfasteddy.com/index.php?main_page=product_info&products_id=121. I would get this, but you will need a charger.

 

[chuck3]

nope, the Tx is fine running on AA's only the car needs ato run on a batt. pack.

 

[NitroNewb]

Which charger would go with the battery pack from teamfasteddie or are they all compatable?

I just looked quick at some 6V NiMH packs. I see they range in price and mAh, 650 up to 3000. The difference is???

 

[olds97_lss]

The higher the MAH, the more power they hold. Think of it like gas. A single AA holds a pint whereas a D holds a gallon.

Most receiver packs for 1/8 and 1/10 scale are 2/3A. Which is fatter than an AA but shorter. The most I've seen so far in a 2/3A is 1500Mah-1600Mah.

No offense to Fast Eddie, but I'd run at least a 1400Mah. A 1100mah (what FastEddie has) will do the job, just not as long.

He doesn't sell a charger for receiver packs that I could find. Just chargers for single cells.

I run 2500Mah AA Energizer NiMH cells in my remote. I think I have a 1100Mah in my jato, a 1200 in my buggy and a 1400 in my aftershock. By the time they are all even pretending to be dead, I'm so tired that I can't hold the remote up any longer anyway! lol

I don't know what an exceed is... may have looked at it, but some require a specific shape receiver pack. My jato can run a 5 cell hump or 5 cell flat, but my buggy requires a hump only and my aftershock requires a flat (in the supplied holder).

As for a charger, it depends on what you feel like spending. I like my charger as it allows me to charge my receiver packs, my transmitter and (if I made/bought an adapter) my heater.

Mines a MRC 959, but isn't sold anymore. The MRC 960 is pretty much the same with better buttons. I bought mine used shipped for $25, so the buttons aren't something I worry about!

I've also have a Dynamite Prophet Plus that I bought new about a month before I bought the MRC. But it doesn't seem to do as good of a job topping off the receiver packs. It does ok, just not as good as the MRC. It also doesn't charge my transmitter very well since it's made to only do 4-7 cells. So it peaks early when I use it to charge my transmitter. Typically I charge my receiver pack with the MRC and plug the dynamite one into my transmitter, just to get it going. By the time it peaks, the receiver is done and I plug the MRC into it to finish it off. Works well when I'm in a hurry...

There are cheaper ones out there.

Here's a couple links to decent 1600 packs:
5 cell Hump
5 cell flat

 

[sanjay]

i figure what i would spend on fail save for my 4 rc it would be better to buy a spektrum dx3 come with 3 receiver and now when u buy a spectrum u get 1 mail in rebate for a 3rd and they have built in fail save with a return spring ur great thay don't have a battery fails save but go with imax they have 1 the beep to let u know it lost range and a battery fail save

 

[NitroNewb]

Thanks everyone.
I just picked one up on Ebay.(http://cgi.ebay.com/Ofna-RTR-Hump-Ba...QQcmdZViewItem)
All the info helps. Like I said...I had no idea about this.
Anything else I should know about???
GHM

 

[CharliesTheMan]

I think a fail safe and a fuel filter are two important items, can't think of anything else off the top of my head