A fail-safe that was failing???!!!

[WA2FAST]

So I have a Venom Racing Failsafe that is supposed to return the servo to a set point when either the transmitter is powered off, out of range, or if the batterys in the receiver get too low. Last night I was running the car and everything was running just fine, then all of a sudden, it started to tweak out and kind of do it's own thing... I immediately ran up to it because we all know how bad run-aways can be. It was sitting there twitching all over the place, so I immediately killed the motor. I left the electronics on to see what it was doing and it was just twitching and going by itself but the servo speed didn't seem too low, but I turned the transmitter off and it would start to zero itself to the set point (on the break) and then start tweaking out again. I havn't run in this area before, but I honestly don't think it was interfearance since AM is much more suseptable to interfearance and a friend was running just fine (I have FM). The failsafe didn't have a "solid red light" like it says it is supposed to durring low voltage, but it was quite evident that it was dead since the servos were real slow after a minute of this.

I have heard of failsafes failing before... is this something to expect, or what? I thought that I was buying a fail-safe... not something that I now don't trust. I would have saved the money. Is there maybe a better one out there, or better insurrance that this won't happen?

I was running the rest of my 4AA batteries out before I dropped my rechargable pack in, but man... I didn't expect that.

 

[Çh®i§tiªñ]

If you run with regular AA batteries you can expect all kinds of issues combined with a failsafe. It has been my experience that you have to run with a rechargeable pack to be effective.

Just a thought.

 

[WA2FAST]

Well... maybe that is the case then. I wasn't sure, but like i said, I was just running it out before I switched to my new pack anyway. So you think that's the reason?

 

[El Pirata]

Ok I'm going to lay it all out as to why I think failsafes are just a waste of money and an additional item to fail in the electrical system.

Water: Most failsafes are too big to fit into most radio boxes which allows them to to be more suseptable to getting wet from splashes of water.

Total loss of power: A failsafe will be a fish out of water if you lose all electrical power, IE: a battery connection being lost.

Faulty failsafe: In a perfect world a failsafe is a great idea, however it is an additional item added in the mix that can and does fail itself. The more variables you add into a complex mix the higher the risk of something failing.


Running without a failsafe tips:

Low battery prevention: Always put fresh batteries in your RC before you run every day. This can get expensive however if you use rechargable NiMH batteries or battery packs you can charge them before you run each day. If you are using Alkaline batteries don't let them get below 1.3 or 1.4 volts and you will be fine.

Complete loss of power: I have seen it time and time again people using regular battery packs that you insert aa or rechargable batteries into the pack itself when they hit a bump the batteries will jar loose and thus completely lose connection. By simply adding a bit of foam below and above the battery pack will help prevent the battery back from losing connection. In the event you still lose connection a throttle return spring works wonders for closing the carb and thus stopping your RC. A common fault of most people on a return spring is that they add a spring but fail to test whether the spring will actually do the job it was intended for.

Water prevention: Plasti dip will work wonders for water prevention. Even if you don't opt to use plasti dip the foam you added in your radio box is generally enough to absorb 90% of the water entering your radio box and keeping it from your electrical current. You should also add the foam mentioned to keep the batteries in place below and above your radio receiver.

Radio interference: While most people didn't ready the fine print in their radio manual that states to check the intended range of their RC before using this really does work wonders for preventing runaways.

Nothing, not even using a failsafe will prevent runaways completely. I can honestly say that I have only once had a vehicle try to get away from me however before it got too far the throttle return spring stopped it and I was able to see I had forgotten to add foam in my battery box and thus a battery had bounced loose. Just my on the subject.

 

[Nitro_Keebler]

Make sure the adjustment on the failsafe didnt get moved/readjusted.

 

[Çh®i§tiªñ]

Yes, I would say that is why you were having problems. Most of the manufacturers of failsafes will even put in their documentation that they strongly recommend running with a rechargeable battery pack.

No matter what, failsafe or not, a hump pack or any rechargeable pack is suggested. It will save you money at the end of the day.

