Cogging/9920 Problem
 

I have started to get this quite often now.

I can use my truck and if I slow down or stop I can't accelerate again. It just won't move and the 9920 makes a very quiet humming noise. I can't stear either (which might show it isn't cogging because all electrics stop).

I have to unplug the batteries and plug them back in again.

I run a 7XL & 9920 with 20/66 gearing. It's a been cold when I've run it and nothing gets hot.

Do you use a UBEC and have you moved it at all?I've found that moving it just a few mm can make the difference between undriveable interference and no interference at all.Just a thought.

They say the UBEC doesn't create noise,but if it doen't then it sure is affected by it.needs to be kept away from esc and other electrics and facing away.

Edit: do you have another set of betteries to try?

I don't use a UBEC, I have one but took it off because of dreadful inteference. I use a small reciever pack, 6v/1200mAh.

No other batteries to try. :(

Check the solder connections on each end of your batteries. I had a similar problem and found that one of the tabs had come loose and was causing Intermittent issues like yours. It can be tricky trying to re-solder a set of batts especially if they are factory assembled. Maybe check to make sure the red jumper on the 9920 has not come loose also. Good luck.

I have had a look and they look fine but I've redone my batteries. Put new bars on, new wires. Redone all the connections anyway, as they needed a refresh. I'm just letting the glue dry then I'll run them, I noticed on a few the shrink-wrap has worped away, leaving the cell casing in view (silver bit) I wonder if when 2 cells touch each other, it short circuits it?

Jumper is on fine.

Could it be anything else? :(

Is your gear mesh right? Isn't it set to tight? What batteries are you using? Are they old/new?

Oldish batteries.

Can't be gear mesh, servo wouldn't stop if it was.

it might be your reciever

It could possibly be, I ran it today with batteries redone but didn't have a long enough run to test it (because my servo arm snapped). Looks alright, will take it out again tomorrow morning and see.

hate to scare you, but last time my 9920 did that, it was the last time. Before, I didnt have much cogging and then it got real bad, so when I drove it over to me, it(9920) started to smoke........hope thats not it though.



ps. I also noticed the steering thing as well

You use a external batteriepack;

the only three things that can happen are these;

1 losing connection between your esc and 'powersupply' (ext pack) or the pack is not powerfull enough.

2 receiver is acting up, or the transmitter is loosing signal with it and the receiver goes into 'failsafe mode'

3 last and the worst; the 9920 might have got a dead short in it, which takes all the power from the external pack.

You don't have got your BEC jumper on the 9920?

I only have the red jumper on the 9920.

I've tried a less powerful powerpack and it does the same. It could be that I have deans on them (to make charging easier) and they use really thin wires? Deans taking away alot of power maybe?

Although it makes sense that it could be the power pack, as if I have my batteries plugged in and power pack off, I can't go forward/backward either? Is that normal.

Well nick. I am having a serious cog problem to. I have tried different packs ubec and all. I can still steer mine while it is going chug alug. :D Let me know what you find.

Yeh, having a few bits of bad luck, fixed servo arm then went out to a place to use it and forgot the transmitter - doh!

Coolhand,

When did you purchase? I am having the same issue. Did you get it resolved?

THanks