RC nitro car help. Looses signal WAY to early.

marc512

marc512

marc512

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15 Nov 2008
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Scotland / Blairgowrie
Been going out lately with my nitro cars. But i noticed on my rush evo it can get about 5m infront of me then it will take off down the street ( if i back of before it does it , it usely stops but when im giving it full it just goes crazy )

I have recently replaced the engine because the original T-15 engine blew up overheated massivly and theres no engine power left. It took of down the street and i spent 5mins chaseing it, when i got to it the engine was smoking like nothing on earth. So i bought a new XTM .18 for it. Last night i just finished of linking up the throttle etc and i took it out on the street.

I gave it abit of throttle and put on the brake. worked fine. Then i came back down towards me giving it abit more throttle and once it reached to the next door neighbours house it started making its way down the road. i ran towards it holding my finger on the brake but nothing was happening, then the engine died. Lucky i didnt put a lot of fuel in it so i can run it dry ( i cant find my after run oil so i gotta run dry )

What you think can be causeing it? im about to change the receiver from another car into the rush to see if that makes any difference. I have new batterys in the car and the transmitter.


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image of my rush with the new engine ( without the new throttle and longer fuel pipe. ). This link is from MY facebook album.

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show of time :) i do know my stuff about these cars. I have a rush evo (red one and in above pic) just for messing on and off road. My exceed infinity (big one) i use for going offroad and doing jumps. The speedy car winner pro i just use for going around carparks and up and down the road flat out :D
Exceed infinity - .18 CXP engine
Speedycar - Unknown 2 speed .15 engine highly tuned
Rush Evo - .18 XTM Race engine with highly tuned carb, hot racing glowplug, highly turned exhaust.
 
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viper_2003 said:
Failsafe?
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fail safe fails. I have one on my speedycar which i used on the rush before the engine change but it still drives off.

I was thinking maybe a battery pack instead of 4 Duracell batterys. There ment to give abit more voltage. Maybe my receiver isnt receiving enough? or its just ******?
 
I had the same kind of problem before when i had nitro cars. Never really found out what was causing it but in one buggy it would shoot off but the same set up in a different buggy would work fine.

Is the antenna on the rx damaged at all or cut? Could be the throttle linkage is sticking on when giving it full throttle. Try turning your car on and the transmitter. Leave the transmitter on but walk away from it with the car in hand and see if you get any twitching from your servos or if the throttle opens.
 
robgti said:
I had the same kind of problem before when i had nitro cars. Never really found out what was causing it but in one buggy it would shoot off but the same set up in a different buggy would work fine.

Is the antenna on the rx damaged at all or cut? Could be the throttle linkage is sticking on when giving it full throttle. Try turning your car on and the transmitter. Leave the transmitter on but walk away from it with the car in hand and see if you get any twitching from your servos or if the throttle opens.
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Im going to get my dad or somebody to walk down the street with the car ( engine off ) and see how far i can get before it starts twitching or how far before i cant use the throttle etc.

The gap is about 0.5mm idle and it gets full. We got this set up perfect. the antenna isnt cut or broke. But it may be broken inside the receiver ( iv never taken it appart so i cant be for sure. )

The car does twitch a lot when you first start it up. But once you start moving it seems to calm down.
 
If it is twitching bad before you set it away there much but a problem with either your servos or rx. If you can i would either try a different rx in it or full new radio gear. What are you using? AM FM or 2.4Ghz?
 
robgti said:
If it is twitching bad before you set it away there much but a problem with either your servos or rx. If you can i would either try a different rx in it or full new radio gear. What are you using? AM FM or 2.4Ghz?
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2.7ghz. I think FM. The servos are brand new. 8kg ones. Should be enough.
 
Well as I fly RC Heli's and Planes I would say maybe antenna damaged either on receiver OR transmitter. Do a range check. Dont pull your transmitter aerial up and walk away and you should get about 30 paces with aerial down on TX before glitching.

This is what we do with planes and helis, you could always set a fail safe too, to cut throttle when no TX input.

If it is aerial on RX (receiver) that is damaged, then very easy to put a new aerial on, or even replace with a whip antenna. More sterdy.