 

[RC10GT-GUY]

Reset it that might fix it.

 

[Ericke1]

Venom Failsafe

I had a friend who had the exact same problem. This is what he did to fix it. Remove the fail safe completelly, connect your throttle servo to the receiver box and make sure everything is working normally. Then shrink wrap your servo linkeages so that twitching/glitching is minimized. Then re-connect the fail safe, reset it (follow your instructions) and try it again. If this doesn't work, then you have a defective piece. I assume that you have checked your batteries.

 

[robriguez]

Since I have not received my new 6v hump packs I ordered 3 weeks ago grrrrr, I still run AA batts. I have had two rides take off after a bad landing due to batteries jarring loose so now I just put a zip tie around the batt pack before putting in my ride. No way they can come loose now.

 

[WA2FAST]

I have always zip tied the battery back before running... those batterys are NOT going anywhere if you do that. It was a case of low batteries, just annoying that it does that instead of what it is supposed to do unless the batteries dropped that fast due to the high torque servos. Doesn't matter anyway... I have a fully charged pack ready to go in... I just need to put a safety spring on... Any pic's of someones spring installed? I noticed that even when I turned my electronics off, the servo "bounced" the throttle open a bit since the internals of the high torque create inertia... that was annoying. Turning the thing off and having the servo open the throttle a bit.

Also, my failsafe does fit right in the box with my reciever with no problem... reciever is tiny, so is the failsafe... they both fit in there nice and snug.

 

[Rolex]

When I was using an AM radio and receiver, I had a runaway, WITH a fail safe installed. It was caused by a passing Tractor-trailer with a modified CB radio in it. It went WOT in a straight line. The fail safe didn't work because the car DID get a signal, but it got it from the CB, rather than from my radio. I switched to an FM radio, and so far I haven't had a problem.
If your battery pack in your car gets too low, you can have a runaway, and the failsafe won't help you. There won't be enough power to work your servos.
My recommendation is that you leave the fail safe in, but add a hump pack and a battery monitor. That's my set up, and it's as close to 'fail safe' as I can make it.

 

[WA2FAST]

So guess what? It was NOT the failsafe's fault afterall! I thought since I put the battery pack in and it was all fully charged and ready to go, I would be in good shape, so I took it out again yesterday. The same exact thing happened, about a half tank into running the car, all of a sudden, I didn't have hardly any control over it but it hadn't taken off... I ran up to it and the steering servo was just fine, but the throttle servo was freaking out! I was picking the front end up when it decided to go to full throttle for no reason, then it returned back to the brake after running half way up my leg... I then was finaly able to kill it and take er' home.

I took all electronics out of the radio box when I got home. Figuring it was the failsafe, I took that out of the loop and went directly into the reciever, same thing. I then thought that maybe the antenna was kinked or damaged maybe where it bends to go up the tube, but that had nothing to do with it. I then swapped channel 1 and 2 on the reciever to see if it was related to the reciever or not... and what happens? The servo continues to freak out as soon as it gets power... now on channel 2, not one... yet the other servo works flawlessly on either. I then unplugged it and plugged in a different servo to that channel and nothing... quiet as can be. I played with it for quite a while, no glitches... I then just let it sit on to see if it would start to freak out, let it sit on for over 10 minutes... no problems at all.

The damn servo is bad! All this time, looking like other things... it's definitely the servo. I am going to return this one and get a different one today.:trout: :sniper: :horsecrap

 

[Çh®i§tiªñ]

Good man!

and Good Luck!

 

[WA2FAST]

Well, I returned it to the store, they had no problem taking it back... especially since it looked like it had never been used (very clean, I didn't off road the car that day, I had my street tires on in a parking lot) and I had the reciept and everything that came in the box. I ended up returning that one and upgrading to the HiTec HS-925MG which is a coreless, high speed servo that still has over 100oz or torque... for a few extra bucks. While I was up there, I got a return spring as well... I should be about as safe as can be after I hook this all up. This servo is way faster than my old one... comes in at .08 vs .20 Should me muuuuuch more responsive.