what can be wrong? :(

[Jigs]

Hey all

Got my scx10 honco today Bought it second hand but its only been used like 5 times so its like new

I got it in the mail earlier today and tested in in the livingroom just to se if it worked properly.
And its works ok but when i give full throttle forward it kinda twitches like speed up and down by itself.. Kinda hard to explain it. when i push rewers its all fine.

I have the original motor and a Mtroniks tio Rock c spec esc.

Anyone have any tips on what can be wrong?

[johnnyh66]

does it have overdrive/underdrive gears and are you testing on carpet?

If no, could be a loose wire or short somewhere.
Check all the solder points, motor to esc connection and the rx plugs.

[Jigs]

Originally Posted by johnnyh66

does it have overdrive/underdrive gears and are you testing on carpet?

If no, could be a loose wire or short somewhere.
Check all the solder points, motor to esc connection and the rx plugs.

I tested it on hard wood flooring. Not sure what u mean with overdrive/underdrive gears. But if you mean the esc it has 2 modes. Crawling and normal driving. tested on both setting and same result... :(

I will go over all connections and se if i can find anything wrong. But im kinda new to the rc world so not quite sure what to look for really. But il give it a go

Thx for the fast reply btw

[devestator_x]

Do you have any other electronics to test in it? Waaaay back in the day I had a faulty esc that would sputter in reverse. Swapping recievers did not resolve the issue as I thoughtit was a radio issue. Swapped out the ESC and everything worked normally. You could first check to make sure the solder connections on the motor are solid. Other than that, Id take a guess that its a bad ESC.

[johnnyh66]

no problem.

OD/UD are gear sets from Axial that go inside the axle (differential).

With any combination of them installed (OD in the front and UD in the rear),
the front wheels will turn faster and the rear wheels will turn slower.

If a setup like this is run on a high traction surface, the rig can sort of hop around a little.


Do you know what esc it has?
Also, what kind of battery? It could be the battery is shot.

[Mr.Joshua]

I've had that happen due to the antenna wire contacting metal. I think it can also happen if your receiver/esc/antenna are too close to the motor.
Maybe pull out your antenna and receiver so they aren't touching anything, prop up the rig and try running it.

[Jigs]

wow you guys answer fast i have a Mtroniks tio Rock c spec esc and using a brand new Nano tech 2s 5800mah battery. I dont have any other esc to try with atm but i talked to the guy i bought it from and he is sending me the original esc in the mail. 2-3 days until i get it though.

I tryed to hold the car in my hand so that all wheels was in the air and throttled forward with same result. :(

About the OD/UD i have no idea :p its 100% stock exept the esc though.

[badhoopty]

is the drivetrain binding anywhere? are there any drastic driveline angles where you could see the ujoint maybe being slightly extended beyond its operational angle as it rotates and causing a bit of a bind/skip?

[devestator_x]

Well, if its doing it while suspended in mid air, then its certainly an electronic issue and not a gearing issue. If the new esc doesnt solve the issue, then it could be loose wiring like previously mentioned. Next step would be to pull out the motor, esc and reciever. Wire it all up outside of the truck and try it out. Make sure the antenna wire is far away from the other electronics. If it's still sputtering, you could try a different motor if you have one. If not you could try a multimeter set to DC current to measuer the voltage coming out of the ESC. If that seems to be ok and the voltage is nice and steady, then the problem lies in the motor.

Best bet though is wait it out and try the stock esc. Check for loose wires in the mean time while you wait.

[badhoopty]

before you go tearing into the electronics, disconnect the driveshafts and see if the motor still lurches like you described.

[Meatwad]

Or switch the motor wires and see if it happens in the same direction. If in the same direction, chances are its a mechanical issue. If the problem moves in the other direction, chances are its a motor or electronic issue.

[Jigs]

I am apsolutly amazed by all the replyes and helpful tips i have gotten in such a short time
Never before in any forum have i felt so welcome

I have looked over the electronics and i cant really se anything wrong with it. I will try with a nimh battery tomorrow and se if there is any difference. Other then that i think il have to wait until i get the original esc and try that.

One thing i am thinking is that i dont have the 2,4ghz controller and reciever. Its the old system with a crystal in the controller. u guys think that might be a problem causer? maybe picking up some disturbances?

ohh and i will try Meatwad and badhoopty`s tips

[devestator_x]

Hopptys idea is the best so far. Meatwad also has a good idea. More than likely the culrpit is the esc though, but thats just my own opinion as I had the same issue years ago (like in 1998 type long ago) I still use a Traxxas TQ system on 27mhz with a crystal and its flawless where I run. They arent all bad ;)

[Mr.Joshua]

Originally Posted by Jigs

I am apsolutly amazed by all the replyes and helpful tips i have gotten in such a short time
Never before in any forum have i felt so welcome


One thing i am thinking is that i dont have the 2,4ghz controller and reciever. Its the old system with a crystal in the controller. u guys think that might be a problem causer? maybe picking up some disturbances?

That is the set up that i was having interference issues with, i should have been more specific on the tx/rx question

Oh...and you just caught everybody on a good day

[SwampDawg]

long shot but, the antenae wire hasnt been cut (shortened) has it??
cuz they are tuned to/from the Rx/Tx (frequency). By cutting the length of antenae screws it up

[xturdfergusonx]

You said 2s?? Is your battery fully charged?? I have seen trucks do weird stuff either in cutoff or being very close to it.....

Just something to rule out.....

[Jigs]

Tryed taking off the driveshafts today to se if the same thing accured. And it did :( But i am now using a nimh battery 7,2v 5000mah and it allready seem way better... I dont think there are anything wrong with my lipo battery though. So must be the esc bugging alittle when i use a lipo on it :/

The antenna wire has not been cut so it cant be that. But last night i did a little run around livingroom again it was 1 place in the hallway the truck just stopped and started turning without me doing anything. This happend 2 times in the same spot.. Wierd i know :p must be some ghost messing with me :p

[Jigs]

Just ripped out the esc and connected a brand new motor to it. A roxx AR 55x2T motor. And the same result. when i hold a steady throttle it speed up and down. like its a power loss or something.
But im pretty sure its a esc problem now though. :/

So il be ordering a new esc. Any tip on what to get? i want one with brake and pref waterproof

Edit: I notised that the esc has a 35turn motor limit. and the guy i bought it from has used the original 27turn motor on it. Can that be why the esc is acting wierd?

Ok so i just talked to reseller of the esc here in norway and they said that its a common problem with those esc`s. :( Some problem with resistance or something. So the problem is solved atlest :P

Thank you all for your tips and help with this I will defiently stay in this forum as it seems like a really good community

[crawler nut]

Holmes Hobbies BRXL

[AsILayDying]

Originally Posted by crawler nut

Holmes Hobbies BRXL

+284729876 they are awesome ESC

Sent from my Samsung Galaxy Note (Phablet)