Hi guy's, I'm having trouble with either my fail safe or the receiver it self. This is what's going on, first the batt. are fully charged. When I put my venom fail safe on it seems to work fine UNTIL you start the truck up. Then the throttle servo "twiches" When I go wot you can hear the servo moving the carb linkage from the "twiching". Like your goosing the throttle on the transmitter. I thought it was in the fail safe so I got a different brand, same thing . Then I put a different throttle servo in same poop. But if I remove the fail safe completly it seams to work fine. So do you think it's the receiver? If it is would HPI stand behind it? Can I use a different brand, what do you suggest? Thanks for your help and time Pee Wee!!
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bad receiver?
- Thread starter pee wee
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Error401
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I have experienced this first hand, and your Rx is probably fine. Here's why. If you remove the FS and it acts fine, then it's not the servo or the Rx. Plain and simple. The FS is a gadget that filters the signal and determines if you have 1) enough power in your batteries (which you said were new), 2) determines if the Rx is getting a clean or existing signal (which it should if you're right on top of the truck). If either (or both) of these conditions are not met, then the FS sets the servo position to a predetermined position.
This is all fine and well if the FS is working properly, but I have personally witnessed more often than not ones that do not work properly. I got one of the Ofna micro FS's and it did the same thing you described. A racing buddy has the same one on his 1/8th buggy, and it does the same thing. Another friend has told me of witnessing the same thing in other units. It is infuriating to hear about this because the ONLY FS that I have seen or owned that actually worked reliable and is rock solid is the XTM unit that I have on my Lightning. I have not (personally) witnessed anyone else here local that has another solid unit (if they even run one).
I have heard that the FS units are designed and constructed to run at 4.8v, but all the dry cell packs and hump packs run at 6.0v, and this cooks the electronics in the FS. Then they start getting goofy.
Just my 2 cents, but there ya have it.
Whitt....
This is all fine and well if the FS is working properly, but I have personally witnessed more often than not ones that do not work properly. I got one of the Ofna micro FS's and it did the same thing you described. A racing buddy has the same one on his 1/8th buggy, and it does the same thing. Another friend has told me of witnessing the same thing in other units. It is infuriating to hear about this because the ONLY FS that I have seen or owned that actually worked reliable and is rock solid is the XTM unit that I have on my Lightning. I have not (personally) witnessed anyone else here local that has another solid unit (if they even run one).
I have heard that the FS units are designed and constructed to run at 4.8v, but all the dry cell packs and hump packs run at 6.0v, and this cooks the electronics in the FS. Then they start getting goofy.
Just my 2 cents, but there ya have it.
Whitt....
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Are you telling me that I've wasted 70 bucks on 2 different fail safes? I think your right on cooking the fail safe after a while, because it worked ok when it was new, lasted about 10 tanks. Do you run one on your savage? I like the idea of them but if there not going to last I'm not wasting more money. Thanks for your help Whitt! CYL
Error401
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I'm not saying it was wasted, but they don't seem stable at all. My buddy that run one in his buggy just goes on running it, though I took mine off because it was really erratic. I would suggest staying away from the micro units. The XTM FS I have is rock solid, but it's about an inch square and a 1/4 inch thick (much larger than the Ofna FS I had for my Savage. I think it handles the voltages and loads better than the micro ones.
No, I don't run a FS on my Savage anymore. I do however have an improved throttle return spring and a servo that has almost no resistance when not powered. TRS's are useful too, but only if the spring can actually move the throttle servo back to idle. I have run the Rx batteries down in the truck, and my TRS setup acted almost exactly like a fail safe. One other thing to mentio is my radio, the JR XS3 doesn't let the servo go wild when the batteries are getting low, it just starts ignoring any signal and acts like the power switch is turned off. Then the TRS kicks in and returns the throttle to idle. I don't know if that works with the stock radio or not.
Whitt...
No, I don't run a FS on my Savage anymore. I do however have an improved throttle return spring and a servo that has almost no resistance when not powered. TRS's are useful too, but only if the spring can actually move the throttle servo back to idle. I have run the Rx batteries down in the truck, and my TRS setup acted almost exactly like a fail safe. One other thing to mentio is my radio, the JR XS3 doesn't let the servo go wild when the batteries are getting low, it just starts ignoring any signal and acts like the power switch is turned off. Then the TRS kicks in and returns the throttle to idle. I don't know if that works with the stock radio or not.
Whitt...
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- #5
Whitt your radio is a JR XS3? I don't know jack about radios but I did look at that very same radio at the lhs today, NICE ! He said that is there newest one out, is that right? I didn't think the price was way out of line 239.00 what did you pay? Is this a digatal radio? Do you need digital servos? Told you I don't know jack about this lol . There's only one way to get answers, and with guys like you it is easy. Thanks man!
Error401
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I think that's what I got mine for. I think it's digital, but I'm running analog servos on it now. If you're in the market for a good radio, that'd be the one. I especially like the expo function on the throttle and steering channels. And the shifter is a button, not a switch. BAM, you're in reverse, BAM forward again. No more fiddling with the switch. There are a ton of other features, but the best is the synthesized frequency. No more buying and swapping crystals at the track or the bash zone. What freq am I on? What's not taken is a better question.
Nowdays, if you're looking to get a new radio, save up and get something you can grow into, not out of. Pee Wee, next time you're at the LHS, ask them if you could read thru the manual for that radio, take some notes and post any specific questions here. Me or someone else will give ya the scoup on it. Don't let all the buttons and computer gadgetry on that radio intimidate ya, you would not believe how much better my Savage and lightning drive now with the "tuning" that you can do in the radio.