Could also be interference. Could be too near the battery pack or servos or engine. Maybe even a faulty on/off switch.

There is lots than can be the cause, you have to diagnose what it could be. I would range check 1st though.
 
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Magic_x_uk said:
Well as I fly RC Heli's and Planes I would say maybe antenna damaged either on receiver OR transmitter. Do a range check. Dont pull your transmitter aerial up and walk away and you should get about 30 paces with aerial down on TX before glitching.

This is what we do with planes and helis, you could always set a fail safe too, to cut throttle when no TX input.

If it is aerial on RX (receiver) that is damaged, then very easy to put a new aerial on, or even replace with a whip antenna. More sterdy.

Could also be interference. Could be too near the battery pack or servos or engine. Maybe even a faulty on/off switch.

There is lots than can be the cause, you have to diagnose what it could be. I would range check 1st though.
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I have just put the receiver from my exceed into the rush. It seems to be fine. I had my friend walk down to the end of the street (about 40-50m) and it worked but he said it was twitching a lot. Its only a 24mhz receiver. I will be buying a replacement receiver then but i dont know whats the best. Any ideas?
the battery box is directly above the receiver apposed to normal rushes there at the back. ( i put it on top because every time i hit a bump it flys off causeing it to go crazy ).
the failsafe on my speedycar is only there to stop the car if battery power is low. It doesnt work of its in range. Any ideas on good failsafes what cut throttle when theres no input?
 
If you using standard Duracell batteries to power the receiver and the servos then that could also be a cause, the servo will put a strain on the battery making the receiver go ga-ga.
 
IAmATeaf said:
If you using standard Duracell batteries to power the receiver and the servos then that could also be a cause, the servo will put a strain on the battery making the receiver go ga-ga.
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what batteries do you recommend? iv always used duracell for the cars and never had any problems. Was thinking of buying the battery packs but you need a charger what cost just as much (£40 all together). There ment to over volt to give servos 100% efficiency .
 
You can get a cheap charger and rx pack for around £20. The charger is a slower charger than most but will save you in the long run buying duracell's.
 
Have a look at www.overlander.co.uk for batteries etc. Good site.
As for what is the best receivers. I dont really know on cars, I have always been happy with JR and Futaba.

100% agree that using rechargable batteries is better in the long run. Wont cost you much and if you get a couple of packs you will be always charged up. Always use rechargable in planes and helis anyhow.

if you do buy a new receiver, make sure it is 27mhz, you could always have a damaged or badly fitting crytal in TX or RX?
 
marc512 said:
I have just put the receiver from my exceed into the rush. It seems to be fine. I had my friend walk down to the end of the street (about 40-50m) and it worked but he said it was twitching a lot. Its only a 24mhz receiver. I will be buying a replacement receiver then but i dont know whats the best. Any ideas?
the battery box is directly above the receiver apposed to normal rushes there at the back. ( i put it on top because every time i hit a bump it flys off causeing it to go crazy ).
the failsafe on my speedycar is only there to stop the car if battery power is low. It doesnt work of its in range. Any ideas on good failsafes what cut throttle when theres no input?
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I just got whatever was down the local shop, when you switch the transmitter off it kicks in.. isn't this what they all do. I wouldn't run anything without one having seen my mate total his RC Buggy from not using one!

something similar to this..
http://www.modelsport.co.uk/index.php?CallFunction=ShowSpecification&ItemID=23628

not bad for under £9..
 
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Ill go into my local shop tomorrow and see about failsafes there.

There are a few transmitters on ebay new with receiver 2 crystals and battery packs for the car and transmitter for £60 the lot. Seems quite a good deal.
 
Certainly try another receiver then transmitter if you have any, try another set of crystals.

Also; running it dry really won't make up for not using after-burn.
 
marc512 said:
servos only twitch when there either getting another signal, lack of signal, low battery or bad connection. In my case its lack of signal because the receiver is dead.
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I should rephrase this never got my point across, what I meant was the twitching servos are a sign something isnt right, as they drain the battery a lot which would not provide enough juice to the reciever, also servo's do go wrong and can have an effect on the whole system.
 
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