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Fail-safe feature not working

8K views 31 replies 4 participants last post by  sameera.c 
#1 ·
Hi guys,

I'm new to the forum. I own a GV JCT RC8 truggy. I'm not very experienced still and while I was bashing my truggy last week in a track which had some water, car ran into water pits every now and then. Most of the times when that happened, car missed the beat and engine stopped. However, fired-up back without much hesitation.
two days later I took out the battery pack and servos to clean them and put back together. Doing so, I dismantled the servo arms where I took a mental picture of how they were.
After I put them together, I don't think the throttle servo is working as it should. I tried fine tuning the servo arms but when the radio throttle trigger is at neutral, servo goes all the way back to brake the wheels. And I don't see the fail safe feature, which was told to be an inbuilt feature in the radio system, working. (it should only brake the wheels in the absence of transmeter signal if fail safe is working properly) But now it locks the wheels when the throttle trigger is not depressed and doesn't make any difference when radio is turned off.

Can some own please explain me what's happened? I really like to learn the logic behind these adjustments. (however, its damn hard to do it on my own)

Thanks in advance

Cheers
Sam
 
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#2 ·
Remove the throttle servo arm, turn on the TX then the RX, set the throttle servo adjust knob on the TX to centre. Re-attatch the servo arm at throttle neutral possition. Check operation.
Be sure you have fresh batteries in your TX and RX.

I hope this helps.
 
#4 ·
#5 ·
I got a manual with the car. its shows the diagrams but no pictures. However I think it originally came in that set up, according to what I remember. thanks for the link. it doesn't bringing up anything related though. However I found some other important materials there.

I did re-attach the servo according to what you told. But nothing changed. Then I had a look at the Rx and the fail safe unit. Rx LED is solid Green and fail safe LED is flashing Red. But still no sign of fail safe feature working.
 
#6 · (Edited)
Ok, lets start again.

Forget about the failsafe for now. That can wait till the throttle servo problem is fixed.

Take off the throttle servo arm and leave it off. Next turn on the TX then the RX and tell me if the servo turns normally when you use the throttle trigger in forward and brake positions.
 
#8 · (Edited)
Have you centered the throttle adjustment on the TX? If yes read on.

Ok, now plug the steering servo into the throttle socket on the RX and tell me if it does the same thing.
If it does, the RX has probably been damaged from the water and will need to be replaced.
If it works how it should, your throttle servo needs to be replaced.

The lesson learnt is don't run your car in water.
 
#9 ·
Seems like servo is causing the issue. When a swopped the Rx slot steering responds to the throttle lever. Works both ways. I tried the other way round as well. Throttle servo responds to the steering wheel, but only one way. No braking.

Thanks a lot for helping me out mate. Really appreciate it.

And one more thing. While I was meddling with the Rx the antenna wire broke. Is it alright if I connect the two ends? Or can I buy the wire separately or do I have to replace the Rx ?
 
#10 · (Edited)
A faster stronger metal gear servo is great for steering.

You might be better off money wise just getting a new radio set from HobbyKing. They are only about $50.

Glad I can help.
 
#12 ·
If you snapped off the Rx antenna, you need to replace it, 2.4g Rx the actually antenna is the last inch of the cable protruding from the case, all the rest if it is more or less extension cable. As you can see in the picture, the white/grey section is all lead and the actually antenna is the clear part right at the end. Hobbyking have replacement antenna you can buy, they are only 3 bucks.

Body jewelry Eyewear Audio equipment Gadget Rectangle
 
#13 ·
That's right Shrubbs, but will it fit his GV JCT RC8 truggy RX?

Not sure?
 
#14 ·
You are correct Wiz.. I had a look yesterday and the wire is soldered to the board. So I think I have to go for a new system.

guys do you think Turnigy is a good brand. below system will only $36
Turnigy GTX3 AFHDS 2.4ghz 3 Channel Radio System

Link
http://www.hobbyking.com/hobbyking/...GTX3_AFHDS_2_4ghz_3_Channel_Radio_System.html

And please let me know what are the good (I mean at my stage) brands considering the cost as well?
 
#16 ·
#17 · (Edited)
Id'e steer away from Turnigy gear. A Futaba 3PRKA is a good option if you want a cheap branded name radio. The TX antenna is inside the case so you cant break it off. See the link below.

http://www.futaba-rc.com/systems/futk3100.html

Expect to pay around $80.

Shrubbs suggestion is good as well, but nowhere near the quality of the Futaba. Your radio gear is the most important part of RC, do it once and do it right.
 
#19 · (Edited)
Unfortunatly, Quality costs a bit more. I'm celebrating your birthday Shrubbs in your absence here. Glug, glug!

Besides that the radio you linked to is as ugly as a camels butt. lol

Not that Iv'e ever seen one. (camels butt I mean)
 
#20 · (Edited)
BTW sameera. You do know that you have to push the throttle trigger away from you to get the brake working. Don't you?

It seems really obvious but I have seen people waiting for the car to brake at neutral possition on the throttle trigger.
 
#21 · (Edited)
Ya, that I'm aware of. thx for the advises and suggestions guys..

however I'm bit lost between the options here

I understand Futaba is a better brand. on the other hand the system Shrubber suggested has got some cool features.

what sort of cons do low cost systems like hobbyking systems have. in what areas am I compromising if I go for low cost system with more features?

all in all, what's would be the best system under 100 bucks? (understand there is no one answer, but even couple of suggestions would do)
 
#22 ·
When you click on the links, read the reviews on the radios further down the page. You will see what other people who bought them think of them and problems they have encountered.

IMO the Futaba I suggested is the best radio for under $100.
 
#24 ·
hi guys, finally I bought a Spektrum DX3C radio system. I suppose this is fairly a good one for some one at my stage. Hobbyman ppl also recommended it. my options were spektrum ($150) vs Futaba 2L which was $130.

Only feature missing in spektrum radio is ABS feature which was there in Futaba. Guys at hobbyman were telling me ABS won't do much difference. besides I also believe that learning the vehicle dynamics properly so that I can control my car even with the basic radio is the best thing.

However its easier said than done..

thanks for all the tips this far guys.. really appreciate taking your time to help newbies..
 
#25 ·
You really cannot go wrong with that radio, it is the exact same one as i use, as for ABS, who cares really it is not that important for smaller scales at all, 1/5th on road, yeah you want it then, anything else not so much.

When you need more receivers for other cars you buy, here is the link to the clone receivers, i use these in all my cars.

http://www.targethobby.com/spectrum...ceiver-dsm2-for-rc-car-rc-boat-p-4162169.html
 
#26 ·
I just checked you link Shrubber. But its unreal, isn't it. unit is 100 bucks in the store and they are offering it at $8, $15 all up with shipping. do you think its a real deal?

I'm thinking of buy it for future use. coz I got a receiver with my radio and this SR3100 is not going to do any difference in my case at the moment since my radio is only DSM, not DSM2. so i'm thinking of buying the one in your link as backup or for my next car
 
#27 · (Edited)
Replace the SR300 and sell it for $30 or there abouts and use that money to buy 3 of the clone SR310's, the SR300 is junk. I use the clone sr3100 in all my cars, they are faultless and much more responsive than the SR300.

Yes the store is for real, i have ordered 10 of those Rx off them. Postage is slow, about 3 to 4 weeks, but they have never failed me yet.

Here is the tread on Aus Rc about them: http://www.ausrc.com/forum/showthre...-Spekky-Receivers&highlight=cheap+spectrum+rx
 
#29 ·
When ever you need help, we are here to help you.
 
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