Nowdays, if you're looking to get a new radio, save up and get something you can grow into, not out of. Pee Wee, next time you're at the LHS, ask them if you could read thru the manual for that radio, take some notes and post any specific questions here. Me or someone else will give ya the scoup on it. Don't let all the buttons and computer gadgetry on that radio intimidate ya, you would not believe how much better my Savage and lightning drive now with the "tuning" that you can do in the radio.
ok i know that the Vfs unit dont work with the savage radio. Vemon said they fixed it but my dad got one for his savage and it did nothing. So if you have a stock savage radio and the Vfs that might be why. But the Vfs unit shouldnt work with any airtronics but i have a mx3 and it works just fine i have had my for about 20 tanks or so. So it is a little stange.
Error401
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Doug, I'd heard someting about that. I'm pretty sure that the stock Savage (and micro rs4) radios are made by airtronics. Decent radios (IMO) for what they are, and a ton better than that POS that traxxas puts out (and yes I do have a traxxas radio in the shop, and no it's not in anything).
robriguez
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I have the mini ofna failsafe in all three of my rides (LD3, Inferno 7.5, HPI NMT) I have never had any of these problems on my throttle servo. I have the stock Airtronis radio and servos on the LD3. I have the stock HPI radio and servos on the NMT. I have an XS3 with HiTech servos on my 7.5 and all work perfectly.
I do have some steering throttle glitches on the LD3 where I can hear the servo twitching but I dont see or feel the wheels move.
I do have some steering throttle glitches on the LD3 where I can hear the servo twitching but I dont see or feel the wheels move.
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- #10
Ok here is the latest twist. Now with the fs disconnected the throttle wants to, I dont know if the right word is stick but the throttle does not completely go all the way back to an idle right away and I'm talking just a split second for to idle, then other times, and this has happened a few times now where the throttle just plain sticks and the truck takes off ,me running after it. ha ha. Then it will idle right like it is supposed to. All of this happens only when the truck is running not on the bench there you can play with the throttle all day and it works fine .What the fu-- is going on? There is a few strands on the antana that got ground off , but that was a while back and it did not seem to hurt any thing then, just trying to come up with any ideas Should I see if hpi will look at the receiver? or just buy the jrxs3 and be done? Right now I'm afraid to fire it up because I dont know what it's going to do!! Thanks guys for helping me out with this one.
Pee Wee
Could it be the crystals? Should I try that?
Pee Wee
Could it be the crystals? Should I try that?
Error401
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Rob, it is good to hear that the ofna FS does work for some folks. I'd be willing to bet that the guys here (as well as me) got a bum batch. I've seen that happen with computer components before. I got an Asus mobo at a local shop and the voltage regulator on it was shot. Took it back, swapped it for the same model (from the same lot), and it did the same thing. Anyway, my only experience with the ofna FS was from what I've seen and experienced. Which now leads to the next step...
Pee Wee, sounds like you have either an RF issue or something is bad in your raido. If you have a bash buddy with another HPI radio, borrow it, put you Tx crystal in it and try running your truck. Tie the beast to a pole or something to keep it from running away also. Depending on what happens, you'll know if your Tx is good or not. The frayed antenna might have something to do with it, so I'd put some heat shrink on that spot to keep the wires from making intermittant contact (just to be safe). Another suggestion would be to unhook the installed throttle servo, plug a spare into that channel, fire up the truck and see what the (now dangling) servo does. As a last resort, take the whole radio system out of the truck, make sure the throttle linkage stays at an idle by using some kind of throttle return spring (rubber band, ducttape, etc), fire up the truck, hold the ball-o-radio close to the truck and see what the servo do. If they act up, move away slowly until they act right.
It sounds like you might have an interference problem. Make sure there are no loose metal to metal things happening on your truck. When two pieces of metal rub at high frequency (like when the truck is running and vibrating) they create a broadband RF signal that "jams" the true radio signal. Sometimes composite pipes rubbing on aluminum will do the same thing since it's a carbon fiber/plastic mix and the carbon and aluminum makes RF noise. check the engine deck screws too. These will work their way loose and vibrate in the holes making RF noise also.
I hope this hasn't numbed anyones noodle, I know mine is a bit numb right now.
Whitt...
Pee Wee, sounds like you have either an RF issue or something is bad in your raido. If you have a bash buddy with another HPI radio, borrow it, put you Tx crystal in it and try running your truck. Tie the beast to a pole or something to keep it from running away also. Depending on what happens, you'll know if your Tx is good or not. The frayed antenna might have something to do with it, so I'd put some heat shrink on that spot to keep the wires from making intermittant contact (just to be safe). Another suggestion would be to unhook the installed throttle servo, plug a spare into that channel, fire up the truck and see what the (now dangling) servo does. As a last resort, take the whole radio system out of the truck, make sure the throttle linkage stays at an idle by using some kind of throttle return spring (rubber band, ducttape, etc), fire up the truck, hold the ball-o-radio close to the truck and see what the servo do. If they act up, move away slowly until they act right.
It sounds like you might have an interference problem. Make sure there are no loose metal to metal things happening on your truck. When two pieces of metal rub at high frequency (like when the truck is running and vibrating) they create a broadband RF signal that "jams" the true radio signal. Sometimes composite pipes rubbing on aluminum will do the same thing since it's a carbon fiber/plastic mix and the carbon and aluminum makes RF noise. check the engine deck screws too. These will work their way loose and vibrate in the holes making RF noise also.
I hope this hasn't numbed anyones noodle, I know mine is a bit numb right now.
Whitt...
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Whitt it appears that it was bad crystals. It seems to work fine now, hell I even put the FS back in and that is fine also , for now anyhow. I'll be back if this does not work for long. Thanks man for your help!!